World Environmental and Water Resources Congress 2017: Watershed Management, Irrigation and Drainage, and Water Resources Planning and Management

This study investigated the extent of urbanization that might result from the implementation of a project called Project Canal Istanbul (PCI) using the SLEUTH urban growth model and assessed its impact on the hydrological response of Ayamama watershed using the HEC-1 hydrological modelling tool. SLEUTH was run under two scenarios: Current scenario (without PCI) and PCI Scenario (with the implementation of PCI). The prediction results showed that the urban extent of Ayamama watershed would reach 44 km² and 63 km² under the current and PCI scenarios, respectively, by 2050. The HEC-1 simulation results under the indicated urban extents and various rainfall amounts showed that the urban extent of the watershed under the PCI scenario would resulted in a significant increase in the peak discharge. Such a change may increase the risk of flooding and, therefore, appropriate actions that can reduce such a risk need to be considered before the implementation of PCI.

A useful hydrologic model reproduces basin hydrology and, provided targeted analysis, can inform a variety of water resource applications including flood risk management, flood forecasting, water supply, climate change, and water quality/sedimentation. As part of a larger reservoir reoperation study, a continuous simulation model of the Russian River Watershed in California, USA, was developed using the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS). Modelling focused on quantifying soil moisture and reproducing observed runoff through the wet/dry annual cycles of a 60 year simulation period, 1950 through 2010. The Russian River model simulated soil moisture using the soil moisture accounting (SMA) and deficit and constant loss methods coupled with the Penman-Monteith evapotranspiration method. Model calibration focused on reproducing observed basin runoff signatures including flood flow-frequency, seasonal runoff, and the runoff hydrograph. Performance measures quantified the model’s ability to reproduce observations and proved the model useful for subsequent reservoir reoperation analyses. This paper presents model development using HEC-HMS for continuous simulation of the Russian River Watershed; steps include forming precipitation and evapotranspiration boundary conditions, initializing and calibrating model parameters, and evaluating results, to arrive at a final useful model.

Population growth and urbanization are major threats to the sustainability of watersheds. The increase of impervious areas in watersheds results in more surface runoff generation during storm events, which can increase risk of flooding, and also reduce the recharge of aquifers and base flow of rivers. Consequently, accurate representation of land cover changes in watersheds is very important to adequately identify its impacts on water bodies. Most of event-based and continuous simulation hydrologic models consider land cover as a static parameter. However, in fact, the land use change is dynamic in urban areas and can have profound impacts in the main hydrologic processes. This study proposes the use of a cellular automata (CA) model to represent land use change and its interactions with the hydrologic cycle. The CA land use change model represents urban sprawl by calculating the likelihood of changing the state of an undeveloped cell to urban based on spatial factors such as number of developed neighbors, distance to roads and central areas. The CA model is connected to the soil and water assessment tool (SWAT) model, to assess impacts of land use change on stream flow and also identify how dynamic land use change improve watershed simulations. This method was applied in an urban watershed in San Antonio, TX, which is experiencing one of the highest rates of population growth in the U.S. and faces tremendous stormwater and drought challenges.

In this study, GR4J and Sacramento soil moisture accounting model performance and parameters response to 14 different PE inputs is evaluated in a sample of two watersheds located in South Korea. The 14 PE inputs selected to assess the response of the two watershed models for better streamflow simulations varies from simple to more data demanding models. The result of both models in the tested watersheds was insensitive to different PE inputs, due to the ability of Shuffled Complex Evolution–University of Arizona algorithm to adapt and optimize parameters for each PE inputs in the calibration process. The parameter of both models responsible for changing the PE to actual evapotranspiration are significantly affected by the different PE inputs but the remaining parameters are relatively stable. The result of the study will provide some level of confidence for modelers to work with temperature based PE models, due to its competent efficiency as that of data demanding and complex models for areas with limited climate data.

Due to the hydrologic uncertainty in determining the parameters associated with alluvial fan formation surface, the Federal Emergency Management Agency (FEMA) has developed a stochastic approach, FAN (1990), to assess flood hazard for flood insurance purpose and to estimate flow depth for floodplain delineation. But this FEMA approach does not clearly address the fan shape watershed hydrologic analysis and its peak flow prediction to satisfy mass conservation and continuity principle. The geometric transformation procedure described in this paper offers a geometric conversion to transform diverging fan shape watershed into a virtual KW rectangular plane for surface runoff prediction. Using this geometric conversion procedure as guidance, the simulation results are comparing to laboratory records to prove to be a singled value relationship. The results presented in this paper produces a good agreement among the laboratory record, predicted hydrograph and the theoretical solution. The approach outlined in this paper presents a significant improvement to the current practice on alluvial fan hydrology.

Wetlands are a significant component of the Kissimmee-Okeechobee-Everglades ecosystem. This paper presents the hydrologic response (unit hydrograph) of the East Lake Toho Sub-Basin, a wetland area with significant development, in the Upper Kissimmee Basin in South Florida. The study is part of the effort of establishing a hydrological forecast system for the Upper Kissimmee Basin and building a decision-making system to support water management operations. The results show that the peak of the derived unit hydrograph from large rain events in the most recent 15 years data is significantly lower than that developed by the USACE in the 1950s. The finding is a puzzle, because the peak value of the unit hydrograph is expected to be higher given significant development in the area in the past decades. The reasons need further investigation.

The Ventura County Watershed Protection District (VCWPD) maintains and operates more than 50 Debris and Detention Basins throughout the County, in southern California. Many of these basins have been built decades ago by other agencies like natural resources conservation service (NRSC) to help with flood protection and debris flows during intense storms. These basins were later transferred to VCWPD for long term operation and maintenance. With land use changes over the past 60 years, some of these basins do not meet their original purpose now and with limited funds available for upkeep and maintenance of flood control facilities, VCWPD is looking for options to reduce maintenance costs. There is also a need to evaluate whether these basins are necessary, and if so should the public funds be spent to protect few surrounding property owners. In light of these questions, a complete study of a few of these basins have been conducted by the VCWPD to address these questions and find out whether or not some of these basins can be abandoned, retrofitted for multi-purpose use, and/or transferred to surrounding property owners for maintenance and upkeep. As part of these studies cost-benefit analysis were also conducted to guide the management in the decision making process. In this paper we will discuss a couple studies conducted by the VCWPD that includes an overall survey of the functionality of the basins, hydrologic and hydraulic study/modeling to evaluate the flood control benefits of the basins, alternative evaluations for multi-purpose use of the basins such as groundwater recharge to augment water supply, and an overall cost-benefit analysis of a couple basins to guide decision making with respect to the future of the basins.

Current U.S. Army Corps of Engineers (USACE) guidance requires the development of a “hydrologic hazard curve” when evaluating the hydrologic risk for dams and levees. The hydrologic hazard curve provides magnitudes and probabilities for the entire range of peak flows, flow durations, and stages. These variables are used when assessing potential failure modes as part of risk assessments. For instance, the probability of failure is often conditional on the magnitude of stage. Due to the age of most USACE projects, there is usually not enough observed data to directly estimate a stage-frequency relationship for relatively remote annual chances of exceedance (ACE). In order to provide adequate information for use in risk analyses, extrapolation of stage-frequency curves to remote ACE is often needed. Balanced hydrographs can be used as a means to inform pool stage-frequency curves (dams) and river stage-frequency curves (levees) for remote ACE. New tools are under development at the Hydrologic Engineering Center (HEC) that can better estimate stage-frequency relationships and hydrologic hazard curves. Version 2.1 of the Statistical Software Package (HEC-SSP) contains features that can fit the Log Pearson Type III distribution to annual maximum flows using Bulletin 17C procedures as well as quickly develop multiple balanced hydrographs. Version 4.2 of the Hydrologic Modeling System (HEC-HMS) contains features that can then efficiently route these balanced hydrographs. In this way, more informative stage-frequency relationships can be developed for use in dam and levee risk analyses.

El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) are two of the most important climate indices that influence the western U.S. hydrology significantly. This study evaluated how these two indices have influenced California streamflow over the years and determined their correlation at multiple time-scales. Data were obtained from 14 unimpaired streamflow stations of California for a study period of 63 years (i.e., 1951 to 2013). The concept of continuous wavelet transform was applied to observe the variance in each time-series at multiple time-scale bands over the years. The correlation was found to be higher in the latter half of the study period. ENSO showed a higher correlation with California streamflow compared to PDO across the study period. The results of this study can be of assistance in determining the relationship between Pacific SST fluctuation and California streamflow. The findings may help understand the recent California drought as well.

Floods are one of the major natural disasters in Indonesia. Jakarta experienced several floods almost every year such as 2002, 2007, 2013, 2014, and 2015. In this study, a physically based rainfall-runoff and flood inundation model was developed in order to understand the flood inundation mechanism in Jakarta. A sensitivity analysis of the model was conducted using different model datasets. As the result of analysis, it was found that there are no significant differences between simulation results using 90 m and 5 m DEM resolutions because these finer DEMs were obtained from satellite images and show no big differences in accuracy. We concluded that the radar rainfall and land use/cover conditions are playing important roles in the model in order to reproduce flood inundation situation precisely in Jakarta.

The aim of this study is to evaluate the filtering techniques which can remove the noise involved in the time series. We used the radar rainfall series for evaluating the noise reduction capabilities of LF and KF. In this case, it was difficult to distinguish which filtering technique is better way for noise reduction when the typical statistics such as correlation coefficient and standard error were used. However, when the attractor and the BDS statistic were used for evaluating LF and KF, we could clearly identify that KF is better than LF. In this study, we have shown that the attractor and the BDS statistic can be applied for investigating the characteristics of the noisy series such as noise added chaotic series and radar rainfall.

Water is fundamental to life on Earth and socio-economic development. However, global water resources are threatened by growing demands and climate change. Managing competing demands for water in various sectors is challenging, especially for complex river basins. To address the issue of water allocation and to maximize the use of limited water supply, this study used simulation and optimization techniques to explore possible ways forward improving water system management. The modeling framework is demonstrated through a case study of the Lower Chao Phraya River Basin with multi-reservoir systems operations. A monthly simulation and optimization models were developed using IBM ILOG CPLEX Optimization Studio software. Optimal reservoir releases were determined by linear programing with an objective function to minimize water deficit. In this study, water management could be improved by prioritizing water allocation to crucial sectors, allowing dynamic reservoir release pattern to serve socio-economic development, and offering the assessment of various management alternatives. The proposed framework was useful for managing water supply and joint reservoir operations system.

This paper investigates the presence of monotonic changes in hydrologic extreme indices in the Sao Francisco River Basin, which plays a strategic role in Brazil. The study focuses on the following indices: number of consecutive dry (wet) days (CDD/CWD), number of days with precipitation greater than a given value (Rx), number of days with precipitation (Ndays), simple daily intensity index (SDII), annual maximum series of both precipitation (Rxt) and flows (Qmax), and annual 7-day averaged minimum flows (Qmin). The Mann-Kendall test in conjunction with the false discovery rate procedure were applied to series from 178 rain and 102 river gauges, with record lengths ranging from 30 to 88 years. When autocorrelation was significant, pre-whitening and trend-free pre-whitening procedures were applied. Results illustrate the effects of ignoring autocorrelation and multiplicity in the interpretation of the results, suggesting these factors should be carefully analyzed and incorporated in trend detection studies so as to avoid large number of false detection. A relatively large proportion of gauges located at the main two regions of the basin were declared non-stationary (5% significance level) for Ndays (20% - 30%), SDII (30%) and Qmin (70%), and 30% of gauges in the Middle region for Qmax.

“Green City, Clean Waters” (GCCW) is Philadelphia Water Department’s Updated Wet Weather Long Term Control Plan that intends to reduce/control the stormwater entering the City’s combined sewer system through the use of green stormwater infrastructure. Since the adoption of GCCW in June 2011, the modeling efforts to represent, evaluate and guide the program have advanced. The growth of the program has led to an increase in data collection and general information about the collection system, which improves the hydrologic and hydraulic (H&H) models.

The relationship between the NRCS Curve Number (CN) and rainfall depth (P) was explored in eleven New Jersey watersheds ranging in area from 5.2 to 166 km² and in percent imperviousness from 0.6% to 29.4%. Discharge from each of the watersheds was measured at a USGS stream gauging station co-located with a precipitation gauge. Between 9 and 21 storms exceeding a minimum rainfall depth of 0.25 cm (0.1 inch) were analyzed at each station from April through July 2014. The maximum P was greater than three inches in every watershed. Baseflow was separated from streamflow to give stormflow for each storm, which was converted to stormflow runoff depth (Q). The CN corresponding to each storm was back calculated from P and Q data pairs using the standard CN equations with initial abstraction, Ia, equal to 0.20S (CN20) and 0.05S (CN05) where S is maximum retention. No consistent relationship was observed between CN20 and P for particular storms for any watershed. The CN-P data were reanalyzed using ordered (i. e., frequency-matched) data. The relationship between CN20 vs. P found for 10 of 11 watersheds in this study was atypical compared to what is reported in the literature, emphasizing the complicated nature of the variation of CN within and among watersheds. Several watersheds displayed the characteristic of “violent” behavior with an increase in CN at larger P. The relationship between CN05 with CN20 was similar to the direction and sensitivity of a literature relationship but mostly offset. A weak, positive relationship was observed between the median ordered CN05 for a watershed and watershed imperviousness.

Quantifying topographic characteristics of a surface requires employing digital elevation models (DEMs), which are fundamental input data for hydrologic models. Selecting a proper DEM resolution for modeling depression-dominated areas is complex and reliant on several major factors. This study is aimed to improve the efficiency and effectiveness of DEM-based hydrologic modeling by identifying a threshold DEM scale. To accomplish this, a puddle-to-puddle (P2P) hydrologic model was used to simulate hydrologic processes for a depression-dominated site in the Prairie Pothole Region (PPR) in North Dakota. In the P2P modeling system, a puddle delineation (PD) algorithm was used to characterize surface microtopographic features. Scale analysis was then performed for 70 different DEM resolutions, ranging from 2 m to 105 m, and a threshold DEM resolution was identified for the surface based on the fractal analysis and two dimensionless parameters. The simulation results from the threshold resolution were compared with those from all other DEM resolutions to evaluate the influences of DEM scales on simulations of surface runoff and puddle characteristics. The results of this study accentuate the threshold behavior of depressions. In addition, a power functional relationship between depression characteristics and DEM scales was identified, which can be further utilized for scaling to accomplish efficient and effective hydrologic modeling.

A groundwater system model was developed and calibrated in the study area of Lehman Creek Watershed, eastern Nevada. The model development aims for integrating the surface hydrologic model-precipitation runoff modeling system (PRMS) model-with the three-dimensional (3D) finite-difference model MODFLOW. A two-layer groundwater model was developed with spatial discretization of 100 x 100 m grid. The water balance was estimated with inflows of gravity drainage and initial streamflow estimated from a calibrated PRMS model, and with outflows of spring discharges, boundary fluxes, and stream base flow. A steady-state model calibration was performed to estimate the hydraulic properties. The modeling results were able to represent the geographic relieves, simulate water balance components, and capture the hydrogeologic features. The preliminary results presented in this study provide insights into the local groundwater flow system and lay groundwork for future study of interactive influences of surface hydrologic variation.

Planning of stormwater management projects require the use of current and future rainfall frequencies of specified return periods. NOAA Atlas 14 volume 9 contains estimates of precipitation depth-duration-frequency (DDF) curves along with associated 90% confidence intervals and annual maxima series (AMS) at 242 weather stations in the state of Florida. The DDF curves were developed by NOAA using all precipitation data available at each weather station for the period between 1840 and 2012. The U.S. Bureau of Reclamation has developed bias-corrected and statistically-downscaled climate projections from the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5), which can serve as a basis for future DDF curve development. In order to correct for biases in modeled precipitation extremes, the multiplicative quantile delta mapping (MQDM) is employed. Due to the need for using similar lengths for current and future periods in MQDM, there is a need to fit DDF curves fit to NOAA Atlas 14 AMS data for the current baseline period defined as 40-50 years centered at approximately the year 1970. Methods for fitting consistent DDF curves to NOAA Atlas 14 and USBR’s “Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections” precipitation data for current baseline and future periods of interest are presented and contrasted. Bias-corrected DDF curves for future periods of interest based on MQDM will be presented as well.

The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller creeks, five wastewater treatment plants, and groundwater discharge to the Chehalis River. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure’s impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed for the years 2013 and 2014. Once calibration was complete, model scenarios for future climate conditions and dam operating regimes were conducted. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river.

Mechanistic models of the hydrodynamics and water quality were developed for Lake Kachess and Lake Keechelus in the Yakima River Basin of Eastern Washington. These models were coupled to a fish bioenergetics model and used to explore management strategies to improve water quality in the reservoirs affecting kokanee production. The models were also applied to evaluate the impacts of the proposed implementation of the Kachess Drought Relief Pumping Plant (KDRPP) projects. The public domain model, CE-QUAL-W2 Version 4 was adapted to model the reservoirs. CE-QUAL-W2 is a 2-dimensional (longitudinal-vertical) hydrodynamic and water quality model capable of predicting water surface, velocity, temperature, nutrients, multiple algae, zooplankton, periphyton, and macrophyte species, fish bioenergetics, sediment diagenesis, dissolved oxygen, pH, alkalinity, multiple CBOD groups, multiple suspended solids groups, multiple generic constituents (such as tracer, bacteria, toxics), and multiple organic matter groups, both dissolved and particulate. The model is set up to predict these state variables at longitudinal segments and vertical layers. Comparisons of field data to model predictions were made for water level, temperature, NH4-N, NO3-N, PO4-P, total N, Total P, total organic carbon, alkalinity, zooplankton, pH, chlorophyll a, and dissolved oxygen at multiple reservoir sites at various depths.

In the last few decades, the wetland area of Sanjiang Plain in Northeast China has shrunk severely. To provide a scientific basis for the protection and restoration of wetlands in Sanjiang Plain, author used the remote sensing technology to interpret Landsat TM image of 13 typical years of 4 well preserved and contiguous wetlands (total area:2275.26km²) in the hinterland of the Sanjiang Plain, Naoli River Drainage Basin. According to the results of interpretation, calculation of the ecological water requirement of the 4 wetlands was carried out, using the method of combining ecology with remote sensing technology. According to the structure and actual demand of wetland ecosystem, ecological water requirement of wetlands were divided into two levels, the minimum and optimal. The minimum ecological water requirement was to restore the wetland area in the core area to near natural state in 1984; the optimal one was to restore the core area and buffer area of wetlands. At the same time, considering the rainfall and overland runoff of the different guarantee rate, the artificial recharge of 4 wetlands was calculated according to principle of water balance. The results indicate that wetland area has severely degraded, and decreased by 56.99% from 1963.82km² in 1984 to 846.71km² in 2013. In addition, natural inflow of water can’t meet the actual water requirements of wetlands. Under the 75% and 95% guarantee rate, the minimum artificial recharge is 1.66×10⁸m³ and 2.54×10⁸m³ respectively, and under the 50% guarantee rate, the optimal artificial recharge of the wetland is 3.86×10⁸m³.

Global climate models (GCMs) statistically downscaled GCM output is available for Philadelphia but model resolution in space and time (daily time steps) is too low for direct use in model-based assessments. Additionally, GCM output does not accurately represent local precipitation patterns. Due to these limitations, it is not possible to directly apply GCM output to high resolution time series for use in hydrologic and hydraulic models. This paper presents an innovative approach to generate a high resolution time series considering the Representative Concentration Pathway 8.5 (RCP8.5) climate scenario while preserving local precipitation patterns. In this method, a stochastic rainfall generator was created using seasonal hourly observed time series data as a probability set. The generator was assessed for accuracy against Philadelphia International Airport hourly data and proved highly accurate. The generator, used in combination with the Delta Change Method to apply GCM output to local precipitation time series data can produce highly realistic hourly precipitation time series based on GCM daily precipitation estimates for the period 2080–2100.

The County of San Diego recently implemented the first phase of a flood warning system for the 420 square mile San Diego River Watershed. WEST Consultants created the flood forecasting system using the U.S. Army Corps of Engineers’ HEC-RTS (real time simulation) software. The flood forecasting system is intended to provide San Diego County staff with timely information on potential flooding to support emergency response planning and operations. The flood warning system provides near real-time forecast streamflow at designated locations within the San Diego River Basin. A web site was also created for the County that displays static inundation maps linked to stages at key locations to show a range of inundation conditions. The system’s ability to produce forecasts of hydrologic conditions, including potential inundated areas and overtopping of road crossings, will provide lead time for the County to mobilize field crews to close hazardous crossings and possibly issue flood warnings.

One of the most challenging inputs for the models that estimate pollutant load in watershed outlets, is quantifying the values of nutrient event mean concentration (EMC) or the export load released from different landuses. Many studies have measured pollutant loads from agricultural or urban landuses and majority of them have focused on total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) pollutant loading into watershed in a specific region. In some cases, the EMC or export load values reported in each of the studies have a wide range of magnitude for a specific landuse. The sources of the difference in the pollutant loading values for each of the landuses could be due to the region and physical characteristics (e.g. slope and soil type) of watershed, methods of measuring EMCs and loads, the number of samples taken from watershed outlet and rainfall intensity. This paper summarizes and combines some published EMC and load values separately categorized for urban and agricultural lanuses. Then, for each of the landuses, a box and whisker or statistic plots were created using median EMC and load values, which are reported in different literatures. Because the results of this study are supposed to be used as an input for Kentucky Nutrient Model (KYNM), the studies that report EMC and load values in State of Kentucky were incorporated in the data as much as possible. The provided range of EMC and load values could be very useful for the users of water quality models who need to have a holistic idea of pollutant magnitude released from each landuse in watershed outlets.

Estimation of runoff is important for the design of storm sewers. For the design of storm sewers in the urban area it is necessary to have a short duration rainfall data of station. Availability of proper data of continuous short duration rainfall data is an issue in several cities of India. With the changing rainfall pattern due to global climate change scenario it becomes essential to take into consideration the new values of rainfall intensities for design and modification of stormwater drains of cities. The city of Vadodara also known as the cultural capital of Gujarat has been recently added to the list of cities being developed as smart cities in India. It is therefore in the process of upgrading the existing infrastructure as well as developing new infrastructure in the city. With the changing rainfall pattern the city has been having high intensity rains and thus is facing problems of urban flooding since the last few years. The existing storm water drains have been designed several years ago and therefore need to be analysed for the carrying capacity. This study attempts to analyse the change in the rainfall pattern as well as develop new intensity-duration-frequency relationship for analyses of existing stormwater drains and design of new stormwater drains.

In the present study, an attempt has been made to describe the environmental flow condition of a catchment using the relationship between Standardized Precipitation Index (SPI), a drought index based on the precipitation. Ghatora, Kurubhata, Salebhata and Andhiyarkhore are the four watersheds of Mahanadi Basin have been taken for the analysis. The purpose of this study is to derive relationship between environmental flow condition and the corresponding estimates of Standardized Precipitation Index which is used as measure of drought conditions. It is expected that these relationship will be useful in determining environmental flow conditions in ungauged sub-basins using rainfall data only. The study revealed an excellent relationship between SPI and percentage of average annual flow as the value of coefficient of determination are greater than 0.64. The analysis indicates that for each of the four watersheds the percentage of average annual flow increases with the increase in the value of SPI. It can be concluded that the relationships presented in this paper will be useful for estimating the EF condition for ungauged watersheds.

An uncertainty analysis of standardized precipitation index (SPI) with respect to the length of the sample used for parameter estimation is carried by assuming non-stationary precipitation series. Sampling properties of SPI, such as bias and root mean squared error (RMSE), are analytically derived for normal distributed data. Results indicate that, in terms of RMSE, SPI values are significantly affected by the size of the sample adopted for its estimation. In particular, in the presence of a linear trend, a minimum RMSE value can be determined corresponding to a specific sample size. This suggests that an optimal sample size (in RMSE sense) can be determined, when the underlying series is affected by trend. Furthermore, Monte Carlo simulation experiments reveal that detrending procedures are not recommended for samples whose size is smaller than a given value related to the slope of the linear trend.

The stochastic empirical loading and dilution model (SELDM) was used to demonstrate methods for estimating risks for water-quality exceedances of event-mean concentrations (EMCs) of total-copper. Monte Carlo methods were used to simulate stormflow, total-hardness, suspended-sediment, and total-copper EMCs as stochastic variables. These simulations were done for the Charles River Basin upstream of Interstate 495 in Bellingham, Massachusetts. The hydrology and water quality of this site were simulated with SELDM by using data from nearby, hydrologically similar sites. Three simulations were done to assess the potential effects of the highway on receiving-water quality with and without highway-runoff treatment by a structural best-management practice (BMP). In the low-development scenario, total copper in the receiving stream was simulated by using a sediment transport curve, sediment chemistry, and sediment-water partition coefficients. In this scenario, neither the highway runoff nor the BMP effluent caused concentration exceedances in the receiving stream that exceed the once in three-year threshold (about 0.54 percent). In the second scenario, without the highway, runoff from the large urban areas in the basin caused exceedances in the receiving stream in 2.24 percent of runoff events. In the third scenario, which included the effects of the urban runoff, neither the highway runoff nor the BMP effluent increased the percentage of exceedances in the receiving stream. Comparison of the simulated geometric mean EMCs with data collected at a downstream monitoring site indicates that these simulated values are within the 95-percent confidence interval of the geometric mean of the measured EMCs.

In this study, reservoir simulation model is developed and the results of the simulation model have been incorporated for the development of the Fuzzy rule based reservoir operation model. The steps involved in the development of the Fuzzy rule based model include construction of the membership function for the monthly inflows, based on the frequency distribution of the historical inflows data. The monthly storage and releases membership function is constructed based on the results obtained through the simulation model. Simulated reservoir operation provides the knowledge base necessary for the formulation of the Fuzzy rules. The aim of this work is to apply the fuzzy logic approach to represent the results of the simulated operation of a system in a simple and understandable to the reservoir operators. This framework uses a fuzzy rule-based system to reproduce the results of the simulation model in the form of surface viewer for the time period. It provides the decision support for the real-time reservoir operators under uncertainty. The methodology is demonstrated through the case study of the Sukhi irrigation project in the Narmada Basin, Gujarat, India.

Watershed models are important tools for studying the impacts of natural and human factors on hydrologic processes and watershed responses. Recently, SWAT model has been used as an effective hydrological transport model for evaluating the impacts of climate change on watersheds. It can operate on a daily time step with up to monthly or annual incremental steps. At the catchment scale, the model consists of components in climatology, hydrology, erosion/sedimentation, nutrients, channel routing, plant growth, and agricultural management. The software performs water mass balance basing on input data including, digital elevation model (DEM), soil type, land use, climatic data (temperature, precipitation, solar, relative humidity, and speed of wind). All models are usually calibrated prior to simulations. However, different hydrologic response to varied climatic conditions might affect model calibration and validation. This study evaluates the capability of SWAT in two different extreme climatic conditions in a watershed, one with droughts lasting over years and the other with snowy winter seasons. Another objective is to know how well the ArcSWAT model performs in simulating a typical watershed effectively in a cold region particularly in the periods when there are more snow packs and early snow melting conditions. The watershed of Baldhill Dam in North Dakota was used as a case study area.

The NRCS Curve Number method is used to perform different rainfall-runoff analyses for different land use and soil conditions around the world, such as the estimation of design floods for small hydraulic structures, and best management practices to reduce agricultural non-point source pollution. Knowing that the calculated runoff is more sensitive to the curve number value than to the rainfall depth, estimation of the curve number values for local situations is pertinent. This study focuses on the effectiveness of the asymptotic method in determining curve number values for several agricultural management systems in the Southern USA, and analyzing effects of changing the initial abstraction ratio on these determinations. Runoff predictions are compared with observed datasets and model efficiency is determined contrasting differences based on variation of the initial abstraction ratios.

Recent developments in hydraulic modeling programs, HEC-RAS in particular, have increased the popularity of 2D modeling in the industry. Two-dimensional hydraulic models improve the accuracy and flexibility of flood models, especially in complex situations. However, 2D models often require the use of an unsteady flood hydrograph for analysis of the study area. For this project, we developed a tool that accesses streamflow data from any user-specified USGS stream gage and then analyzes the annual peak flow values to produce a peak flow for a user-specified return period. Then, the peak value and SCS Unit Hydrograph ratios were used to produce a preliminary flood hydrograph of a user-given duration. Statistical analysis of the yearly maximum streamflows was performed using the guidance provided in the Bulletin #17B Guidelines for Determining Flood Flow Frequency, which employs a Log-Pearson Type III distribution technique for determining the peak flow. The Python script produced by this project creates a comma separated values (CSV) file for a preliminary flood hydrograph based on user-determined information that can be used in 2D modeling simulations.

This study is to develop a GIS-based numerical tool for assessment of water balance, runoff and pollution transport caused by point and non-point sources in watershed and river systems. The model tool contains three main modules; the pre-processing tool based GIS functions, the runoff calculation for water balance and nutrient load based on the theory of Generalized Watershed Loading Functions with a number of enhancements and modifications, and the routing calculation engaging with HEC-RAS model for the hydrodynamics and transport processes in river systems. All components are immersed into an open source GIS MapWindow software (www.mapwindow.org) as plug-ins. The modeling tool is programming in VB.NET, and designed to complement and interoperate with enterprise and full-featured under MapWindow GIS functions. A GIS-based numerical tool makes watershed and water quality studies easier by bringing key data and analytical components under one GIS (geographic information system) roof. Through the use of GIS, the model has the flexibility to clip, integrate and display a wide range of information (e.g., basins, streams, weather, land use, soils, point source discharges, water supply, withdrawals, nutrient loads, etc.) at a scale chosen by the user. Minimum data requirements and effective application are advantages of this modeling tool. The model has been verified and validated against available well-known watershed models and observation data obtained from real applications for watershed systems in USA and Vietnam.

This paper presents the application of a two-dimensional numerical model for simulating the flow fields and water quality distributions in Beasley Lake, an oxbow lake in the Mississippi Delta. In this lake, wind shear is the major driving force for flow hydrodynamics. The flow fields, nutrients and chlorophyll concentration in Beasley Lake were simulated using CCHE2D, a hydrodynamic and water quality model developed at the National Center for Computational Hydroscience and Engineering. The effects of runoff and sediment from upland watershed on the lake water quality were taken into accounted. The simulated results were validated using field measurements. It was found that the chlorophyll concentration is greatly affected by suspended sediment concentration in the lake.

The water supply concerns in California, including the implementation difficulties in meeting the legal requirements of SBx7-7 and those proposed by the Sustainable Groundwater Management Act (SGMA), has stimulated efforts to devise improvements in irrigation delivery methodology. These improvements include the quantification of delivered waters. The availability of ultrasonic Doppler techniques and trans-sonic technologies have recently added to the assortment of flow measuring methods. Also, innovations concerning proven older devices have been introduced or proposed, further adding to the mix. Desirable characteristics of all these measuring techniques include accuracy, economics and convenience of use. The accuracy component, has generated much debate because legal compliance, which allowances accuracies to within 10%-15%, raises concerns for water management decisions that may depend on narrower error allowances (<5%) in order to identify water users that are to be emulated and water users that need special assistance. Herein, the discussion, while mentioning the new technologies, emphasizes modifications of some old measuring methods that take advantage of understandable technology for semi-skilled installation, reliable low maintenance and long life. Included are weed resistance, and proposals to enable sluice gates capable of measuring submergence, transitional, and free flow operations.

West Stanislaus Irrigation District (WSID) provides agricultural irrigation water to about 22,000 acres in the San Joaquin Valley. The majority of WSID’s water is diverted directly from the San Joaquin River, with supplemental water obtained from the Delta-Mendota Canal (DMC), groundwater wells, and a variety of other sources. WSID operates a series of pumping plants that lift water from the San Joaquin River sequentially into six short canal reaches. Each main canal pool supplies one or two laterals along the valley contour. Water from the DMC enters the district via a gravity pipeline at the tail end of the main canal. Water supply curtailments, regulatory changes, and significant increases in drip/micro irrigated acreage have steered the district and its board members towards modernization of its original 1920s-era infrastructure. To that end, the Cal Poly Irrigation Training and Research Center (ITRC) has worked in cooperation with WSID since the early 2000s on a phased modernization planning and implementation process. Following a Main Canal Modernization Study, significant improvements have been executed along the main canal including the automation of all original pumping plants and lateral headings as well as the construction of two new, automated pumping plants. An industrial-grade Supervisory Control and Data Acquisition (SCADA) system has also been commissioned. Further project planning is underway at the San Joaquin River diversion and throughout the lateral canal system. This paper describes the modernization process and results. Lessons learned throughout the various projects are also discussed.

Relatively accurate flow measurement at irrigation district water delivery points is an important component of volumetric billing and equitable service. In California, this has often occurred with conversions to pressurized irrigation systems which commonly include the installation of pipeline flow meters as part of the on-farm system. However, a large portion of irrigation turnouts in the western U.S. continue to operate via gravity and fall into one of the following categories: (a) a metergate, or similar structure was installed without adherence to standard construction requirements, or (b) the structure was never intended for flow measurement. For these and other scenarios, there is a need to efficiently calibrate turnouts in the field. While some in-situ calibration methods exist for open channel turnouts, they are rarely applied in the field for a variety of practical reasons. After identifying this gap in field-practice, a special pump, or portable irrigation turnout calibration unit (calibration unit) was designed and constructed at the Cal Poly Irrigation Training and Research Center (ITRC). Within six weeks, thirty-two field turnout calibrations were performed using the Calibration Unit throughout seven California irrigation districts. Field testing protocol followed new guidelines developed by the USBR Mid Pacific Region and the California Department of Water Resources (DWR). The results and analyses of these calibrations are presented in this paper. Practical applications, such as compliance with California regulations developed out of The Water Conservation Act of 2009 (SB X7-7) and constraints of this new calibration method are also discussed.

Agriculture drainage increased from the early 1900s to the early 1980s. During the 1970s and 1980s increasing environmental concerns increasingly viewed agricultural drainage as being against the public’s best interests. The Clean Water Act amendments in 1977 and the Food Security Act of 1985 all had an effect on agricultural drainage. Water quality effects of agricultural drainage projects started to be reported in the literature in the 1970s and 1980s. There were a number of projects conducted in the Northeast. To address water quality concerns, some controlled drainage systems were installed on the Delmarva Peninsula in the 1990s. Research has shown subsurface drainage can transport large amounts of nitrogen to surface waters. New York has a large dairy population, so manure is the largest input of nitrogen to surface problems in a number of watersheds. Also of concern is the rapid transport of nitrates and bacteria by preferential flow to subsurface drains when liquid manure is spread on fields. On the Delmarva Peninsula poultry manure has been a great concern for many years of in the Chesapeake Bay and Inland Bays watersheds. With the release of the TMDL by EPA in 2010 for the Chesapeake Bay it has become more of a concern.

The occurrence of algae blooms in the U.S. waterbodies has become an annually recurring phenomenon. Lake Erie of the Great Lakes (North America) has been experiencing significant and harmful algae-blooms (HABs) during the mid-July to mid-September for more than ten (10) years now. The watersheds in the U.S. are significantly affected by algae-bloom formations during the summer months, and, this has been a vicious cycle that the point and non-point wastewater effluents contribute nutrients to waterbodies, specifically during the Spring time, and the need to draw those intake waters to effectively treat those complex algal-blooms forming during the summer time in maintaining the uninterrupted supply of the potable water to cities and towns. Good reductions of total phosphorus (TP) loadings to Great Lakes, specifically to the Lake Erie, were accomplished compared to the 1970s; however, the non-point source TP loading to Lake Erie has been significant and varying year-to-year. More effective TP estimation methodology with respect to the phosphorus discharging sources will be required. Additional TP reductions are necessary toward a good water quality of Great Lakes. Interim open water TP concentrations and loadings are in effect since 2012, until updated. The Phosphorus Task Committee has recommended that March to July total Spring phosphorus loads should be reduced, and some of the basins of Lake Erie the nutrient load must be reduced as much as by 40%. The best management practices (BMPs) have been identified and recommended to be put into practice. In this work, authors focused on: Great Lakes’ water-asset; nutrient TP loadings to Great Lakes and effects; the Great Lakes Water Quality Agreement (GLWQA), on nutrient TP concentration and loading targets; TP including the dissolved reactive phosphorus (DRP) loading targets to the Lake Erie; a review on Lake Michigan; and, the binational (Ca and USA) action plans for TP reductions and, nutrient and excessive algae-bloom control requirements.

Accurate evapotranspiration (ET) estimation is essential to crop water management and irrigation scheduling. As a major agricultural area, North Dakota lacks studies on crop ET measurement for major crops. In this study, an eddy covariance system (EC) and two sets of soil moisture sensors were installed to measure cool season grass ET and estimate the crop coefficient (K_c) in eastern North Dakota from January 2011 to December 2013. The residual energy balance and Bowen ratio method were used to calculate the latent heat flux (LE) and ET values. Priestly-Taylor method also was used to estimate the missing values. Daily and monthly variability in fluxes and ET were quantitatively analyzed. For the study period, the soil moisture content for grass root zone has been continuously monitored and the relation between flux data, weather data, and soil moisture content were illustrated. The results showed that the growing season ET during 2011–2013 ranged from 560 mm to 773 mm from April to October, with the highest ET in July. The annual difference in ET was related to differences in weather and soil moisture conditions. The K_c for grass was developed as a ratio of actual ET measured by the EC, and the reference ET using ASCE-EWRI ET reference method. Seasonally, the highest ET and K_c were observed in July and April, respectively. The average K_c values for 2011, 2012 and 2013 were 0.97, 0.65 and 0.85, respectively. Therefore, 0.8 is recommended Kc value based on cool season grass as a reference crop for the study area during the growing season.

The study of spatial and temporal variations of infiltration in furrows is essential for the design and management of surface irrigation. A key difficulty in quantifying the process is that infiltration is dependent on the depth of flow, which varies along a furrow and with time. An additional difficulty is that under many field conditions, a large fraction of the infiltrated water flows through macropores. This study evaluates a proposed furrow infiltration model that accounts for both effects. Flow depth dependent infiltration is computed based on porous media flow theory. The macropore contribution is modeled as water that infiltrates instantaneously. Parameter estimation techniques were used to determine two of the model parameters, the hydraulic conductivity and the macroporosity term, and the Manning roughness coefficient. The methodology was tested using 30 furrow irrigation data sets collected in 6 furrows over 5 irrigation events. The analysis produced reasonable estimates for hydraulic conductivity relative to values reported in the literature. The estimated macroporosity term exhibited greater variation between irrigation events than between furrows during an event. Irrigation simulations were conducted with the estimated infiltration and roughness parameters. The observed irrigation measurements (advance, recession times, outflow rates, and flow depths) were simulated with reasonable accuracy for all events. Results show that the proposed furrow infiltration model can represent the infiltration process reasonably and that the proposed estimation procedure can yield consistent infiltration and hydraulic resistance parameters. Results also illustrate the large infiltration variability that can be encountered in furrow irrigated fields.

With the advancement of computation and sensor technology, new strategies and tactics are being employed in the development of state-of-art operations tools in energy and water resources management. As agriculture is one of the sectors that consumes significant amount of energy and water, these cutting edge tools are particularly important for their management. While one strategy to save energy cost may come from the optimum pump operation considering peak and off-peak hours, the real energy reduction can result from monitoring the water conveyance system regularly and delivering the true water demand at optimum pressure requirement. Similarly, water consumption can be reduced by calculating the true water demand, using correct irrigation method, application time and frequency, and monitoring the conveyance system. This study proposes a framework to reduce energy and water usage in irrigation water distribution system (WDS) by quantifying correct crop water demands through utilization of soil moisture information, weather data, and hydraulics information including flow and pressure throughout the system. Results show that about 13 to 24% water savings is possible when feedback from soil moisture sensor is considered. Similarly, additional 10% water savings is possible if field capacity is considered to be the upper limit for irrigation which will save about 6% of pumping energy consumption.

Drainage water recycling, storing subsurface drainage water for reuse as irrigation water, is a practice that is gaining interest to meet both production and environmental goals. There is limited research on the feasibility of this practice in Iowa and the rest of the U.S. Corn Belt. The objectives of this study were to quantify net irrigation requirements at multiple locations in Iowa, the potential supply of subsurface drainage water that could be stored for reuse, and the frequency that stored drainage water would be adequate to meet crop water demands. The growing season net irrigation requirement ranged from 114 mm to 269 mm for maize and 103 mm to 259 mm for soybean. The mean annual subsurface drainage depth was 226 mm. In 50% of years that irrigation was required, subsurface drainage water was adequate to fully meet crop water demands. These results are the first step towards understanding the feasibility and design requirements of drainage water recycling systems in Iowa.

This paper presents a flexible method that is real options to measure the value of the water infrastructure systems. In particular, it analyzes: net present value (NPV), decision analysis (DA) and real options analysis (ROA), and compares these approaches in terms of their handling of uncertainty linked to climate changes, their acknowledgement of flexibility, and their usefulness for strategic investment decision making in the water sector. The study is illustrated by a system design for the expansion of the desalination plant to a capacity of 2m³/s in the city of Agadir located in the south of Morocco. This study illustrates the application of each methodology and identifies the policy challenges relevant to desalination investment evaluation and other evolving economies. Real options make a flexible ability to respond the systems more effective to good opportunity and withdrawn unproductive situations from loss of investments in the future. The results of this approach are compared with traditional net present value in cases of with and without uncertainty to show expected values of investment of water demand and supply schemes. It shows that real options in water system design can increase expected value of water infrastructure investment by reducing negative risks and increasing opportunities.

The Brazilian interconnected power system consists of 153 medium and large hydropower plants, and is complemented by a large set of small hydropower, thermal and wind power plants. Hydropower is the predominant source of energy supply and on average represents 85% of total energy consumption in the country during the last ten years. Inflow forecasts are required for the planning and operation of the power system. The current practice is to utilize a set of streamflow forecasting models to predict reservoir inflows, which are used as inputs to the optimization models. The purpose of the study is to evaluate the accuracy of the forecasting models that are being used by the electric system national operator (ONS). We use statistical analysis by comparing the forecasts with historical observations at various reservoir sites and different seasons. Short-term forecasts are important for real-time operation, mainly for flood control and unit commitment. For monthly planning and operation, the hydro system optimization model uses deterministic reservoir inflow forecasts for the first month and different scenarios to represent future possible inflows after the first month until the end of the planning horizon. The optimization model is solved by stochastic programming with recourse and is updated at the beginning of each month. This paper evaluates the accuracy of monthly inflow forecasts for all the medium and large hydropower plants in Brazil. We intend to answer the following questions. How is the goodness of fit among different periods and river basins? How can the forecasting models be improved?

The Paraíba do Sul River Basin is an important basin located between the largest industrial region and densely populated cities in Brazil. The basin includes parts of the states of São Paulo, Rio de Janeiro and Minas Gerais. Main water uses include public supply, irrigation, wastewater disposal and hydropower production. Five storage reservoirs with hydropower plants are used to regulate inflows and produce hydropower. To comply with water supply security and environmental protection requirements, additional operational constraints on storage levels and releases are being imposed. The 12 million inhabitants in the Rio de Janeiro metropolitan region receive their main water supply from the reservoir system. To improve water supply safety after the severe drought of 2012-2015, a new water transfer project is being built in the São Paulo metropolitan region that has 20 million inhabitants. The 2012-2015 drought affected several basins in Brazil and required reduction in minimum release constraints on the reservoirs of the Paraíba do Sul River Basin. Moreover, construction of the new water transfer project requires a temporary reduction of the maximum storage levels. In this paper we use the HIDROTERM, a nonlinear programming optimization model previously developed for planning the operation of the Brazilian hydrothermal system, to evaluate the impact of the additional constraints and changes that are imposed on the reservoir system. Specifically, we use different hydrological scenarios to evaluate the impact on hydropower production and other water uses as well as the risk of not meeting the constraints.

The public does not understand recurrence intervals for 100-year storms, which can occur more frequently than once every 100 years. A better way of communicating the severity of these rain storms to the public is to use a dimensionless index similar to ratings for other natural disasters (e.g. Richter scale for earthquakes, Fujita scale for tornadoes, and Saffir-Simpson scale for hurricanes). The public understands the ratings for these events which use a simple scale to rate the severity of the event, not the rarity of the event. This paper proposes a dimensionless scale for severe rainstorms, building upon existing data that rates the event on a simple scale, based on its severity. This helps the public understand that extreme rains can occur more frequently than otherwise thought, incenting the public to take steps to protect themselves from the impact of these severe storms, instead of falsely assuming that they are “safe” for another 99 years. This will become more important as the climate continues to change, which can change the frequency of occurrence of these events.

The Sacramento and San Joaquin Basins Study is a collaborative long range planning study conducted by the U.S. Bureau of Reclamation and state and local partner agencies to assess the impacts of future changes in climate and socioeconomic conditions on water resource management in the Central Valley of California. To account for a range of uncertainty in future conditions through 2100, a scenario-based approach was developed using climate projections available from Couple Model Intercomparison Project Phase 5 (CMIP5) climate model simulations and sea level rise projections consistent with National Research Council (NRC) and the most recent Intergovernmental Panel on Climate Change (IPCC) Assessment Report 5 (AR5). The performance of the Central Valley water system was evaluated for a range of metrics including water deliveries, water quality, hydropower, flood control, recreation, fish, and wildlife habitats, ESA species, flow dependent ecological resiliency and the economic impacts of water supply changes using an integrated model package that simulates the federal Central Valley Project, the State Water Project and local system operations and regulatory requirements. The study also included the development and evaluation of a range of water management actions that can help reduce or manage future risks posed by potential changes in climate and socioeconomic conditions. Seven adaptation portfolios were explored that each consisted of a variety of water management actions. These thematic portfolios were evaluated to determine their effectiveness in adapting to potential risks posed by future socioeconomic and climate changes and to assess tradeoffs between their relative performances.

This research evaluates streamflow forecast skill in the context of drought planning for the City of Baltimore’s water supply system. Forecasts generated by the National Oceanic and Atmospheric Administration’s (NOAA’s) National Weather Service’s Middle Atlantic River Forecast Center (MARFC) are integrated into a systems model to assess the value of streamflow forecasts on operational performance during drought. This research intends to measure forecast benefits by comparing the NOAA/MARFC generated forecasts to simple statistical forecasts and perfect forecasts. Operating policy scenarios are to be evaluated to identify a robust operating rule that balances three key metrics: (1) storage levels, 2) economic loss, and 3) the frequency of drought declaration error. This multi-objective study demonstrates the value of near-term forecasts, and potential future long-term forecasts, in improving system performance.

The Tarrant Regional Water District (TRWD) owns and operates two reservoirs in the West Fork of the Trinity River Basin located near Fort Worth, TX. The District operates these reservoirs to reduce flood flows into the Fort Worth Floodway, a 27-mile stretch of the West Fork of the Trinity River located in Fort Worth. In addition, TRWD operates 32 sumps along the Floodway. TRWD uses a decision support system—Aviso FS—to make operational decisions using forecasted runoff from observed precipitation. The use of this DSS enhances reservoir operators’ abilities to evaluate and meet competing objectives regarding lake levels and downstream releases. This paper describes TRWD’s use of Aviso FS during a flood event in Spring 2016 to minimize the flood’s impacts on people and infrastructure.

A 3D hydrodynamic and temperature numerical model was developed and calibrated for Lake Chaplain, Washington, USA. The governing equations are the continuity equation, free surface equation, momentum equation, and conservation equation of transport. The model employs the semi-implicit finite difference scheme to solve the governing equations and higher order schemes (QUICK and Quickest) for mass and heat transport in contrast to simpler but more diffusive first order UPWIND scheme. A unique feature of the 3D numerical solution of the model free surface equation is that the solution uses a tri-diagonal matrix form rather than a more common penta-diagonal matrix. The surface heat exchange and turbulence structure were based on the CE-QUAL-W2 model. Comparisons in water surface levels and temperature vertical profiles between model predictions and data were performed using different advective transport schemes. The model matched data with good error statistics.

Water is becoming the most critical natural resource issue facing many Arab Countries resulting from high population growth rate that exceeds by far the rate of developing water resources. This paper tackles the current scarcity problem through three inter-dependent venues with some recommendations aiming to move towards sustainability in water resources management: (i) provides an overview of the demand and supply status in the Economic and Social Committee in West Asia member states up to the year 2050. Demand projections were performed for per capita consumption in domestic, agricultural and industrial sectors, and a total demand for each sector was determined based on projected population figures and respective demands. Then, the break-even year between expected supplies and projected demands was estimated for each member state. Based on the current projections, some countries will continue to depend on surface water, while others will rely on groundwater, desalinated seawater, or non-conventional water resources. To solve water scarcity problems, regional governments should aim at optimum utilization of available water resources, and possibly increase them through exploitation of new and sustainable sources; (ii) proposes and recommends for implementation a set of planning policies, strategies and regulations to reduce shortage and possibly reach sustainability; (iii) furthermore, the study proposes establishing a proper water tariff structure for pricing domestic, agricultural, and industrial water. Finally, implementation of such policies and measures is instrumental to deal with water deficit problems aiming to reach sustainability, while failure to achieve set targets may result in quality and quantity deterioration.

Water infrastructures are of the most vital facilities in urban areas and play an important role in serving the societies. In coastal areas, natural hazards such as flood can significantly threat the coastal infrastructures’ functionality. One way to evaluate the infrastructures performance during flooding is to measure its reliability. Reliability of the system is regarded as the probability of successful operation within the assumed time period. In this study, a framework is presented to analyze the wastewater treatment plants reliability during the time of flooding. The case study is New York City which have had experienced severe storms during the past decades and two major disasters in the last 5 years. Here, the reliability is referring to the ability to maintain water quality standards of effluent in wastewater. In this way, the effluent concentration during flooding is considered as a random variable and it is compared with the discharge standards. The effluent concentration is computed by considering the status of different unit operations of WWTP during the flooding time, which may cause a disturbance and/or reduction in the unit’s performance. For effluent concentration, different distributions functions are fitted and the water quality reliability of all different distributions are compared. The expected compliance with the discharge standards is computed by assuming a level of confidence which shows the reliability of the system. Results show the significant value of quantifying reliability to assess the performance of WWTP. The methodology can be applied to other coastal settings that are subject to coastal and inland flooding.

Urban Flood is one of the biggest environmental problems of the planet. It generates high negative impacts of various kinds: social, environmental and economic. These problems grow exponentially in megacities, since the disorderly occupation of land, coupled with the size of the population, make it extremely complex to control and to manage. Structural measures for flood control are not enough; the city needs to deploy a number of non-structural measures such as a flood warning system. This system aims to provide real-time occurrence and forecast of floods that may cause impacts in several areas of the city. These forecasts trigger a series of actions for civil defense, firefighter, traffic control, social support and other entities. The flood warning system of the São Paulo Metropolitan Region, Brazil, called SAISP system, installed a set of weather radars and telemetry networks, as well as a decision support system (SSD) operated by engineers and meteorologists, which generates a set of forecasting bulletins 24 hours a day during all year long. Several public organizations and press receive these bulletins in real time and a set of actions can be managed in order to minimize the impacts of critical hydrological events. This paper presents some analysis of a flash flood event observed in the Jaguaré River small catchment on February 6^th, 2016 (80 mm in one hour). In this day a set of social works could be done due to SAISP information. Therefore with this event was possible to evaluate a set of social benefits that this type of system back to town. In general is very difficult to assess the social benefits that this type of system produces in a big city, so the information obtained in this event can subsidize the planning of new systems, as overall social benefits are difficult to measure in economic values, because most of them are intangible.

California has already taken actions to reduce flood risk in the Central Valley through investments in the flood management infrastructure and emergency response systems. However, California’s growing population will increase vulnerability and exposure to the flood hazard. Further, a changing climate may expand areas subject to inundation. Lastly, the flood control system that protects Californians in the Central Valley is aging and enhancements are needed. This study tracked the State’s investments and associated flood risk reduction benefits from the recent past to the future, through the planning horizon of the 2017 Central Valley Flood Protection Plan (CVFPP) Update. Here, we discuss how flood risk is assessed over time. We use two indicators of flood risk: expected annual damage (EAD) and expected annual fatalities (i.e., life loss). Both are used to measure the benefit of the investment thus far, and to measure the benefit of future investments in light of changing conditions such as population growth and climate change. We describe inputs to the EAD and life loss computations and how EAD and life loss is computed using HEC-FDA, the standard-of-practice of software developed by the U.S. Army Corps of Engineers (USACE) Hydrologic Engineering Center. HEC-FDA performs integrated hydrologic engineering and economic analysis. We also describe how inputs to EAD and life loss computations are likely to change over time both with and without the activities included in the 2017 CVFPP Update.

Groundwater management strategies should be designed to ensure efficient and sustainable management of groundwater. Optimization models and algorithms can be applied to identify groundwater withdrawals that will satisfy both hydrologic goals and water demands. In groundwater basins where urbanization increases demand and places stress on the supply-demand balance, safe yield based demand restrictions are used to reduce demands. Due to restrictions for water consumers, safe yield-based demand management strategies may result in unintended consequences, such as welfare loss, which is represented as a measure of consumer willingness to pay to avoid water service interruptions. This paper couples an agent-based modeling (ABM) framework and a groundwater model to quantify the improvement in water resources and corresponding welfare losses through mandatory restriction programs and to optimize the permitted yield for applying restrictions. The framework is applied to identify permitted yield as a trigger that should be used to implement restrictions under climate and population uncertainties for a long term planning period for cities in a shared groundwater basin in the Verde River Basin, Arizona. Results indicate trade-offs between groundwater table improvements and welfare losses for changing safe yields. The framework provides a comparison of hydrologic and economic consequences of mandatory restrictions for and reactive management with varying supply-demand balances. The research will guide water restriction policies and improve understanding of the hydrologic and economic consequences of water restriction policies at a basin scale.

The Association of State Floodplain Managers’ (ASFPM) report Meeting the Challenge of Change—which we summarize in this paper—addresses implementation of the President’s new federal standard for flood risk management (Executive Order 13690), including its requirement to consider future flood risk when planning taxpayer-funded projects in areas prone to flooding. Throughout the ASFPM report, the challenges are paired with implementable actions. The report concludes in many cases use of an approach based on climate-informed science will provide better risk estimation and planning outcomes than other “one size fits all” options such as building to the current 500-year flood standard or applying extra freeboard for construction. The report also explores ways floodplain management is meeting the challenge of managing future flood risk, summarizes key provisions of EO 13690, and makes a number of specific recommendations aimed at resolving policy issues, building cooperation and collaboration, and identifying, communicating and mitigating future risk. Meeting the Challenge of Change was prompted by issues raised at the ASFPM Foundation’s Gilbert F. White National Flood Policy Forum held in September 2015. Contributing attendees included more than 100 representatives from government, non-profit organizations, academia and corporate sector.

This work proposes mechanism of assessment (metrics) of multiobjective optimization algorithms (MOA) in calibration of model with base of distribution of points that form the Pareto front. They were used three MOA techniques: MOPSO (multiobjective particle swarm optimization), NSGA II (nondominated sorting genetic algorithm) and PADDS (Pareto dynamically dimensioned search). It was used a test battery applied to these MOA analyzing the results of simulated Pareto Front (PF). The assessment of these MOA were accomplished using three concepts of established metrics: first metric refers to quantity of responses coincident with analytic PF; second metric means the good distribution of responses along the analytic PF and third metric is the root mean squared of responses versus analytic PF. We conclude that proposed metrics are useful to assessment the studied MOA where PADDS showed the best performance for the proposed model.

The extensive withdrawal of groundwater and resulting compaction of the aquifer-system within the San Joaquin Basin is causing land subsidence. The situation is expected to worsen in the next 50 to 100 years. Based on current measured rates of subsidence and potential alternatives from San Joaquin River Restoration Program, the California Department of Water Resources (DWR) produced a projected subsidence scenario for the mid-century and potential mitigation measures. The depths of this projected subsidence vary from approximately 6 feet at the Chowchilla Bifurcation structure to up to 17 feet in areas near the Sand Slough diversion, decreasing northward to near zero at the confluence of the San Joaquin and Tuolumne Rivers. Impacts of variable subsidence include changes to the channel capacity and adjustments to flow delivery patterns. As part of the San Joaquin Basin-Wide Feasibility Study (BWFS) and 2017 Central Valley Flood Protection Plan (CVFPP) Update, DWR has examined capacity impacts of the projected subsidence using Central Valley Evaluation and Delineation (CVFED) Program and Central Valley Hydrology Study (CVHS) tools. The CVFED hydraulic models were modified to reflect projected subsidence and run with flows taken from CVHS that replicate 1) flood conditions and 2) flows that match the design capacity of the Eastside Bypass. Impacts of subsidence include decreased capacity in Eastside Bypass and adjacent additional floodplain inundation in both flood conditions and more frequent design events. The hydraulic model with projected subsidence were then used for sensitivity analysis to explore opportunities to address subsidence-related capacity and overbank flooding issues.

The interaction between sediment and surrounding water is influenced by numerous physical-chemical parameters. The presented sediment transport model allows predicting suspended solids concentration in water phase as a function of applied shear stress, sediment grain diameter, and fish abundance measure. Experiments on erosion of natural sediments in the annular flume at RWTH Aachen University are used for model calibration. Empirical coefficients are evaluated with genetic algorithms to achieve the best model fit. The presented model shows enough flexibility to account for various sediment properties, including different sediment sources, natural and artificial contaminants, presence or absence of aquatic organisms, and results in average determination coefficient R² = 90.4% between the model and the experimental data. Model simulation outcomes clearly show the essential to account for fish activity to predict the resuspension course correctly. Further sediment erosion experiments with carefully chosen conditions will allow more comprehensive model adjustment.

Two examples of water resource design applied following disaster recovery in New Orleans (United States) and Christchurch (New Zealand) are presented in terms of reinstating original design versus adopting more robust and resilient design criteria. Disaster recovery objectives generally include reinstating water service and infrastructure as quickly as possible. There is invariably tension between timeframes, mandates, and funding needed to reinstate services versus incorporating robust and resilient design following natural disasters. The historic development, disaster and design criteria used to repair the flood control and stormwater removal system for New Orleans in the aftermath of Hurricane Katrina are presented. Similarly, the historic development, 2011 earthquake and design criteria to repair the water supply, wastewater and stormwater networks in Christchurch are discussed.