Solutions to Coastal Disasters 2005

2004 HURRICANE SEASON AND STORM SURGE In May forecasters with the National Oceanic Atmospheric Administration (NOAA) predicted an above normal activity for the 2004 hurricane season citing warm Atlantic sea surface temperatures and lower wind shear and surface pressure (NOAA 2004). In August this forecast was downgraded slightly citing weak El Nino conditions increasing Caribbean and Atlantic wind shear weakening hurricane formation. The season ended up with 16 tropical depressions, 15 named storms, 9 hurricanes, and six major hurricanes, placing it the third most active year behind only 1950 and 1995 (Bell et al. 2004). The most significant storms were Hurricanes Charley, Frances, Ivan, and Jeanne, which all made landfall in the state of Florida. This was the first time four hurricanes have hit one state in a season since four hit Texas in 1886. (Bell et al. 2004). Throughout the 2004 season NOAA's Center for Operational Oceanographic Products and Services (CO-OPS) recorded water levels and associated storm surge along the East and Gulf coasts. The primary physical components of storm surge are (1) water level elevation due to wind stress produced by a storm, manifested as water pushed toward the shore, and (2) water elevation resulting from diminished atmospheric pressure. Complex hydrodynamic phenomena such as tidal current interaction with bathymetry and topography, wave action, and seiche may also be present during a major coastal storm, and can be additional components of storm surge (Hovis 2003). Storm surge, for CO-OPS mission purposes, is computed simply as the difference between the observed water level and the predicted tide level. During the 2004 season recorded surge levels were highest during hurricane Ivan, however, each storm produced surges of varying degrees and occurances throughout Florida.

The population of the coastal zone continues to grow. As more people choose to live or vacation on or near the coast, the impacts on and dangers posed by the environment increase in potential and consequence. Those responsible for planning for, preventing, mitigating, or recovering from natural disasters need data in order to make good decisions. In the abstract for a paper titled The Coastal Component of the U.S. Integrated Ocean Observing System, Dr. Thomas C. Malone, Director of Ocean US, summarized the problem: "The combined effects of human activities and natural variability present significant challenges to the goals of protecting, restoring, and sustaining coastal ecosystems. Meeting these challenges and resolving conflicts in an informed fashion will require (1) more timely detection and prediction of environmental changes and their consequences and (2) more timely access to relevant environmental information." (Malone, 2003) The Integrated Ocean Observing System (IOOS) is being developed to insure timely access to the data and information required to improve (1) climate predictions and the effects of changes in the weather on coastal populations; (2) efforts to sustain and restore healthy coastal marine ecosystems and living marine-resources; and (3) compliance monitoring and evaluations of the efficacy of environmental policies. Many separate programs have been created for collecting, managing, and analyzing data from the coastal ocean for a myriad of purposes, resulting in too much redundancy, difficult access to the data, and little coordination. IOOS is intended to provide comprehensive and timely data in a more cost-effective manner. The importance of IOOS to coastal managers and other professionals is significant. More, better, and easily accessible data on coastal sea and weather conditions will allow federal, state, and local officials to make well-founded decisions on predicting and mitigating the impacts of coastal storms, harmful algal blooms, or other disasters, as well as plan a recovery effort. The interagency Ocean US Office was created in 2000 to integrate existing and planned elements to establish, over the next decade, the sustained ocean observing system that will provide the common data needed by research and operational agencies. The purpose of this-paper is to review the purpose of and actions underway to create IOOS, describe how data may be accessed and used, and to solicit input from the coastal community about how the data may be made more useful for predicting and mitigating the impacts of coastal disasters.

A wave transformation model, SWAN, is used to simulate wave conditions with a high spatial resolution in Penobscot Bay and Machias Bay in the coastal Gulf of Maine, The motivations are to provide forecasts to assist mariners, recreational boaters and others, and to develop a database of hindcast information that can be used for engineering applications. Since NOAA provides both hindcast and forecast wind fields, an automatic system is set up to provide 12-hour hindcast and 48-hour forecast wave fields, which may be used to prevent future coastal disasters. Model results are compared with several field measurements to evaluate the reliability of the wave hindcast and forecast system.

In this paper, a dynamic warning system to forecast inland flooding associated with typhoons and storms is described. The system is used operationally during the typhoon season to anticipate the potential impact such as inland flooding on the coastal zone of interest. The system has been developed for the use of the public and emergency management officials. Simple typhoon models for quick prediction of wind fields are implemented in a user-friendly way by using a Graphical User Interface (GUI) of Matlab. The main program for simulating the tides and depth-averaged tidal currents was also vectorized for the fast performance by Matlab. By pushing buttons and clicking the typhoon-paths, the user is able to obtain real-time water level fluctuation of specific points and the flooding zone. This system would guide local officials to make systematic use of threat information possible. However, the model results are sensitive to hurricane path, and it is yet difficult to provide accurate information to local emergency managers.

Coastal inhabitants experience sea level rise and fall, hourly, daily, weekly, monthly, and yearly and so on, governed by the astronomical tides, and a host of other factors. Meanwhile, there has been an accelerated migration into these zones by the populace of the United States (US). The recent census of the US indicates that greater than 50% of the nation's population resides in the coastal zone including the Atlantic and Pacific seaboards, the Gulf of Mexico, the Great Lakes, Alaska and Hawaii. Accompanying and facilitating the migration has been property development which has been increasing at an increasing rate. Meanwhile, reports of sea level rise and thus encroachment of the coastal ocean into these developed areas is raising serious concerns. But, what are the rates of variability, and the overall trends, over local to regional to global spatial scales? These are questions which coastal scientists, managers, builders, planners, developers, residents, and public officials, amongst others, would like to have answered factually. And this point cannot be overemphasized. However, in order to properly answer the questions posed regarding future adjustments in sea level, we must know past and present rates of rise. In this report, we will delve into these questions attempt to provide factual estimates based on the actual records. We will focus on the eastern seaboard of the US from Atlantic City, New Jersey to Charleston, South Carolina.

The National Weather Service (NWS) is responsible for forecasting stages for the major rivers in the United States. The Lower Mississippi River Forecast Center (LMRFC) is responsible for forecasting river stages on the Mississippi River below Chester, IL, on the Ohio River below Smithland Lock and Dam, IL, and continuing from the confluence of the Ohio-Mississippi to the Gulf of Mexico. The LMRFC prepares and issues daily forecasts for twenty-one locations along the mainstems of the lower Ohio and Mississippi Rivers. A unique forecast problem is the forecasting of stages on the lower Mississippi River when a hurricane induced storm surge is present. Storm surge waves move rapidly upstream and can cause significant damage and delays to barge traffic along the Mississippi River. The LMRFC has combined the NWS Dynamic Wave Operational Model (DWOPER), a one-dimensional unsteady state flow model, on the Mississippi River with output from the Sea, Lake, and Overland Surge Heights (SLOSH) model. The SLOSH model generates a storm surge hydrograph on the Mississippi River at a pre-selected grid point near West Pointe a la Hache, LA. This hydrograph is used as a downstream boundary in DWOPER to produce stage forecasts as a hurricane storm surge travels upstream on the Mississippi River.

A comprehensive analysis of storm damage potential was performed along the Texas coast centered about Clear Lake in Galveston Bay for the Johnson Space Center, NASA. The study dealt with numerical modeling of tides and frequency analyses of storm surge elevations associated with historical tropical and hypothetical storms to obtain extreme event storm surges. Results of the analyses were used to evaluate various alternatives for providing hurricane flood protection.

Typhoon Maemi landed on the south coast of Korea and caused a tremendously severe storm surge disaster in Masan city on September, 2003. The tide gauge in Masan Port recorded the storm surge of a maximum of approximately 2.4m, which resulted in heavily flooding the residential and commercial area facing the Masan Bay. And almost all the underground facilities suffered from the inundation by the storm surge. The numerical prediction of inundation due to storm surge was carried out in order to propose the future prevention system. This paper also describes the results of field survey and the validity of the inundation simulation.

The study utilizes two state-of-the-art computer models to predict storm surges and surface waves in the Mobile Bay estuary, Alabama. Both numerical models have the capability of resolving the complex geometry and moving boundaries associated with coastal flooding. Two storm events are simulated for a period of 16 days in September 2002 when Tropical Storms Hanna and Isidore passed through the region. Good agreement between the modeled and measured water levels at five tide gauging stations in Mobile Bay has been found. The surge model (ADCIRC) shows that the majority of Dauphin Island and the south stretch of AL Highway 193 were flooded by TS Isidore. Strong currents over 1 m/s are predicted by the hydrodynamic model. The third-generation wind wave model (SWAN) reveals the spatial distributions of wave heights and wave periods in the Mobile Bay estuary. This enables us to estimate the elevated sea level owing to the breaking of surface waves on the inundated barrier island and roadways. The methodology of coupling the surge and wave models can be used to improve the design of coastal infrastructure and to facilitate hurricane emergency management.

This study involved creation of nine two-dimensional, depth averaged computer models to simulate storm surge inundation along Florida's Southeast Coast. The work was supported by the District 4 office of the Florida Department of Transportation. District 4 covers five coastal counties in Southeast Florida. The design storm surge simulations provide, in addition to other information, the flow parameters required to estimate bridge sediment scour depths for those bridges contained within the model mesh. Spring tides as well as the 50-, 100-, and 500-year return period hurricane storm surge events were simulated. These simulations provided characterization of the flows through the bridges during design flow events. The characterization includes the flow rate through the cross sections, water surface elevation at the bridges, and the velocity magnitude and the flow skew angle to the bridge piers. With this information, District engineers may calculate contraction and local scour for existing or proposed bridges as well as calculate design deck elevations and vertical clearances. This work provided the groundwork from which to perform the FHWA-mandated Scour Evaluations of the bridges included in the models. The work will also provide a significant cost savings for performing preliminary design and evaluation (PD&E) studies and Bridge Hydraulics Reports (BHR) for new or replacement bridges within the models' domain. Additionally, the FDOT may employ these results in both the development of evacuation recommendations and in prioritizing bridge inspections during post-storm evaluations.

An empirical formula for typhoon-surge height at Ken-Fang Tidal Station was proposed in the present paper, basing on its corresponding typhoon property. The typhoon property analyzed in the present paper includes the typhoon-center atmospheric pressure, the typhoon-near-center wind speed, typhoon-storm radius, the typhoon distance from the typhoon center to the considered tidal station where typhoon surge is measured, and the typhoon-moving track against Taiwan Island. The study reveals that the higher the typhoon-center atmospheric pressure, the larger typhoon-near-center wind speed and the bigger typhoon-surge height; the smaller the typhoon distance, the larger the typhoon surge height. The proposed empirical, relationship of typhoon surge height includes three typhoon variables, such as the typhoon wind speed, the typhoon storm radius, and the typhoon distance, as well as three empirical coefficients to be determined. The three empirical coefficients were then analyzed, based on the 19 sets of measured typhoon-surge data at the Ken-Fang Tidal Station in I-Lan County, eastern Taiwan between 1991 and 2001 through a regression analysis. Two storm surges measured at the Ken -Fang Station, caused by Typhoon Herb (1996) and Typhoon Doug (1994), were simulated by the proposed formula as well as by a numerical model of Ou et al. (1999) for comparison. The comparison reveals that the proposed empirical formula has an acceptable success in storm-surge prediction at least at the Ken -Fang Station.

As people and businesses continue to develop and enjoy waterfront properties, the demand for coastal engineering and expertise will certainly increase. Wave modeling can be helpful at the design stage of a project as it can help the owners install a marine structure that is designed to perform in the site specific environment. Hindsight wave modeling can also be helpful to owners, marine contractors, and marine insurers as the parties try to sort out the cause of property damage after some particular event. This paper describes the wave modeling effort undertaken as part of a forensic analysis following damages to in-harbor structures located in Charleston, South Carolina as a result of Hurricane Floyd. A description of the modeling techniques utilized, sources of data used in the evaluation, an analysis of results, as well as a discussion of legal issues regarding such a forensic analysis are provided. Wave models were developed both for offshore waves entering the harbor through the entrance channel and for wind-generated in-harbor waves. The results of the Hurricane Floyd modeling were compared to standard return period storms to determine if the storm exceeded typical design criteria. Several interesting results were obtained from the analysis. For the project site, the worst case wave conditions were not generated by large offshore waves entering the harbor. A narrow but long fetch to the north along the Cooper River produced the largest waves. Shoreline structures also contributed to the observed structural damage by concentrating reflected wave energy.

Tropical cyclone events are important to the design of coastal structures in many locations; however, estimation of the extreme conditions associated with such events can be subject to significant uncertainty due to limitations in the historical data. This paper describes a Monte Carlo approach to generating a synthetic tropical cyclone database that encompasses the characteristics of the historical storm population. A sample application for evaluating extreme wave heights for a location in southern Madagascar is provided.

Hurricane Hugo (a Class 3 hurricane) impacted South Carolina beaches the night of 21 September 1989. It produced a 15-foot (ft) surge at Isle of Palms and an approximate 10-ft surge in more northerly sections of the developed coast. Peak surge of ~ 20 ft occurred along an area where little development existed. Beach response and damages were found to vary based on the prestorm condition of the beach. Four beach types and their response are described herein. Type (1) Beaches—Stable shorelines with a single, high foredune (eg, Litchfield Beach). Dunes exceeding a width of ~ 80 ft at the base withstood the surge and waves of the hurricane with negligible damage to property. Dunes, less than 80 ft wide at the base were more likely to breach and overwash. Emergency dunes tended to perform well. Type (2) Beaches—Eroding shorelines with a low dune (eg, Pawleys Island). Damage was extensive because of the volume deficit on the beach. Emergency dunes performed poorly because of exposure to normal tides. Type (3) Beaches—Accreting shorelines with multiple, low dunes (eg, Isle of Palms). Rapid accretion along some South Carolina beaches precludes formation of high dunes. Backshore areas become stabilized with vegetation before gaining height as more seaward dunes form and trap windblown sand Hugo's surge overtopped such areas and produced extensive damages to older properties not meeting today's building and elevation standards. Emergency dune construction was successful and long-lasting. Type (4) Beaches—Eroding, armored shorelines with no dry beach. Typical shore-protection structures were too low and inadequate to absorb the surge. Many seawalls and bulkheads collapsed along with habitable structures, producing damages similar to Type (2) beaches. South Carolina's experience during Hugo and its aftermath offers several lessons for beach maintenance along other sedimentary coasts.

Southeast Louisiana is extremely vulnerable to damages caused by hurricane storm surges. Densely urbanized population centers are surrounded by open water and wetlands. Storm surge protection of these population centers is currently provided by levees some of which were designed as early as the 1960s. The New Orleans District of the U.S. Army Corps of Engineers has been seeking more advanced design methods to ensure that current and future levees achieve the authorized levels of protection. The ADCIRC model provides the best available design tool to fill this need.

The City of Norfolk, Virginia was severely impacted by Hurricane Isabel in September 2003. The storm's waves and surge caused major beach erosion and nearly removed the protective dune in many areas across the City's shoreline. The City evaluated the condition of the shoreline after the storm and decided to implement a dune restoration project along approximately 5.5 km of the Ocean View shoreline from 14^th View Street to Warwick Avenue. The project consisted of a protective dune designed to resist a 5-year return period storm, with additional material placed on the beach. Project construction began December 15, 2004. This paper details the analysis of the anticipated performance of that project, including SBEACH modeling and shoreline change analysis. Results indicate that while some adjustment of the berm is expected during the first year as the project equilibrates, it is anticipated that the dune fill will remain in place assuming no significant storm impacts. Considering long-term shoreline change rates, the mean high water line may retreat back to pre-project conditions in 2.5 to 3 years in several localized "hot spots" and 5 to 6 years in other areas, without storm impacts. Should a storm similar in magnitude to Hurricane Isabel occur during the project life, SBEACH modeling results indicate that more than half of the dune volume may be lost offshore or pushed landward. Although some remnant dune protection may remain, the occurrence of a storm of this magnitude would necessitate additional dune restoration in the project area.

The shoreline of Carteret County consists of 80 miles of ocean coast reaching approximately 40 miles north and west of Cape Lookout, North Carolina. The county's primary industry is the tourism related to beach visitation and sport fishing. The ocean shoreline of the county is barrier islands and tidal inlets including the high non-overwashed Bogue Banks and low washover barrier islands, Shackleford and Core Banks, north and east of Beaufort Inlet. Of the county's barrier islands, only 26 miles (Bogue Banks) are developed. The remainder, Shackleford and Core Banks, are held in perpetuity by the National Park Service in the Cape Lookout National Shoreline. North Carolina, including Carteret County, experienced five hurricanes from 1996 through 1999, four of those making landfall as hurricanes, and one as a tropical storm downgraded from a hurricane. Hurricanes Fran, Bertha, Bonnie, Dennis, and Floyd set in motion a series of political, engineering, and construction activities unprecedented for coastal municipalities in Carteret County. Those activities started in 1997 with the appointment of a Beach Preservation Task Force to study the feasibility of a regional beach nourishment program. Since then, the county and municipalities of Bogue Banks have implemented several beach nourishment projects funded entirely with local funds. Nourishment, totaling over 4.6 million cubic yards, was added between 2002 and 2004. An additional ~ 2 million cubic yards will be completed in 2005. Residential and commercial properties on Bogue Banks generate over 42 percent of the tax revenue for the County of Carteret while requiring expenditure of only 5 percent of the county budget to provide services to the barrier-island communities. Of the total property taxes collected, a significant percentage (Emerald Isle—26 percent, Pine Knoll Shores—46 percent, Indian Beach—64 percent) of the total is derived from oceanfront property. Destruction of barrier island property was considered a direct threat to the economic base of the community. The paper describes how three municipalities responded to erosion, established funding mechanisms, held referendums, and implemented projects within about two years after initiation.

Tropical Storm Isabel left its mark on Maryland's coastal areas, producing tidal flooding consistent with a 75- to 100-year event. The coastal zone of Maryland, much of which is less than 5 ft above sea level, comprises two-thirds of the total land area of the State. Bordering this coastal area are over 7,700 miles of shoreline (approximately 69% are retreating), which are affected by a variety of hazards. Impacts from Isabel's storm surge included changes in the shoreline and widespread flooding of low-lying communities. In the aftermath of the storm, the Governor's Bay Cabinet requested an estimate of the amount of sediment released to the northern Chesapeake Bay from storm-related erosion. The authors contacted local planners throughout the State and summarized shoreline changes attributable to the storm. Although anecdotal information abounded, quantifying sediment losses proved difficult. Extrapolating from a rough estimate of the length of shoreline eroded in a single county, the authors determined that Isabel accounted for about 15% of the acreage lost from the Western Shore of the northern Bay in an average year. Coastal planners and managers are taking advantage of heightened awareness and lessons learned to improve planning for coastal hazards and surge events. Among these efforts were (1) a conference addressing the coastal management implications of the storm and (2) the development of an Internet mapping application that centralizes access to shoreline hazard information and data. The latter will assist coastal managers and the public in targeting appropriate shoreline protection and restoration options.

This paper focuses on description of selecting 95 historical tropical and extra-tropical storms and predicting extreme high water levels from these storms in Chesapeake Bay. A regional scale hydrodynamic model ADCIRC (Luettich et al. 1992; Luettich and Westerink 2003) is used to predict water levels and currents under high surface winds and low atmospheric pressure associated with the passage of storms. For tropical storms, surface wind and pressure fields were generated from a Planetary Boundary Layer (PBL) model (Cardone 1977; Cardone et al. 1992) and storm tracks were obtained from a North Atlantic tropical storm track list (http://weather.unisys.com/hurricane). For extra-tropical storms, wind fields were extracted from a long-term wind hindcast database by the Meteorological Service of Cananda, formerly Atmospheric Environment Service (AES), (Swail et al. 2000) and the reanalysis project database (Kalnay et al. 1996) by the U.S. National Centers for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR). The pressure fields were obtained from NCEP/NCAR database. Validation of PBL, AES, NCEP/NCAR winds, and model water levels were compared to data collected from 12 NOAA meteorological stations along the perimeter of the bay. Overall, model results show a good agreement with measured wind and water levels. A key to the successful modeling was representation of the topography of river tributaries, which flooded during the storm to contain large water storage at peak surge.

This paper presents the results of a statistical study to predict the wind speeds at tropical cyclone (including hurricane) landings in (or passing nearby) a specified area on the Florida coast, and compare with the landfall wind speeds of four hurricanes landed on Florida coast in 2004. Tropical cyclones which landed or passed nearby the Florida coast are selected from the hurricane database HURDAT. In the present study, the HURDAT data (recently revised version) are statistically analyzed; in particular, emphasis is placed on estimation of extreme wind speeds at the time of landing and passage nearby. The Florida coast is divided into 15 districts, and frequency of occurrence of landings and extreme wind speeds are estimated in each district. It is found that wind speeds of four hurricanes landed on Florida coast in 2004 are all below the predicted extreme wind speeds for design and safety consideration.

This paper details the impacts of Hurricane Ivan upon three monitored beach restoration projects constructed along the NE Gulf of Mexico shoreline. Ivan made landfall in the early morning hours of 16 September 2004 in the region just west of the city limits of Gulf Shores in Baldwin County, AL. The storm impacted the area as a Category 3 to Category 4 hurricane, producing record wind speeds, storm surges, and financial losses in both Baldwin County, AL, and Escambia County, FL. The storm directly impacted the 2001 Gulf Shores, AL, and 2003 Pensacola Beach, FL, Beach Restoration Projects as well as the 2003 West Beach Gulf Shores Emergency Beach Fill Project. These beach nourishment projects are monitored via annual beach profile surveys and rectified digital photography. The dramatic impacts of the hurricane to these beaches were documented using pre-storm data from February/May 2004 and post-storm data collected within two weeks of storm landfall. Data from the monitoring program allowed the communities to properly and quickly document sand losses in order to plan and pursue funding for restoration of the beaches. Post-storm surveys revealed typical volumetric losses of 75 to 175 m³/m from the beach fill construction berms. The shoreline receded as much as 16 m (average), while the upper elevations of the beaches experienced retreat of as much as 60 m. The storm left the beach profile in a very planar condition, exhibiting post-storm slopes of between 1:30 and 1:40 V. H. (typical). A portion of the sand eroded from the beach fill berms was deposited in significant overwash fans extending over 100 m landward in many areas. Similar volumes were deposited offshore.

The NOAA Coastal Storms Program was initiated to demonstrate the capability of NOAA to implement a program that cut-across all line offices within NOAA to create products and services for local users for a specific problem area. In this instance, a coastal storm theme is being used across three pilot regions for 3-year demonstration periods. The first pilot region, Northeast Florida, has just been successfully completed with stakeholder and partner workshops recently held in January 2005 in Jacksonville and Daytona Beach, FL. An important project within the Program has been Enhance Coastal Observations in which existing federal and state observing systems were enhanced to provide additional products and services for coastal storm observation and prediction. During the 2004 hurricane season, Hurricanes Jeanne and Frances affected the river basin with the eye of the storms making landfall to the south. Tide stations operating in the region successfully operated during the storm providing near-real time water level and storm surge information to local weather forecasters and to emergency responders. Post-storm analyses have been used to evaluate storm surge models and to show the nature of the progression of storm surge upstream.

The Coastal Storms Program (CSP) (formerly the Coastal Storms Initiative — CSI) is an interdisciplinary NOAA project designed to assist coastal communities in preparing for and mitigating the impacts of coastal storms. The first phase of this multifaceted program focused on the St. John's River region of northeast Florida. The hazards of greatest interest for this region are tropical storms, flooding, and ecological impacts. The second area of focus for CSP is in the Columbia River region of the Pacific Northwest. The primary concerns in this region are the prediction of Pacific storms, flooding and erosion, and fish habitat impacts. NOAA's National Weather Service (NWS) has taken a leading role in the improvement of wind, wave and flood predictions for these two pilot regions. In addition, preparations are underway to implement several new projects in a third pilot region in Southern California. While projects are underway in the Pacific Northwest pilot region, the primary focus of this paper will be on the efforts in the northeast Florida pilot, which is nearing completion. The exception to this is the high resolution wave modeling which had begun in the Pacific Northwest region before becoming involved with CSP.

As part of the Coastal Storms Program (CSP), an interdisciplinary NOAA project aimed at providing local communities with enhanced tools and resources to help mitigate the hazards of coastal storms, an experimental circulation model-based nowcast/forecast system of the St. Johns River, Florida has been implemented. The hydrodynamic model of the river and estuary makes nowcasts and forecasts of water levels, currents, salinity, and temperature and provides a means for the community to view the results. Two circulation model applications have been implemented and evaluated in the development stage of the nowcast/forecast system. The first of these model applications uses the Environmental Fluid Dynamics Code (EFDC; Hamrick, 1992a,b) to perform operational hourly nowcasts and 36-hour forecasts. This model application was originally developed by the St. Johns River Water Management District (SJRWMD) and calibrated for 1995–1998. The SJRWMD provided the calibrated model to NOAA's Coast Survey Development Laboratory (CSDL) for its implementation as a real-time nowcast-forecast system. The other model being examined for use in the St. Johns River is ELCIRC (Eulerian-Lagrangian CIRCulation model), a finite volume/finite difference baroclinic model for unstructured grids (Zhang et al., 2004).

The Federal Emergency Management Agency recently completed a new draft set of guidelines for coastal flood hazard analysis and mapping on the Pacific Coast of the United States. The project identified needs and prioritized improvements to coastal flood hazard analysis and mapping guidelines for the Atlantic, Gulf, and Pacific Coasts of the United States in Phase 1. In Phase 2, new draft guidelines were produced for use in FEMA's Map Modernization Plan for coastal flood hazard mapping in California, Oregon, and Washington.

The true number of rip current deaths in the United States (U.S.) is difficult to estimate because of data gathering limitations, but the United States Lifesaving Association (USLA) estimates that more than 100 persons a year die in rip current-related incidents in the U.S. This number is consistent with a study by Lushine (1992) that estimated 100 to 200 annual rip current deaths in the U.S. In certain states, it is felt that rip current deaths are more accurately known. A blueprint for reducing the number of people that die in rip currents in the U.S. will be described in five steps. The first step is providing an adequate number of well trained beach patrol at all surf beaches. The second step is education, both to the public and to the scientific community. The third step is improving the observation of rip currents and rip current channels. After improving observations the fourth step is improving forecasts and warnings. Finally, rip currents can likely be weakened or eliminated through physical modification of the surf zone. This paper discusses these steps and recommends procedures that would help accomplish the goal of reducing rip current deaths in the United States.

Many natural phenomena that occur along the coast are considered to be hazardous. These phenomena include tsunamis, large waves, rip currents, storms, earthquakes, erosion, bluff collapse, liquefaction, fires and others. Many of these events can be characterized through geographic components, areas of flooding and inundation, zones of liquefaction and subsidence, areas of rip currents, hot spots for beach erosion, tsunami run-up zones, bluff collapse areas and focused storm tracks. Some events have a temporal or seasonal component, such as El Niño storms or fires. The main approaches to hazards, regardless of timing or location, are, land use planning, engineering, monitoring and response. Santa Monica Bay in Los Angeles, California, was a pilot region for evaluating potential responses to geographically linked and temporally linked hazards. Hazard timelines were compiled to establish some of the temporal characteristics, showing El Niño and La Niña events, fires, storms and other disasters, as well as changes in population and rainfall. This combination of temporal and geographic information provides tools to develop hazard histories and provide scenarios for future risk. It also allows examination of the use and utility of various approaches to addressing hazards.

Laboratory measurements of a rip current system were obtained from a series of experiments in a directional wave basin using both in situ instruments and optical based methods. The in situ measurements include both water level and velocity measurements at key locations in the flow domain and Lagrangian drifters were recorded with digital video. Rip current pulsations were investigated for both monochromatic and bi-chromatic wave conditions. Although the rip current system had a response at the forced group frequency, there was significant energy at additional un-forced frequencies. The temporal relationship between rip mechanisms was also investigated for bi-chromatic wave conditions. A considerable lag exists between the peak of the pressure gradient forcing and the peak of the resulting current.

Rip currents are significant hazards that pose serious threats to surf zone swimmers and waders in all coastal regions. Rip currents form under specific conditions related to winds, waves, swell, tides, and bathymetry. These strong, narrow seaward flowing currents extend from close to the shoreline, through the surf zone, out past the line of breaking waves. Rip current strength and duration may vary dramatically depending on wave and swell parameters, and even the most experienced swimmers are in danger when they encounter a strong rip current. According to U.S. Lifesaving Association statistics, rip currents cause over 100 drowning fatalities each year, and 80% of all rescues on surf beaches nationwide are rip current related. Cooperative and coordinated efforts at many levels have combined to improve public education related to dangers associated with these surf zone currents. In many coastal regions, NOAA-National Weather Service issues a Surf Zone Forecast product that includes a 3-tiered Rip Current Outlook. Concurrently, NOAA-Sea Grant, NOAA-National Weather Service, and NOAA-National Ocean Service have developed a coordinated program and partnership to increase rip current awareness and improve communication between rip current research scientists and forecasters. These NOAA partnership programs exist at the local, regional, and national levels, working to coordinate applied research, outreach, and operational forecasts. Ultimately, the goals of the partnerships are to improve pubic safety and reduce the risk of rip current hazards.

Geographic Information System (GIS) and Remote Sensing techniques have been used in numerous natural-resource applications. Coastal Erosion studies accompanied by GIS and Remote Sensing play an important role in these activities. Purpose of this work is to study the erosion and deposition near the breakwaters for a stretch of 12.2 Km in Pondicherry coast, India by comparing the Satellite Imageries (PAN + LISS — June 2001 and November 2002) with Hydrographic Chart and Survey of India (SOI) Toposheet. Image Classification was performed on the Satellite Imageries in order classify the features such as Sandy Coast, Shallow Sea, Medium depth sea, deep sea .etc, Pattern Recognition, Spectral Classification, Textural Analysis and Change Detection are different forms of classification that were applied in this study to achieve the objectives mentioned above. With the aid of GIS and Remote Sensing techniques the change in the coastal geomorphology was clearly brought out. The new shoreline was captured from the imageries using overlay analysis techniques of GIS applications. Coastal erosion may have a direct impact on the virtual quality of the landscape. The erosional features and depositional features were identified and it provided a clue of equilibrium achievement between erosion and deposition. The result obtained from this work indicates a total erosion (8.0 Km) and deposition (4.2 Km) in the study area by comparing, Visual Interpretation and by applying GIS and Remote Sensing Techniques on SOI Toposheet, Hydrographic chart and Satellite Imageries is 309,059 Sq.m and 383,245 Sq.m.

Accurate estimates of longshore sediment transport are needed at several Carolina projects, in order to design shoreline protection devices for slowing erosion. Consequently, several communities have paid for deployment of wave gauges and current meters, and these data have been used in various analytical formulas to estimate sediment transport. Results have been compared between different formulas and between different project sites. Generally the results show that the more important tidal currents are, the less reliable is the traditional "wave-energy flux" macroscopic model for estimating sediment transport.

On an exposed sandy beach coastal impacts and sedimentation are important aspects in the optimization of a harbor layout. Hanstholm harbor on the West Coast of Denmark is an example of a very successful harbor located near a headland on an exposed coastline. The harbor is a fishery and ferry port originally designed by Professor Helge Lundgren and was built in the 1960s at a critical location with about 0.4 million m³/year net northward transport and a gross transport of around 1.5 million m³/year. The symmetrical and streamlined layout creates a smooth convergence of the flow past the harbor entrance and has in combination with vertical breakwaters resulted in acceptable sedimentation rates both updrift of the entrance and within the outer harbor. The sedimentation is localized in the outer harbor immediately inside the entrance, and a natural depth in the entrance area is about 9 m. The average yearly sedimentation in the harbor is 80,000 m³. The flow around Hanstholm harbor is mainly driven by meteorological forcing, variations in wind and pressure, and, to a less extent, by wave breaking. Tide is very limited in this area. An extension is planned on the western side of the existing harbor. The implications of the extension on the sedimentation in the outer harbor are the topic of the present paper.

This paper presents methods for assessing the coastal storm protection provided by an existing barrier beach and historic shore protection structure in Plymouth, Massachusetts. A multidisciplinary approach, utilizing both coastal geologic and engineering techniques, was employed to evaluate the ability of the existing beach to provide protection to Plymouth Harbor during significant coastal storm events. The results indicate the existing conditions are sufficiently stable during significant storm events to protect Plymouth Harbor.

One of the serious problems along the coastline of Tamilnadu in the Southwest of India (from 8° 05'30"N and 77°26'30"E to 8°16'N and 77°08'E) of length of about 60 Km has been continuous erosion. The acceleration of erosion is particularly during the Southwest monsoon that is during May to September. From the past data collection, it is estimated that the erosion rate is of the order of about 0.4 m/year and landmass of about 440 hectares along the coast is affected by erosion over the past 11 years. In order to protect the coast from erosion, a seawall was contemplated as a possible coastal protective measure considering the environmental conditions. Poly propylene geotextile fabric has been placed between the existing soil bed and the base layer to act as a filter media. The seawall is proposed for a length of about 10 Km in 28 different villages along the coast, which were severely affected. The sea bed at certain stretches consists of a number of outcrops and the same time the littoral drift has been quite active and its net direction is towards East. In order to handle the erosion problem, in addition to the seawall as stated above, a groin field was designed and executed. The presence of the groin field lead to the trapping of sediment transport resulting in the shoreline advancement into the sea. As the fishing community wanted the beach that has been built up in between the groins to be used as their boat landing facilities, a few of the groin were bent normal to the predominant wave direction thereby serving as both shore protection measure as well as boat landing facility. The details of the different layers, laying of the geotextile and gabion boxes along with the placing of the armour layers for the seawalls and the design and placing of armour units for groins are discussed in paper.

Duxbury Beach is a 5.5 mile long barrier beach system owned by Duxbury Beach Reservation. The barrier beach protects the landward harbors and shorefronts of the Towns of Duxbury, Kingston and Plymouth, Massachusetts and is the only land access to the isolated communities of Gurnet and Saquish in the Town of Plymouth. A critical aspect of the storm protection function of Duxbury Beach is the "sacrificial dune" which was constructed in 1992 after the October 1991 "No Name" storm (also called the "Halloween nor'easter"). As a result of a Presidential declaration of disaster, the Federal Emergency Management Agency (FEMA) concluded that the very low post-storm elevation of the barrier posed a significant public safety concern and urged the Duxbury Beach Reservation to take immediate action to restore the barrier and raise the dune elevation. After consultation with the U.S. Army Corps of Engineers (USACE), FEMA, based on its regulations, recommended that a sacrificial dune consisting of sand should be constructed to a consistent elevation of 16 feet NGVD (National Geodetic Vertical Datum). This is the peak elevation that would be reached during a hypothetical "5-year storm" (an event predicted to occur, on average, once every five years), which includes wave run-up. Following its construction, winter storms eroded and overwashed some of the sacrificial dune; however, most sand from that dune is believed to be contained within the Duxbury Beach barrier system.

Located south of Boston, the Nantasket Beach Reservation has been a popular summer destination for city residents since the middle 1800's. The beach is backed by a 5,400-foot-long, World War I era concrete seawall that protects buildings and other public infrastructure against storm-driven waves. In recent years, the U.S. Army Corps (Corps) of Engineers and the Massachusetts Department of Conservation and Recreation (DCR) have been developing plans to rehabilitate the beach and seawall, which have suffered significant long-term erosion. In December 2003, two coastal storms paused damage and undermining to sections of the weakened seawall. A Corps analysis revealed a 2,000 linear foot section of the structure was unstable, and recommended immediate intervention to stabilize the wall until the permanent solution could be implemented. The DCR quickly posted the area, erected safety barriers, and implemented a monitoring program to detect imminent failure. The DCR also requested emergency declaration from state regulatory agencies to affect repairs before the 2004 beach season. This prompted coordination and intense dialogue between the Corps, DCR, Massachusetts Department of Environmental Protection (DEP), Office of Coastal Zone Management (CZM), and the representatives from the Town of Hull to evaluate alternatives for an acceptable short-term solution. Three primary alternatives considered to restore passive support and toe protection for the structure included: (1) seawall reconstruction, (2) a stone revetment and (3) a cobble berm. This paper will present the stability problem, discuss the alternatives considered, and explore the requirements of the various stakeholders in developing a consensus. The construction of the temporary solution (a stone revetment) in the summer of 2004 will also be presented.

Sand dunes can provide an effective barrier to coastal flooding and wave damage. High, continuous dunes protect against flooding. Dunes containing large volumes of sand protect against wave damage by contributing their sand to the littoral stream during periods of high water and large waves. The level of protection is thus related to the height and volume of the dune. Coastal dunes evolve naturally as vegetation grows and flourishes on the backbeach. Dune growth is also induced by the erection of sand fencing. When the level of protection is reduced by coastal storms, the backbeach area becomes vulnerable to damage by subsequent storms until the dune is rebuilt, either naturally or by man's intervention. Thus there is a need to be able to predict rates of dune growth in order to estimate their recovery following a storm. The rate of sand dune growth at the Wildwood Convention and Civic Center (WCCC) was predicted using historical wind data (wind rose) and the median sand diameter. The predicted values were judged to be too high and were subsequently adjusted downward based on a comparison of the beach sand size distributions with the dune sand distribution and on dune growth rates observed elsewhere. A dune monitoring program was established to measure growth rates as well as the evolution of plants growing on the dunes. Measured dune growth rates during the first 1½ years following dune planting and sand fence erection were close to the predicted rates for each of three dune reaches. In the following years, dune growth slowed, presumably since much of the sand fence was buried. Later, dune volume was augmented by sand excavated from the construction site. An improved model using hourly offshore wind data was subsequently used. This model gave a good prediction of the rate of dune growth rate as well as an estimate of the dune sand size distribution.

Since 1995, Walton County has been impacted by numerous storms with varying intensities, most recently Hurricane Ivan in September 2004. The beach and dune erosion associated with the passage of Hurricanes Erin and Opal in 1995 and Hurricanes Earl and Georges in 1998 have been well-documented by numerous authors (e.g. Foster et al., 2000, Taylor Engineering, 2003). The Florida Department of Environmental Protection (FDEP) conducted the most exhaustive studies utilizing the state's monitoring stations for pre- and post-storm comparisons. In 2002, Walton County began to collect in-house beach surveys at the same stations that the FDEP has maintained since the early 1970's. The impetus for the start of the in-house monitoring program was the need for scientific data to assist in the local decision making process. A benefit of the program has been to collect and analyze data in the wake of not only coastal disasters but also smaller storms that affect Walton County's beach and dune system. This paper will address cumulative impacts that smaller storms have on the recovery of the beach and dune systems by focusing on the period between Hurricane Georges in 1998 and Hurricane Ivan in 2004; and illustrate the magnitude of dry beach losses associated with Hurricane Ivan.

To predict coastal building damage that may be caused by flooding, waves and/or erosion, the U.S. Army Corps of Engineers conducts Federal shore protection studies. These studies require inventories of coastal structures. To complete the inventories, first-floor elevations must be determined for each structure in the inventory. The Corps' Wilmington District conducted a pilot study to determine the accuracy and speed of several different floor elevation survey techniques. The tests were designed to assist Corps districts in determining hurricane and storm erosion damages related to first floor structure elevations. The desired outcome was to identify a faster and more economical method than the conventional methods employed by the Corps, without compromising accuracy. The District commissioned McKim & Creed to perform the tests associated with this pilot study. The testing consisted of four parts. (1) a comparison of floor elevations using different survey methods for 54 buildings in Wrightsville Beach, North Carolina; (2) an evaluation of rangefinder error with distance; (3) an evaluation of rangefinder repeatability for different operators; and (4) an evaluation of the accuracy of GIS (Geographic Information System) road points provided by North Carolina State University's (NCSU) mapping lab. The results were compiled by Spencer Rogers of the North Carolina Sea Grant Extension Program.

According to the National Research Council (1990) publication Managing Coastal Erosion, some setback methodologies establish only one erosion setback distance or zone, while others require setbacks of sequential zones of supposed reducing hazard landwards. But the NRC (1990) recommended methodology that identified erosion zones for 10, 30 and 60 year retreat rates. An alternative methodology presented by Healy and Dean (2000) and Healy (2002) identifies a single setback distance based upon summation of the 4 independent factors of long term erosion (or accretion) rate, decadal duneline "cut and fill", sea level rise induced dune retreat, and a dune stability factor. The initial setback is then subjected to 3 tests for sufficiency of the reservoir of dune sand storage for the long term, storm surge and flooding elevation, and tsunami run-up elevation. Thus this approach incorporates coastal hazards of erosion, sea level rise, dune stability, storm surge and flooding, and tsunami run-up, but only indirectly includes hazard from wind (if loss of reservoir from the frontal dune therefore erodes more rapidly) for a 100 year planning horizon. In this way it largely fulfils the philosophy of The H. John. Heinz III Center (2000) publication The Hidden Costs of Coastal Hazards. Implications for Risk Assessment and Mitigation which states: "A holistic view of coastal hazards is missing from current practices". Likewise the State of Florida Coastal Construction Control Line (CCCL) identifies a single setback distance, but is restricted to hazard of surge and erosion cut in a severe storm. This paper argues the case that determination of an holistic or all embracing coastal hazard zone comprising a single setback distance, is superior to implementing sequential zones of reducing hazard in a coastal management context.

The Atlantic Coast of New York Erosion Monitoring Program (ACNYMP), initiated in 1995, collects information and data on beach changes and coastal processes along the 210-kilometer ocean shoreline of Long Island, New York. To date, the program has collected over 3,400 beach profile surveys at 426 locations and semi-annual aerial photo surveys of the entire shoreline. Data and information such as historical shorelines, topography, locations of structures, flood zone delineations, etc. from other coastal projects have also been compiled and digitized as part of this effort. The goal of the ACNYMP is to provide coastal managers, regulators, government officials and the public with information that will allow them to make better decisions regarding coastal erosion hazard management. To encourage use of these data, the project sponsors have developed a quasi GIS viewing software application, known as CoastalView. The software, distributed on CD-ROMs with the program data, allows the user to retrieve, view, and perform simple analyses of all the data on a personal computer. An integrated photo viewer module displays digitized orthogonal aerial photographs, allowing the user to simultaneously view multiple sequential aerial photographs both spatially and temporally. Similarly, multiple profiles can be displayed and manipulated using a special profile-viewing tool. In a separate but related effort, beach profiles were analyzed and characterized using up to 44 parameters per profile. These data are stored in a relational database that allows access and analysis by geographical reach or station(s). Presently, ACNYMP partners are working with NOAA's Coastal Service Center to develop a GIS-based web site to disseminate this information more efficiently to a wider audience.

Storm surges can be destructive to infrastructure (roads, buildings, utilities, etc.) on barrier islands and deadly to humans that make the mistake of attempting to ride out an extreme storm whose path approaches the island. One common approach for mitigating the potential catastrophic storm damage that might occur on a barrier island is through the use of soft structure protection (i.e. beach fill). Evidence of benefits accrued using beach fill for storm protection has been documented in a number of papers in the published literature (see for example, NAP (1995), Dean (2002)), but limited work exists to assess the level of protection afforded by beach fills occurring on barrier islands where adjacent inlets or passes have possible adverse effects on the performance of the fill. This paper is a preliminary investigation of varying planform responses of hypothetical beach fills on barrier islands. In the work presented, various barrier island boundary conditions are investigated with similar hypothesized project beach fills. The planform response of the fill to a given storm climatology is provided for comparison of level of protection offered. Performance results for a variety of similar fill placements when subject to a severe hypothetical storm are provided in figures, showing the importance of prior knowledge of barrier island boundary conditions when designing a beach fill for a given level of storm protection.

As a result of the combined impacts of long-term erosion and short-term storm-induced erosion, the North Carolina Department of Transportation (NCDOT) initiated a study to assess the vulnerability of an erosional hotspot along NC 12 on Ocracoke Island. The methodology involved computing long-term erosion rates and combining these rates with short-term storm-induced erosion to predict the probability that the highway will be threatened by erosion for a 15-year future time period. Vulnerability of the highway to both increased maintenance and damage was predicted for a range of events representing a range of return period frequencies. The U.S. Army Corps of Engineers' SBEACH and EST models were used to estimate storm-induced erosion based on a 100+ year historical record of storm events (hurricanes and nor'easters) which impacted the study area. The most recent work analyzed the vulnerability of the highway following Hurricane Isabel in September, 2003. This study concluded, that a major portion of the Ocracoke Island hotspot is immediately vulnerable to increased maintenance induced by a 2-yr erosion event and that approximately one-third of the hotspot is susceptible to damage from a 50-yr erosion event.

Five months of field measurements of waves, sediments, and velocities at a dredged spoil mound are analyzed to determine rate of bathymetric evolution and direction of net sediment transport. The site is near the Brunswick Harbor Entrance Channel in Georgia. The mound was placed to investigate the feasibility of providing material to nourish the downdrift beach on Jekyll Island. Four computational techniques are employed to describe the fate of the placed sediments. Results indicate that the channel steers the flows of water and sediments, with net transport of sediments primarily along the channel axis as they leave the mound. Placing the disposal area farther downdrift of the entrance channel might increase the likelihood of indirect nourishment of the downdrift beaches after disposal.

Barrier islands form a primary buffer from hurricanes and other storm events to inland areas. It is widely understood that vegetation plays a key role in the ability of these landforms to serve as storm buffers and to promote recovery from storm damage. However, until recently, there have been very few modeling tools to simulate the role of vegetation in these very dynamic systems. Such a model now exists that can simulate both the impacts of storm events on these islands and on adjacent inland areas, and the role of vegetation in maintaining the integrity of these islands. ECOS²T (Ecological Systems for a Sustainable Tomorrow) is a mechanistic ecosystem model that simulates both physical and biological processes at multiple scales over. time. This model was used to simulate storm damage on a hypothetical barrier island along the central Gulf Coast of Texas. The primary processes implemented include effects of wind and wave transport of sand across the island, effects of vegetative cover, and impacts of winter storms and fall hurricane events. Simulation runs project the potential damage to topography in different physical zones under different climatic scenarios. The results indicate unexpectedly complex interactions among wind and wave processes in different zones. Models such as ECOS²T which can implement multiple physical and biological processes, should be particularly valuable for coastal ecosystem planning to maximize protection from storm events and to develop restoration plans for these critical ecosystems.

A broad-scale Wetland Change Model has been developed to identify the vulnerability of coastal wetlands at the large-scale. The model provides a dynamic and integrated assessment of regional to global patterns of wetland loss, and a means of estimating the transitions between different vegetated wetland types and open water under a range of scenarios of sea-level rise and changes in accommodation space from human intervention. This paper discusses key concepts raised in the process of quantifying the vulnerability of coastal wetlands to forcing from sea-level rise.

In this paper a model is developed to predict economic losses and vulnerability of residential buildings to hurricanes. Hurricanes are the most costly natural hazard affecting residential construction in coastal areas. Average annual losses are approximately $5.0 billion. With the increasing growth in population along coastal areas, the potential economic losses may be even higher in the future, becoming a heavy burden on homeowners and the insurance industry. The model proposed in this paper includes two key ingredients. The first ingredient is the fragility of components and systems that are vital for maintaining the integrity of the building envelope, expressed as a conditional probability of component failure given a specific hurricane wind speed. The second ingredient is the conditional probability of contents damage following failure of key components of the building envelope. The results of this study can be used to supportinsurance underwriting policies, and to facilitate building practices and mitigation efforts to minimize hurricane disasters.

Changes in the social environment now indicate that electricity, no longer viewed as a pseudo luxury, is necessary for preservation and ease of life even in adverse conditions. Over the past twenty five years, six separate tropical storm systems with hurricane force winds have entered the state of Alabama. During the course of this period, a variety of changes have been made to stabilize the structural and electrical integrity of Alabama Power's transmission system with the anticipation of a storm system. New technologies in structural design, materials, and application have increased the efficiency of the transmission system while allowing greater resistance to storms and other environmental hazards. Restoration planning, preparation, and execution have evolved during this process as well, and refinement of these procedures continue to progress.

A new procedure to derive the distribution of peak pressure and wind load coefficients from individual sample records is presented. The procedure is applied to field data obtained from the experimental building at the Wind Engineering Research Field Laboratory. (WERFL) and to wind tunnel measurements on generic flat-roof models of similar geometry made at Clemson University and the University of Western Ontario (UWO). From the wind tunnel data, load coefficients based on variable tributary areas are compared with the provisions of the ASCE 7 Standard.

This paper presents research progress for a model currently under development to predict vulnerability of existing industrial structures to hurricanes and extreme winds. Utilizing a study of industry practices and design recommendations, a statistical distribution that models the design of existing facilities has been developed. This distribution was then converted into an expectation of damage in the form of a vulnerability function. A case study illustrates usage of this developed methodology for the heavily industrialized and hurricane-prone area of New Orleans, Louisiana. The case study is presented in GIS format, which augments physical and spatial understanding of the possible impacts that may occur due to industrial structural failure under extreme wind conditions.

Permanent foundations for manufactured housing are subject to local building codes and are typically designed by engineers. Since they are in accordance with building codes, they are detailed to resist forces beyond those required for the mobile home itself. A more common definition of a permanent foundation includes foundations that are designed in accordance with the Permanent Foundations Guide to Manufactured Housing. Although such foundations are not commonly found in practice, foundations constructed in accordance with this document are not atypical since FHA Title II insured financing is only available for proposed construction when it is erected on a site built permanent foundation that meets or exceeds applicable requirements in the Permanent Foundations Guide to Manufactured Housing (i.e., FHA Title II insured financing is not available to homes tied down using soil anchors). This paper presents the results of a structural analysis of a typical manufactured home of specified dimensions using both permanent foundations and traditional soil anchors. Limit states associated with the lateral, uplift, overturning, and sliding response are all considered.

The design and construction of hurricane-resistant construction has substantially evolved over the last 50 years. Early efforts included hurricane-specific building code standards in South Florida and North Carolina. Those were followed by development and gradual refinement of national standards and codes such as ASCE 7 and the International Building Code/International Residential Code. Along the way Congress created the National Flood Insurance Program (NFIP) that mapped flood hazards along hurricane-prone shorelines on a national basis and required local adoption of construction standards in exchange for the availability of nationally subsidized flood insurance. Post-storm building performance reports have been prepared by the National Research Council's Committee on Natural Disasters and later FEMA's post-storm Building Performance Assessment Teams. Advisory documents such as FEMA's Coastal Construction Manual (2000), now in its third edition, have been developed to identify construction weaknesses and offer voluntary guidance on how to build more storm-resistant buildings. Design guidelines and standards have gradually improved over time as a result of observed building performance during storms and improved science. However, Hurricane Isabel in 2003 offers an opportunity to observe recent steps backward in design improvements in North Carolina. This paper reports on coastal flood, wave and erosion damage, the most severe causes of damage in Isabel. Several causes of the backward trends are identified.

Hurricane Isabel made landfall at Ocracoke Island, North Carolina, at approximately 1:00 p.m. Eastern Daylight Time on September 18, 2003. The maximum sustained wind speed at the time of landfall was forecasted by the National Weather Service (NWS) National Hurricane Center (NHC) to be approximately 105 miles per hour (mph). The maximum storm surge was reported to be approximately 12 feet. The NWS classified the storm as a Category 2 hurricane on the Saffir-Simpson Scale at landfall.

Since before Roman times, harbor works and coastal structures have been designed around the world, many of which still stand today. These early designers did not have the benefit of the sophisticated analyses we can perform today. This was true even as recently as 50 years ago. With the formulation of complicated expressions for wave generation, structural stability, and functional performance, the design community has lost touch with the bases and reasons for designing in certain ways, as well as having a fundamental perception of the scale of solution associated with a particular setting. This paper applies reverse engineering techniques to modern design relations to rediscover the basic design truths. Common design techniques are also explored to illustrate what types of solutions work where, and why or why not.

The Cox Creek Dredged Material Containment Facility (DMCF) project is being constructed for the Maryland Port Administration (MPA) and will be, used for the placement of material dredged from Baltimore Harbor. Moffatt & Nichol (M&N) prepared a coastal engineering design for rehabilitation of the existing containment dikes to re-activate the facility. Design components included raising the height of the dikes, placing a stability berm to account for poor geotechnical conditions, and armor stone slope protection. The design process included evaluating various slopes and armor stone combinations to select an optimal configuration as regards initial construction versus long-term maintenance costs. M&N completed the design and prepared bid documents for construction that began in September 2002. M&N also performed the construction oversight for the project. The earthwork and armor stone for the dikes were completed at the end of August 2003. Beginning September 18; 2003 and ending September 20, 2003, the Mid-Atlantic region from North Carolina to Maryland was subject to high water levels and high wind speeds associated with Hurricane Isabel. The purpose of this paper is to present data obtained from recording stations around the Chesapeake Bay and evaluate the performance of the coastal engineering aspects of the Cox Creek DMCF project following this 100-year return period water level event.

Riparian and extensive industrial areas at rivers and tidal estuaries in many parts of the world have been protected against regular and extreme floods with a system of dikes and dams for centuries. In Germany approx. 32.000 km of river, estuary and coastal dikes have to be maintained and improved against water level rises and increase of flood events by climate changes. Detection of faulty reaches by local inspections is costly and often ineffective. During storm and flood events it is often impossible to approach endangered parts for quick analysis and prevention of dam breaks and bursts. Airborne remote sensing before and during events of storms and floods with special High Resolution Stereo Space Cameras together with infrared photographing and GPS and GIS supported surveys are used to assess potential positions of risk for dam or dike failures. To identify basic sets of fault imaging, e.g. specific vegetation from certain seepage configurations or construction methods, a laboratory dike has been erected at the University of Hannover. Images from airborne remote sensing are compared with controlled laboratory conditions and specific programs are under development for near real time dike failure and risk assessment.

In Germany and many other coasts in the world flood prone areas are protected by sea dikes. Generally, the design of such structures is still based on purely deterministic or quasi-deterministic approaches and is either based on the design water level superimposed by the maximum wave-run-up or on admissible wave overtopping rates under extreme storm surge conditions. Geotechnical failure modes of sea dikes are often disregarded and not properly accounted for in the design process. Analysis of failure modes of sea dikes in Germany has shown why failures of sea and river dikes have occurred in the past and how breaching of dikes develops. The key steps to predict dike breaching are therefore to (i) properly describe the hydrodynamic loading of dikes; (ii) to identify the initiation mechanisms such as erosion and impacts on the dike body; and (iii) to provide a suitable model to predict breaching. The paper will deal with a probabilistic model providing the overall failure probability of a coastal defence system in Germany and Denmark. For this purpose the breaching process of sea dikes is regarded as an essential failure mechanism. The paper will give a brief overview of developments which have been made in improving existing analytical models for dike breaching in sand dikes under constant overflow conditions. This approach is then extended towards wave overtopping conditions for clay covered sea dikes. The probabilistic model uses a detailed fault tree approach taking into account 25 failure mechanisms of sea dikes, including the time dependencies between some of them. Uncertainties of the parameters and their influence on the overall result will be discussed. Results of the model and application to a real case study are also presented.

Marina vulnerability and damage in hurricane prone areas now extends across a range of considerations including the marina facility, financial issues, insurance issues, permitting agency issues, along with the anxiety and strain on management and staff. These issues need to be put in perspective upon returning to the marina. The complexity of the decision process requires a regimented approach to address changing priorities and to keep focused on the important goals. In additional to the obvious physical damage, the marina owner/operator soon finds that external or regional factors cloud important decisions on what to do upon return after the storm. The marina owner's decisions, priorities, staff assignments and schedules on how to handle boat owners, contractors and insurers follow closely after the primary concerns for staff and client safety. While each marina is different, a generalized approach is suggested as a guide to assist owners in putting damage and repair issues in perspective. The author is a Professional Engineer in Charleston, South Carolina and conducted surveys of damage to marinas in the coastal areas of North and South Carolina and Puerto Rica after Hurricane Hugo. He has continued to study hurricane effects on marinas after Hurricanes Andrew, Fran, etc. He has participated in the evaluation, assessment and redesign of hurricane damaged marinas. This paper presents a programmed approach to evaluation of safety concerns, environmental permit concerns, dock and ancillary structures damage, boat damage, boat owner control, utilities, contractor selection, construction phasing, insurance and news media control while the damaged marina is trying to recover and rebuild.

Spills of oil or other hazardous chemicals that are caused by mishaps at sea may result in significant impacts on the marine environment and on the coastal communities that exploit these regions. Calamitous chemical (oil) spills as well as the chronic exposure of frequent small spills has a harmful impact on biota and economical issues. The threat of chemical (oil) pollution on vulnerable marine and coastal areas is of great concern of the responsible authorities and requires permanent, stand-by or temporary measures. Management and control of coastal pollution disasters requires knowledge and understanding of the dispersion and effects of such spills. Important parameters determining the chemical (oil) spill behaviour at sea are wind, waves, tidal motion, bathymetry, and the shape of the land-water boundary. Accurate hydrodynamic information is therefore essential for reliable predictions of the dispersion and fate of chemical pollutions. This holds especially in the vicinity of coastal structures such as long dams and harbour breakwaters where large scale horizontal vortices can be present. These horizontal turbulent motions have dimensions in the order of hundreds of meters and time-scales in the order of minutes. In the usual flow simulations in which the classical unsteady shallow water equations are numerically solved, these motions are not resolved. Therefore, a proper and advanced modelling technique such as HLES (Horizontal Large Eddy Simulation) is required that faithfully simulates the creation and evolution of eddies with horizontal dimensions significantly exceeding the water depth near coastal structures. In addition, high resolution curve-linear boundary fitted model grids are essential for an accurate representation of e.g. curved break water. Within this paper we will demonstrate the use of advanced hydrodynamic modelling techniques by considering various contingency chemical spill scenarios nearby the IJmuiden harbour in the Netherlands. For this, a high resolution model of the harbour geometry inclusive coastal structures and the adjacent Dutch coastal zone is defined to address the significance of hydrodynamic complexity. The results can provide valuable information to facilitate in policy planning and harbour management issues such as moving leaking ships in distress towards a place of refuge.

Twice in 2003, on separate occasions, fully laden oil tankers lightly grounded upon approaching the entrance channel to Whangarei Harbour and the Marsden Point oil refinery. The navigation channel has remained stable since the 1960s, due partly to the armouring created by an abundance of coarse (large and heavy) bivalve shells over much of the channel. Subsequent to the groundings hydrographic surveys indicated only minor potential accretion of ~ 20 cm on the outer channel. Fortuitously at the time of one tanker grounding a wave meter had been deployed adjacent to the oil refinery wharf. Analysis of that data is consistent with the idea that a possible explanation for one of the groundings was the combination of long period waves arriving at the coast and locally generated short period waves causing the vessel to both heave and pitch. Fortunately there was no leakage of oil on these occasions althoughone vessel had only a single skin hull which, had it cracked, could have resulted in a major spill disaster. As a result of these events the NZ Maritime Safety Authority has undertaken a review of navigation safety at all New Zealand ports.

Charleston, SC is a city rich in tradition, history, and culture. However, for design professionals, the city and its surrounding area create a design environment like no other. Structures in coastal South Carolina must be designed for earthquakes, hurricane generated wind forces, and flood loads, making this region one of the most challenging design environments in the United States. To make matters worse, most recently, the city's deep-sea port system has been tagged as a major threat location for possible terrorist attack. To illustrate how well integrated multi-hazard design procedures can be applied to both new and existing structures, this paper presents the manner by which the design of the new Daniel Island Elementary and Middle School and the retrofit and six-story addition to the Florence Regional Medical Center were performed to achieve structural optimization. The school utilizes special reinforced masonry shear wall systems with intricate detailing necessary for coastal flooding, seismic ground shaking, liquefaction potential, and hurricane generated out-of-plane wind forces. Although the existing hospital was designed to carry the six additional floors and the effects of code specified lateral loads, it was designed to the Standard Building Code. South Carolina has since adopted the International Building Code (ICC, 2002), which increases the seismic load two-to-three fold and requires significantly more detailing than anticipated during the design of the existing structure. The hospital retrofit and addition include significant structural upgrading such as steel plating of existing concrete shear walls and the addition of new steel framed towers at both ends of the existing building to resist torsion and part of the code specified lateral forces from the design earthquake.

Tsunami is considered as one of the most-important hazards in coastal areas. In the process of making tsunami hazard maps, it is necessary to estimate the seismic performance of breakwaters and sea walls, since the area of inundated backyard can be much influenced by the existence of these structures and the performance of sea walls as barriers against tsunami is dependent on the seismic stability of the structures. In order to establish a practical method for sea wall settlement evaluation, a set of parametric studies by an effective stress-based FEM has been conducted. Numerical results indicated that the soil strength combinations for backfill and foundation control not only the magnitude of deformation but also the deformation pattern. The numerical results obtained in the study enabled the settlement assessment based on geotechnical profile only, and it is possible to prioritize the numerous facilities along the coastline for seismic retrofit.

The damaging 1886 moment magnitude ~7 Charleston, South Carolina earthquake is indicative of the moderately likely earthquake activity along this portion of the Atlantic Coast. A recurrence of such an earthquake today would have serious consequences for the nation. The national seismic hazard maps produced by the U.S. Geological Survey (USGS) provide a picture of the levels of seismic hazard across the nation based on the best and most current scientific information. The USGS national maps were updated in 2002 and will become part of the International Codes in 2006. In the past decade, improvements have occurred in the scientific understanding of the nature and character of earthquake activity and expected ground motions in the central and eastern U.S. The paper summarizes the new knowledge of expected earthquake locations, magnitudes, recurrence, and ground-motion decay with distance. New estimates of peak ground acceleration and 0.2 s and 1.0 s spectral acceleration are compared with those displayed in the 1996 national maps. The 2002 maps show increased seismic hazard in much of the coastal plain of South Carolina, but a decrease in long period (1 s and greater) hazard by up to 20% at distances of over 50 km from the Charleston earthquake zone. Although the national maps do not account for the effects of local or regional sediments, deep coastal-plain sediments can significally alter expected ground shaking, particularly at long period motions where it can be 100% higher than the national maps.

The March 1964 Alaska tsunami caused major damage in Alaska and also impacted the west coast of North America. Crescent City, 3000 km away from the source region, suffered the greatest damage outside Alaska. At least four observable waves hit,the area and peak tsunami run-up was 6.7 m relative to Mean Lower Low Water (MLLW). Thirty blocks of the downtown and harbor areas were inundated and nearly 300 homes and businesses damaged or destroyed. We reexamine pre- and post-tsunami air photos, damage assessments and personal accounts to describe tsunami flow characteristics, inundation and structural damage. Eyewitnesses generally described the incoming water as a gentle flow with water elevation increasing at the rate of about 0.3 meters/minute. The peak water elevation in the developed parts of the City reached about 3 meters above the land surface. In areas where the water depth was one meter or greater, the most common cause of structural damage was floating wooden houses off foundations. Other structures were damaged by the impact of debris and moving structures, and/or walls buckling from internal water pressure after the water receded. Fires ignited gasoline tanks and spread to neighboring structures. Most of the buildings within the inundation zone were subsequently demolished through the Crescent City Redevelopment Project. In the forty years since the tsunami, Crescent City has established a siren-based tsunami warning system and developed tsunami evacuation maps, posted signs along evacuation routes and is the only city in California currently designated "Tsunami Ready" by the National Weather Service's TsunamiReady program. However offsetting these mitigation efforts is the increased exposure caused by new commercial development within the 1964 inundation zone and recognition of the Cascadia subduction zone as a source of significantly larger tsunamis than the 1964 event.

Large parts of the coastal hinterlands at the German North Sea coast are endangered from flooding during storm surges. In order to improve hazard mitigation the method of risk analysis is introduced in the strategic planning of coastal defenses. Risk analysis comprises the calculation of the failure probability of different coastal defense structures, especially of sea dikes, and the determination of the consequences in case of flooding. The basic principles are outlined and exemplified in a climate impact assessment studying the effect of rising sea levels and intensifying winds on the risks related to storm surges. To cope with an increase of risk different strategies, like strengthening of existing coastal defense structures and introducing additional coastal defenses, are developed and evaluated with respect to their efficiency in reducing risk.

Maryland's diverse coastline is particularly vulnerable to rising sea level. In the Mid Atlantic, sea level has risen approximately one foot in the last century and due to a combination of climate change and regional land subsidence, is expected to rise another 2 to 3 feet by the year 2100. A rise of such magnitude, nearly twice global predictions, will undoubtedly exacerbate coastal flooding, increase shoreline erosion and result in the slow but steady submergence of tidal wetlands and other low-lying lands. The Maryland Department of Natural Resources has directed substantial efforts towards analyzing and addressing the impact of rising sea levels along the State's coastline. Activities have largely centered on the incorporation of sea level rise issues into coastal planning and policy initiatives, technology, data and research support, and public outreach. Summaries of these efforts are provided along with a discussion of the lessons learned as a result. Lessons learned include the need to: (1) target ongoing coastal management initiatives; (2) engage and support local governments; (3) use conservative estimates of sea level rise; and, (4) avoid complexity when designing and translating sea level rise research efforts. These lessons are helping to guide Maryland's current sea level rise planning efforts and may be prove valuable to other regions of the country that are facing similar troubles due to sea level rise.

Bangladesh is one of the world's poorest countries and is prone to a multitude of climate-related impacts such as floods, droughts, tropical cyclones and storm surges. The vulnerability of people living in the coastal zone has been demonstrated in numerous studies and is emphasised in the recent Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, 2001). The subsiding coastal zone in Bangladesh is particularly vulnerable as it is affected by more than twice the mean predicted global rate of sea-level rise. The consequences are saltwater intrusion into surface and groundwater systems, drainage congestion and water logging, and changes in morphodynamic processes resulting in increased riverbank erosion. In addition, sea-level rise has the potential to make cyclones and coastal inundation even more damaging than they are today.

The hinterland on the North Sea coast of Germany is protected by various defence elements. The most common protection element is the dike. Its design is regulated in the German code EAK (Ausschuss für Küstenschutzwerke, 2002). The design concept considers the vulnerability of a coastal hinterland in case of failure of the protection system, e.g. dike breaching, only very limited, i.e. by additional safety margins. An estimation respectively an exact calculation of the probability of failure is not part of today's deterministic approach. Within a probabilistic design the calculation of the failure probability is the basis to include the vulnerability of the hinternland into the design process of dikes. The integrated design is typically based on the definition of the risk of inundation (Plate and Duckstein, 1988). The risk is defined as risk = probability of failure x loss in case of failure. The loss determines the part of all values in the hinterland being destroyed in case of failure of the protection system. It equals the product of the total property and a damage factor being a function of the inundation characteristics: loss = total property x damage factor. A realisation of a risk analysis with special focus on geographical information systems GIS is outlined in this paper. The basics of the GI systems are described in chapter 2, while chapter 3 describes exemplarily the integration of the risk analysis into a GIS for the coastal regions between Wilhelmshaven and Bremerhaven in Germany.

Inadequate construction setbacks over the last century on the Hawaiian island of Maui have led to a heavy reliance on shoreline armoring for structures now facing erosion crises. Along 56 miles of sandy shoreline, over 370 shore protection structures, such as seawalls, revetments and groins, have been built, nearly two thirds of which have been identified in an unpublished study as likely having a negative impact on the adjacent sandy beach. In November 2003, Maui County set a precedent for shoreline protection among the counties of Hawaii by being the first to adopt erosion rate-based construction setback rules. The process of producing erosion rate data and creating and adopting the new setback rules took over 5 years. A significant amount of input was received from the public through an advisory committee, public workshops and public hearings. Following the adoption of die new rules, planning and permitting situations have arisen that have revealed limitations in the rules. These issues are currently being addressed on a case-by case basis, but it is likely that further amendments will be necessary.

The NOAA Pacific Services Center (PSC) works through the NOAA Coastal Services Center (CSC) to develop and deliver products and services that promote sustainable and resilient coastal communities in the State of Hawaii, Territories of American Samoa and Guam, and the Commonwealth of the Northern Mariana Islands. One of the needs identified as being of critical importance to the Pacific Islands is planning for and responding to the economic, social, and environmental risks due to natural hazards. The development of locally customized, regionally replicable Geographic Information System (GIS) and other information technology (IT)-based tools to enable better, faster, and less costly decision making is a central part of efforts being carried out to meet this need. Specifically, PSC and CSC have developed a two-part ArcIMS-based tool to support natural hazards risk management planning and permitting. The first part of this tool follows from the Risk and Vulnerability Assessment Tool (RVAT) and the Hazard Locator Tool developed by the CSC as part of the Coastal Storms Initiative (CSI). This "point and click" tool is targeted at permitting-related decision-making by allowing the user to determine multi-hazard risk for a specific location. This location specific information is provided to the user in the form of a text summary, as well as a map. The second part of this tool is targeted at community/village-scale planning-related decision-making. This "stoplight" tool allows the user to determine an area's multi-hazard vulnerability as expressed through a combination of intrinsic, anthropogenic, and historic loss vulnerability indices for each hazard. This tool also provides the user with a summary of the area specific information in both text and map formats. A secondary goal of the tool identified above is to increase awareness and education about the hazards that could potentially affect a community/village and actions that can be taken to help lessen the multi-faceted impact of these events. This is accomplished, in part, by providing access to additional supporting information via links on the Web site on which the tool resides.

Floodplain management regulations, in conjunction with other local land-use requirements and building codes, are intended to minimize damage as a result of flooding disasters. However, merely meeting these minimum requirements does not guarantee protection from storm damages, nor does it prevent unsustainable development from occurring. Management activities that focus on mitigating a single, short-term hazard can result in structures and critical facilities that are built only to withstand the hazards as they are identified today, with no easy way to accommodate an increased risk of damage in the coming decades. Floodplain managers recently developed the "No Adverse Impact" (NAI) initiative to encourage development-related best practices that "do no harm," either to proposed development, other existing development, or future development. Applying NAI principles to the coastal zone requires recognition of the multiple hazards that occur over multiple temporal and spatial scales (e.g., storm surge and wind hazards during a hurricane versus relative sea-level rise or long-term erosion). Although the most appropriate solutions will vary with geography and physical processes, recommended coastal NAI practices include: application of V Zone building standards in coastal A Zones (as shown on flood hazard maps); limiting the use of fill to elevate buildings in coastal A Zones; restoration of dunes and dune vegetation; and community education and outreach. Most of these practices can simultaneously mitigate the impacts of multiple coastal hazards, and could greatly assist communities in developing (or redeveloping) the coast in a sustainable and damage-resistant manner.

Coastal problems, such as erosion, exist all over the world. Technology has developed many tools and techniques to defend against hazards like erosion, but these things continue to be a problem. Part of the problem is a lack of awareness that the problem exists. The purpose of this paper is to present examples of coastal problems to increase awareness of the issues and educate with new examples of the problems. Iceland has a great diversity of coastal problems; including erosion, volcanic activity, seismic activity, glacial activity, catastrophic flooding, pollution, and climate change.

The Hawaii Coastal Hazard Mitigation Guidebook builds on and complements the Federal Emergency Management Agency's Coastal Construction Manual (FEMA, 2002) with special emphasis on the proper siting of coastal structures. Although the major thrust is on coastal hazards, the strategies presented are applicable to any natural hazard in which siting is critical, whether it is in Hawaii or elsewhere. Thus, the Guidebook discusses the relative geographic risk from erosion, wave inundation, flooding, wind damage, hurricanes, tsunamis, as well as other natural hazards such as lava and earthquakes. Four major hazard zones are identified. The Guidebook then divides the development process into eight stages and discusses mitigation measures that are appropriate at that stage given scientific, legal, economic and fairness factors. Strategies are presented to help implementation of the mitigation measures based on the utilization of planning information, guidance, industry standards and policy.

The Hawaii Coastal Zone Management Program is a multi-objective program covering broad areas of ocean and coastal resource management and public participation. The Program works collaboratively with other agencies and groups in the coastal hazard arena. The joining of agencies and individuals, and the knowledge and resources that accompany them, has resulted in wiser use of those resources and more rapid progress in reaching common goals and objectives. This paper explores the workings of three Hawaii-based hazard mitigation partnerships and the role of the Hawaii Coastal Zone Management Program in each of them.

From 31 January to 1 February 1953, a North Sea storm surge devastated coastal areas of the United Kingdom, Belgium, and the Netherlands. Apart from enormous economic damage and severe societal disruption, over 2,000 people died across the three countries. This paper discusses the available data on loss of life in these three countries and examines the application of these data for loss of life estimations and general flood management practices.

Over the last five years, the Department's of Transportation in 12 coastal states threatened by hurricanes have developed plans for the implementation of contraflow traffic operations on freeways during evacuations. Contraflow involves the use of one or more inbound travel lanes for the movement of traffic in the outbound direction. It is both a logical and cost effective strategy because evacuation traffic can be loaded into underutilized inbound lanes, thereby significantly increasing outbound capacity without the need to construct additional lanes. This paper summarizes the results of two recent studies to evaluate the implications of contraflow evacuations on freeways. The research focused on what are widely regarded to be the most critical locations of contraflow segments, the initiation and termination points. The termini configurations are important because they effectively dictate the capacity of these segments because they control how many vehicles can get in and out. In the research, traffic simulation models were developed to simulate the operation of planned configurations under varying levels of traffic demand to assess their operating characteristics. The results showed that many of the current designs of the initiation and termination points will likely restrict the ability of these segments to be used to their maximum effectiveness. Another key finding was the extent to which the spatial and/or temporal spreading of traffic demand can yield significant benefits to the overall effectiveness of contraflow freeway evacuations. It is hoped that with an increased awareness of these issues, these findings can be used to enhance the effectiveness of existing evacuation plans.

The International Joint Commission (IJC) is presently re-evaluating the operational procedures for the Moses-Saunders Power Dam in Massena, New York, which controls the water levels of Lake Ontario and the flows of the St. Lawrence River. The weekly discharge rates at the dam range from 5,000 to 10,000 cubic meters per second and are regulated by a series of rules developed under the Boundary Waters Treaty of 1909 between the US and Canada. The current regulation plan is 1958D. New plans presently under consideration require complete impact evaluations for the system stakeholders that are sensitive to water level fluctuations, such as riparian property owners, the natural environment, and hydroelectric power generation. Baird & Associates was retained by the Buffalo District US ACE to evaluate the impacts of water levels for the alternative regulation plans under consideration on flooding and erosion hazards for riparian property. Refer to the companion paper for the discussion on erosion (Nairn and Zuzek). The study area included over 4,000 km of river and lake shoreline and 21,000 riparian properties. Given the vast geographic extent of the study area, complexity of the analysis, and fast-track schedule, the utilization of GIS technology and custom software applications was critical to the successful completion of the project. Baird relied on the functionality in the Flood and Erosion Prediction System (FEPS), which links GIS to engineering models and a relational database, to complete the analysis on budget and on schedule.

The shoreline of Lake Ontario has been exposed to erosion and sedimentation processes since the retreat of the Wisconsin Glaciation, approximately 12,000 YBP. In modern times, these processes continue to shape the shoreline along with human influences, such as shoreline protection, harbor construction, dredging and beach nourishment. Water levels play a key role in how we manage coastal hazards along developed shorelines. For example, during periods of high lake levels shoreline erosion rates accelerate beyond the long term background rate and riparian land owners are often faced with the economic burden or building shoreline protection to save their house. During low lake levels, navigation is often a problem that requires intervention in the form of channel dredging. The International Joint Commission (IJC) is presently re-evaluating the operational procedures for the Moses-Saunders Power Dam in Massena, New York, which controls the water levels of Lake Ontario and the flows of the St. Lawrence River. The weekly discharge rates at the dam range from 5,000 to 10,000 cubic meters per second and are regulated by a series of rules developed under the Boundary Waters Treaty of 1909 between the United States and Canada. The current regulation plan is 1958D. New plans presently under consideration require complete impact evaluations for the system stakeholders that are sensitive to water level fluctuations, such as riparian property owners, the natural environment, recreational boating, commercial navigation and hydro electric power generation. Baird & Associates were retained by the Buffalo District USACE to evaluate the impacts of water levels generate by new plans on erosion and flooding hazards for riparian property. Refer to Zuzek and Nairn (these proceedings) for a discussion of the flooding methodology. The study area included over 4,000 km of river and lake shoreline and 21,000 riparian properties. Baird has been involved in studies of shoreline erosion on the Great Lakes for over 20 years and this knowledge was recently summarized in a Chapter 5 Part III of the Coastal Engineering Manual prepared by the USACE. In addition, the development of the COSMOS model (Nairn and Southgate, 1993), which is capable of modeling erosion processes for the wide range of shore types (i.e. geology) found along the shores of the Great Lakes, provided the necessary fine scale modeling tool. Development of the Flood and Erosion Prediction System (FEPS) began during the Lake Michigan Potential Damages in the late 1990s.. The FEPS links GIS technology, engineering models such as COSMOS, and custom software applications. At a local scale, there was sufficient knowledge, experience and capabilities to predict shoreline response for alternative regulation plans developed by the IJC. However, the principal challenge was the application of this skill to over 4,000 km of shoreline at a very fine resolution (i.e. individual property parcels). In addition, the individuals who are developing new regulation plans required an automated procedure where a 101 year water level hydrograph is entered in the model, the physics of erosion is predicted, and economic damages are exported. To accomplish these goals addition functionality was required in the FEPS, such as a Relational Database Module to store information for the economic analysis. The key components of the investigation, along with samples of the predictive capabilities of the FEPS, will be summarized.

The need for protection of Coney Island from major storm surges spawned this study and gave rise to a collection of projects which could benefit from the proposed breakwater/causeway. From an engineering point of view there appears to be no mammoth problem to deter its implementation. Although the cost would be large, its multiple benefits must be weighed in the decision. Ultimately, as with most projects of this scope, the decision will probably be based more on political factors than on economic ones.

This paper is an extension of previous work (Magoon et al., 2004) wherein the authors offered a preliminary estimate of the sediment losses and the value of sediment losses from engineered interferences that impact the sediment supply along the Pacific Coastline of California, Oregon and Washington. Based on an array of secondary sources, in the Pacific states nearly 28 million cubic meters of material is lost annually to engineered interferences. Preliminary estimates of cumulative losses since 1950 total 1.4 billion cubic meters. In this paper, we examine the activities (that produce goods and services) causing these losses to the coastline and estimate the increase in cost of the good or service to avoid or mitigate the sediment loss. The engineered interferences considered, in order of importance are (1) sand and gravel mining, (2) dams and flow regulation, (3) subsidence related to fluid extraction, (4) dredging, (5) debris basins, (6) harbor deepening and (7) seawalls and other armoring. This paper examines sand and gravel mining and dams and flow regulation that together result in about 95% of the sediment losses. Corresponding cost increases to mitigate and/or reduce the sediment losses are examined for goods and services including sand and gravel, flood control, hydroelectric power, and water supply.