World Environmental and Water Resources Congress 2018: Groundwater, Sustainability, and Hydro-Climate/Climate Change

The continuous emission of carbon dioxide to the environment has caused major climatic changes and is the main cause of the global warming. In order to mitigate the level of carbon dioxide in the atmosphere, the excess amount of carbon dioxide needs to be permanently stored in the deep sedimentary rocks. The pore pressure buildup during carbon dioxide injection process needs to be monitored in order to prevent the failure of the reservoir and hence the leakage of the stored carbon dioxide. In this paper, coupled geomechanical modeling and stability analysis are performed for the Minjur Sandstone reservoir in Saudi Arabia. The pore pressure buildup and ground uplift was calculated during carbon dioxide injection into the reservoir. The Mohr-Coulomb failure criterion was utilized to perform the stability analysis of the reservoir. The stability analysis was performed for the reservoir which suggested safe carbon dioxide injection parameters based on the changes in the pore pressure and horizontal stresses in the reservoir.

A novel drainage system and animal unit flooring system has recently been developed which maximises the comfort and welfare of animals housed on it and at the same time allows separation of urine and faeces, reducing the conversion of urea to ammonia and thus reducing nitrogen release to the atmosphere. The system is based on plastic void forming units originally designed for stormwater control purposes. These units are covered with a perforated foam, made from recycled foam waste, and a high strength textile. Cattle, goats, and horses have been preference tested on this surface and have been shown to prefer it to traditional straw covered flooring. Cattle spend a long time lying down on this surface and this can potentially increase milk yields. A robot is used to clean faeces off the floor continually and if it encounters an animal it will avoid it and return to that place later. Urine is filtered through the textile and is available for use as a liquid fertiliser. This paper reviews the construction of the system and report on the work done on both survival of mastitis-causing organisms in the fabric and foam layers and the drainage behaviour of liquids expressed from the foam by animal movements.

Turag River, passing through the northwestern part of Dhaka City, plays a significant role as the main drainage channel and carries water to the Buriganga River. The major pollution sources of Turag River are untreated effluents from different industrial establishments, domestic, and human waste from surrounding municipalities and slum areas. This study identified and categorized the major sources of pollution and outfalls discharging into Turag River. Evaluation of spatial and temporal variation of surface water parameters was performed throughout a year. Finally, status of heavy metal contamination of different compartments of Turag River such as river water, riverside plants, sediment, phytoplankton, and fish species belonging to different trophic levels was evaluated. Results indicated that currently, Turag River is being polluted by 15 point sources including industrial effluent and municipal sewage. Specific point sources such as Azmeri Knit Composite, Hossain Dyeing, Tongi Bridge waste, Mehmud Industries Limited, and fish market waste were identified within the stretch of the study. Major outfalls included storm sewer pipes, open channels, and small/big private outfalls. Dissolved oxygen was obtained below 4 mg/L in most instances and accordingly, it was difficult to find common aquatic life forms especially during dry season. Levels of biochemical oxygen demand, color, turbidity, total suspended solids, ammonia, and phosphate were obtained beyond the standard water quality ranges especially during dry season. Certain fish species and macro invertebrates were categorized to be endangered comparing current and previous observation. Chromium and lead were detected at negligible levels in the water however, significant concentrations of zinc were obtained in plants, phytoplanktons, and riverside sediments. Pollution load index indicated low level of heavy metal contamination. Bioaccumulation of zinc seemed significant in phytoplanktons whereas moderate level of accumulation was observed in fish species.

Solid waste management (SWM) poses severe problems to the authorities of the city of Kerbala, one of the main tourism centres in Iraq. Due to the city’s limited funds, it is crucial to evaluate the priorities for improvements in SWM services to tackle this problem efficiently. This paper employed Wasteaware benchmark indicators for integrated and sustainable solid waste management to evaluate the city SWM system performance. The data used in this evaluation was collected by in-depth interviews with the management authorities and field observations over two months in 2016. The outcomes showed that the SWM system in the city is weak. It therefore requires several improvements in physical infrastructure and management. Disposal and recycling were the highest priority to be improved among SWM physical components. While, in the management, the authority should have clear strategy for SWM and stakeholders such as public, private waste sector, and informal waste collectors should be included in SWM planning to improve the management services. This study can provide a starting point for the city authorities to prioritise their actions to improve the current SWM system.

The Passaic River watershed drains approximately 2450 square kilometers of terrain. Heavy chemical use in the lower 12.875 kilometers of the Passaic River by industries such as heavy metal extraction from ore and production of pesticides and herbicides contributed towards the heavy contamination. USEPA proposed a $1.7 billion remediation plan that includes bank to bank dredging and capping. The current remediation plan is extremely expensive and comprises risks of resuspension of contaminants. The aim of the study is to use ultrasound and ozone nanobubbles to develop a remediation technology that will adhere to a variety of contaminants present in the river sediments. Laboratory experiments showed promising results indicating the possibility to use ozone nanobubbles and ultrasound to treat contaminated soil. The data obtained from the laboratory experiments will be used to develop a pilot scale study to identify the possibility of for possible field application.

Disinfection of combined sewer overflow (CSO) effluent is necessary to protect surface water sources but can lead to the formation of carcinogenic disinfection by-products (DBPs). For CSOs, higher chlorine doses and/or longer contact times may be needed to meet bacterial effluent requirements. The objective of this work is to determine the DBPs formed at the minimum chlorine dose and contact time that would result in CSO effluent meeting current and proposed bacterial requirements for two facilities with different water quality characteristics. The dominant DBP species that formed at both facilities (A and B) were haloacetic acids (HAAs), which showed higher concentrations at higher initial chlorine doses. Haloacetonitriles (HANs) were only found after chlorination of influent (Facility A) that had higher ammonia concentrations, likely caused by the formation of chloramines. Both facilities were able to meet the current and proposed bacterial requirements at an initial chlorine dose of 6 mg/L and a contact time of 15 minutes. As a measure of risk to downstream users, percent DBP brominated was calculated for both facilities at the same chlorine dose and contact time. Despite the formation of higher total HAA concentration at Facility B, the percent HAA brominated was 69% at both Facility A and B, indicating similar risk to downstream users despite differing total HAA concentrations.

This study aims to clarify the mechanism of overgrowth woodlands that is important issue on flood control and environmental management. We conducted the hydraulic simulation and ecological simulation and consider the cause of overgrowth woodlands. In the result, it is estimated that gravel pit was very important effect on the overgrowth woodlands.

As of today the Virrilá Estuary located in Piura, Peru, is polluted with high nitrate and chlorine concentrations. Because of that the mariculture activity of the towns and cities located in that estuary are significantly affected (which is the basis of their economy). Recent field measurements indicate that the nitrate concentrations are related to the suspended sediment concentrations whereas the chlorine distribution is directly associated with the flow recirculation patterns. In order to shed light on the transport dynamics of these contaminants a two-dimensional shallow water equations numerical model that can predict suspended sediment transport and flow recirculation was developed. Field data measurements were used as input to the numerical model and comprised the pollutants concentration, tides data, wind speed and direction, suspended sediment concentration, inflow discharges, and bathymetry. The results of the numerical model showed that the flow patterns of the estuary are mainly driven by the variation on water levels alone and that the interaction of suspended sediment concentrations occurs only in areas near the mouth of the Virrilá Estuary.

Artificial groundwater recharge (AGR) by flood spreading method is of paramount importance in sustainable management of groundwater resources which increase the natural supply of groundwater and prevents the severe drop in groundwater levels. In this study, suitable areas for artificial groundwater recharge are identified in an aquifer located in Gorveh-Dehgolan Plain using geographic information system (GIS) and analytical hierarchy process (AHP). To achieve this aim; first, the spatial map of seven effective parameters: slope, infiltration, electrical conductivity, alluvial thickness transmissivity, drainage density, and land use were prepared in GIS environment. Next, the maps were weighted using AHP method and overlaid by utilizing GIS analytical function. In next step, the entire aquifer is divided into five areas, each in different sub-basins, and finally the best region for artificial recharge, was selected. The degree of suitability for locating artificial recharge is also shown by mapping the selected region into four classes suitable to unsuitable. Furthermore, in order to evaluate the sustainability status of water resources for the study area, planning for sustainable use index (PSUI) is calculated for current state and for the status of implementing artificial recharge using precipitations with various return periods. This index is based on the water balance parameters which can sufficiently demonstrate impacts of applying artificial groundwater recharge on water resources sustainability including surface water and groundwater. The results of this study show the significant value of utilizing analytical techniques in evaluating the level of artificial groundwater recharge.

The public water systems (PWSs) across the U.S. utilize either groundwater, surface water, or groundwater under the direct influence of surface water (GWUDI) resource, treating the source-water to applicable federal primary and secondary drinking water regulatory requirements and standards and, thus, distributing to residential, institutional, commercial, and industrial users. The PWSs in the U.S. are required by federal requirements—based on 40 CFR Part 141, Subpart O—to provide the annual water quality reports, consumer confidence reports (CCRs), to their customers. The source water quality, selected water treatment train, and the product drinking or potable water quality at distribution are critical elements of water supply, at all times. This presentation is focused and included (as feasible): a review of the Year 2016 CCRs on drinking water production and distribution in the fifty-three (53) capital cities of U.S. and territories and, a discussion of the data reported on source-water and product water quality parameters. The current presentation and reporting of CCRs have been observed to be not uniform and comprehensive. A recommendation is made toward preparing and providing the descriptions and data in the CCRs, as per the applicable requirements, in a uniform manner for the comprehensive understanding of stakeholders.

Despite high precipitation, large aquifers, and rivers Lebanon has recently experienced a shortage of potable water. This problem can be attributed to population growth, the high number of refugees, and inadequate water management. Lebanon’s water management policies have led to random and poorly managed water extraction from aquifers with resulting aquifer collapse and shrinking or disappearing streams. Studies were conducted in several areas (i.e., Batroun, Tarshish, and Kfarnabrakh) to determine the viability and quality of Lebanon’s water resources. Site testing and geologic maps in Batroun showed a meocene m2 formation (a semi-aquifer) with a 200 m thickness above sea level. The audi-magnetotelluric (AMT) method showed water shortage with salt water intrusion below seawater level. Depth and water quality studies will be conducted on another aquifer in this area to determine if it can provide potable water. A hydrogeological study in Tarshish showed the presence of four geologic formations: J6, C1, C2a, and C2b. AMT data indicated the presence of four layers, consistent with the data obtained from the hydrogeological interpretation of the section. Based on this formation it was determined three productive aquifers could be accessed with different water potential by drilling 70 m, 250 m, and 750 m into the C2b, J6, and J4 layers respectively. AMT soundings were carried out in Knaisseh using Stratagem EH4. A geophysical survey showed layers with dissimilar lithostratigraphic properties and corresponding depths. The AMT results corresponded with the geological cross-section showing three water-bearing layers (i.e., C2a, C1, and J6) with different resistivity zones. C1 and J6 were determined to be potential aquifers.

Excessive nitrate loads from intensive agricultural and pastoral production have been led to groundwater pollution in many groundwater-dominated urban and rural in North China, especially in semi-arid grassland. Hydro-geological units and watershed-based nutrient reduction planning have been proposed for the impacted grassland ecological system in Inland River Basin all around the Inner Mongolia, in China. Taking Damao County as typical area, an integrated modeling approach was developed to simulate and predict the nitrate loads and the temporal and spatial distribution characteristic of nitrate concentration in the different representative sub-units during 2013–2016, then the concentration of nitrogen is estimated that accounts for long-term nitrate storage in the aquifer and losses from the recharge to the discharge zones. The calibration and verification statistics and sensitivity analysis show that the model can provide accurate nitrate concentration predictions for watersheds in semi-arid grassland that is a suitable tool for controlling the nitrate emission. The result shows that annual nitrate losses, including aquifer long-term storage, transport, biological uptake, and discharge were estimated to be 0.65 mg N L^-1, corresponding to 3.00 kg N ha^-1. The total nitrate loads from unsaturated zone to the shallow aquifer were predicted to an optimal emission concentration range between 0.35 mg N L^-1 and 1.29 mg N L^-1 under varies nutrient reduction planning in Damao grassland.

Heavier saltwater overlies fresh groundwater in many estuaries. It has been shown in the case of the Swan-Canning Estuary in Australia that unstable conditions occur if the anisotropy ratio is relatively small. An unstable condition causes salt fingers to migrate from the estuary into the underlying aquifer which can result in significant salt transport from the estuary into the aquifer. This study examines the effect of the anisotropy ratio on the transport of salt from the Indian River Lagoon (IRL), an estuary on the east-central coast of Florida, into the unconfined aquifer. The coupled model SEAWAT was used to examine the salt transport from the IRL to the underlying unconfined aquifer at two transects, Eau Gallie and River Walk. The model investigated the effect of anisotropy ratios between the range of 10 and 1000. The lateral hydraulic conductivity at the two transects was 20 m/d, and 13 m/d, respectively. Results showed that the condition remained stable and no fingering occurred in either transect when the anisotropy ratio was 150 or higher. The magnitude of fingering increased significantly as the anisotropy ratio decreased. An anisotropy ratio of 10, which is typically used in numerical models, showed considerable fingering. A key conclusion is that it is important to know the correct anisotropy ratio prior to modeling as arbitrarily selected anisotropy ratios can lead to highly erroneous results related to salt transport.

An unstable condition occurs as a result of heavier saltwater in an estuary overlying the freshwater in the underlying aquifer. This could result in significant salt transport from the estuary into the aquifer. Groundwater salinity was measured at the Eau Gallie and River Walk transects below a coastal estuary known as the Indian River Lagoon (IRL) to determine the temporal and spatial extent of salt transport from the IRL into the aquifer. These transects extend from the mainland to the Atlantic Ocean or the Barrier Island and are 3.1 km and 1.6 km long, respectively. Measurements were taken on five occasions between June 2014 and September 2015. During this period, the IRL salinities in the Eau Gallie and River Walk transects varied from 0.53 to 0.79 (ocean salinity=1), and from 0.58 to 0.90, respectively. The groundwater flow into the unconfined aquifer below the transects is primarily freshwater (salinity=0.0833) from the mainland and flows upward into the IRL. At each transect, salinity measurements were made at 16 wells at depths of 1 m to 3 m below the lagoon bed. The inverse distance weighted interpolation (IDW) method was used to create iso-salinity contours below the IRL at both transects. These contours showed that the groundwater salinity changed with the IRL salinity indicating that salt from the IRL was moving down into the aquifer and mixing with the upward moving freshwater from the mainland. This salt transport should be accounted for in the hydrodynamic models of the IRL.

Lack of sufficient observed data exerts challenges to proper calibration and evaluation of predictive ability of groundwater models. In this paper, the use of interpolation of observed hydraulic heads for improving the calibration and evaluation of groundwater models at two transects across the Indian River Lagoon Estuary, has been investigated. Additional synthetic head values were obtained from the interpolated head surfaces. Numerical models were developed using SEAWAT code. Statistical measures used to evaluate the calibration results included: 1) root mean square error (RMSE), 2) Nash-Sutcliffe efficiency NSE index, 3) two-sided t-test, and 4) visual comparisons head contours below the lagoon. Calibration by RMSE was found to be misleading since relatively small RMSE values were obtained even with poor calibration. The effect of adding the synthetic interpolated observations on improving the calibration results was more obvious in the trnasect that has smaller width compared to the other transect that has larger width and has the same number of actual observations used. Both NSE and t-test calibration statistics improved significantly by using the interpolated observations in the larger transect. However, these two measures did not have effect on the results of the smaller transect. Results of this work suggest using interpolation to provide calibration targets in situations where limited field data is available for model calibration and evaluation.

The standard L-moment based regional frequency analysis (RFA) involves four steps: data screening, identification of homogenous region, selection of distribution, and estimation of associated parameters. This study augments the last two steps of RFA using Bayesian statistics in order to limit the subjectivity of distribution selection and account for parameter and model uncertainty. Bayesian model averaging (BMA) was employed along with multiple performance measures to combine distributions and provide a consensus prediction that avoids subjectivity and quantify modeling uncertainty. The differential evolution adaptive metropolis (DREAM) algorithm, the latest addition in MCMC sampling, was adopted to estimate parameters of selected distributions and quantify parameter uncertainty. The results based on extreme precipitation data from 85-station and 10-duration in Eastern U.S. suggest that the coupled BMA and DEARM delivers a less subjective prediction with a better performance than the single best distribution as measured by Taylor diagram, Anderson Darling, and Bootstrap efficiency measures.

Weather generation models based on multivariate censored distribution (WG-MCD) and multivariate autoregressive censored process (WG-MACP) have been developed and presented in the paper entitled “Stochastic Simulation of Daily Precipitation at Multiple Sites: I Model Development”. In this paper, the performance of these models is evaluated by comparing discrepancies in attributes (e.g., mean, variance, correlation) obtained from the historical and simulated precipitation. Precipitation records from years 1961–1990 at ten climatic stations located in Manitoba, Canada, are adopted for the performance evaluation of models. Three performance measures (i.e., the coefficient of determination, the coefficient efficiency, and the root mean square error) identify a fairly strong relationship between the historical and simulated precipitation. Proposed models has been found to be suitable for reproducing the statistical characteristics of daily historical precipitations at multiple sites. The spatial and temporal dependencies appear to have been reasonably captured by the covariance and lag-1 covariance of the WG-MACP model. Other descriptors, such as probabilities of wet/dry-day, mean values, and variances, show good statistical agreement with similar statistical characteristics of the historical and simulated data sets. It was found that a better performance of the model could be obtained with use of a smaller number of stations, and with less number of statistical attributes to be preserved.

Rapid urbanization caused significant land use/cover (LUC) changes in the city area, this conversion caused runoff coefficient increasing, which impacted the water availability changes. Detecting runoff coefficient change is the requirement of smart city water management. Traditional lumped hydrological model could not be used for this purpose because its model could not be adjusted with the changed LUCs. Distributed hydrological model derives model parameters directly from terrain properties, thus have the potential to be used to estimate the runoff coefficient changes. In this study, a method is proposed to estimate the flood event runoff coefficient changes which dividing the study area into irregular cells based on satellite remote sensing imagery, and calculate the runoff production by employing the runoff production modular of Liuxihe model. In this study, the Liede Creek, a small watershed in the center of Guangzhou City with a drainage area of 18.70 km² and a length of 6.35 km, was case studied. Changed LUCs increased the runoff coefficient, thus worsening the urban flood and caused more flood damages. In this study, the LUCs change series of Liede Creek in Guangzhou City in the past 30 years has been collected and post-processed, which are used to drive the Liuxihe model for runoff production calculation. Three observed precipitation in recent years was collected to make the runoff production simulation. Flood event runoff coefficient changes have been detected, which shows it is a big change in the past decades.

Drought is a natural calamity, occurring due to less than average rainfall over a given period of time at given space which consequently leads to short-term water deficit and economic loss. The drought characteristics refer to frequency, severity i.e. magnitude of deficiency, and its duration. In this study long term monthly rainfall records for the period from 1901 to 2013 for all the 93 districts of central India covering the states of Andhra Pradesh, Telangana, Tamil Nadu, Karnataka, and Kerala has been used in the analysis. The percentage departures of annual and seasonal rainfall from corresponding average have been used for the identification of onset and termination, and quantification of severity of drought events. The study revealed that the average return period of drought in major part of southern India are in the order of 5–9 years except in the state of Kerala and coastal regions of Karnataka where the return period found to be more than 10 years. The central, north west, and south east part of the region faces the frequent drought of once in 5-6 years while the northern part and some parts of western Tamil Nadu experienced the drought with the return period of 7–9 years. There are only 3 districts (Chamrajanagar, Erode, and Coimbatore) where the average return period of drought is 4 years. The maximum rainfall deficiency in region had been found to be 66% of average annual rainfall for Nellore District which is rare. The coastal region experienced the maximum deficiency in the order of 30–45% of average annual rainfall i.e. severe drought are rare in the coastal region. The extreme drought events are very rare in the southern India. There have been numerous persistent drought events of 2-, and 3-, consecutive years found in the study. On the basis of this study various drought risk management in the Southern India can be applied.

Mesoscale convective systems (MCSs) are large clusters of thunderstorms that act as a single system generating localized extreme precipitation and causing disastrous flooding and destruction in the central United States. To enhance our modeling of such storm events, especially under future climate projections, this study focuses on modeling MCSs through the use of the weather research and forecasting (WRF) model running in the simulation mode, i.e., without any nudging or other data assimilation techniques. In this study, the WRF model is run using several combinations of the different model parameterization schemes and is used to reconstruct an intense historical MCS over the Midwestern United States. The simulation results are then compared to the observation. The model’s performance is evaluated through the use of a few statistical tests as well as a visual comparison, and the best simulation is chosen based on the statistical tests as well as the location, intensity, and texture of the simulated storm event. From this exercise, we find that the WRF model, running in the simulation mode, has the capability of reproducing intense historical MCSs relatively well over the Midwestern United States under the appropriate model parameterization scheme combination.

In August 2017 Hurricane Harvey made landfall on the Texas coast. Several locations near the coast reported precipitation total depths in excess of 50 inches, the largest ever recorded rainfall depth in the U.S. from a single storm. Probable maximum precipitation (PMP) estimates using the procedures outlined in National Oceanic and Atmospheric Administration (NOAA) Hyrdrometeorological Reports (HMRs) have been used to determine design basis flooding events for nuclear power plants, dams, and other risk significant facilities throughout the United States. This paper investigates precipitation depths at several locations in southeastern Texas during Hurricane Harvey and compares them with PMP estimates from the NOAA HMRs at existing nuclear power plant locations along the U.S. Gulf Coast. The results of this comparison indicate that Hurricane Harvey precipitation depths, although are higher than the depths previously recorded are, nonetheless, lower than PMP depths used to determine design basis flooding at the U.S. nuclear power plants.

The aim of this research is to find out an effective method for forecasting drought in Dhaka using El Nino-Southern Oscillation index. Long lead drought forecasting method will be beneficial as timely information about the onset, extent, intensity, and duration of drought can limit losses to economy and environment. With this view, the strength of teleconnection between drought indices SPI, SPEI, and ENSO index (sea surface temperature) was assessed by performing correlation analysis, which shows a strong correlation between average SPI, SPEI values of month October-November-December (OND), and OND SST of NINO 3.4 region for the period 1994–2014. Then discriminant analysis has been performed to evaluate the possibilities of a long lead drought forecast and it was found that droughts are more likely associated with El Nino which is the warm episode of ENSO whereas during La Nina probability of occurrence of wet event increases.

The purpose of this study is to reconstruct atmospheric conditions over Ishikari River Basin (IRB) in Japan during a historical period. Although observation data of near-surface atmospheric variables including precipitation are available for at least several decades in Japan, they are not sufficient to analyze causes of precipitation over IRB. Therefore, in this study, atmospheric conditions over IRB were reconstructed by means of dynamical downscaling with a regional climate model. As a regional climate model, weather and research forecast (WRF) model was employed. ERA-interim reanalysis data were used for initial and boundary conditions of WRF. As the first step of the reconstruction, the model options of WRF were configured by try-and-error. After the configuration, atmospheric conditions over the IRB were reconstructed during 1980–2011. Then, basin-average precipitation over IRB between the reconstructed results and the corresponding observations for the whole period were compared for the validation. This presentation shows the configuration and validation results as the preliminary results.

Located along the western coast of Turkey, the Gediz Basin counts on agriculture as its most important economic activity. Over the last few decades, the basin has been facing water-related problems, such as water scarcity and competing use of water. However, an investigation of possible future water demands and droughts is expected to be helpful for water managers dealing with the future water planning and management of the region. As such, this study aims at evaluating the future water balances occurring in the major reservoir of the basin during the 21^st century. For this purpose, four future water supply projections are generated using a hydro-climate modeling framework. This framework includes the coupling of a regional climate model, the weather research and forecasting (WRF) model, and a fully physically-based hydrologic model, the watershed environmental hydrology (WEHY) model, under two IPCC representative concentration pathway scenarios (RCP4.5 and RCP8.5) of a CMIP5 global climate model, HadGEM2-ES. A dynamic water balance model is, then, developed to carry out reservoir simulations and is used to operate the reservoir with the projected future flowrates in order to identify water deficits or surpluses under the projected irrigation water demands for the years between 2015 and 2100.

The estimation of extreme design rainfalls in the context of possible climate change impacts (CCIs) has become essential in current engineering practices due to recent recognition of climate variability. This estimation requires hence a new rainfall modelling approach that could establish an accurate linkage between climate projections from global or regional climate models and observed extreme rainfall processes at a local site. Furthermore, outputs from these climate models are mostly available at the daily timestep because of current limitations on detailed physical modelling and computational capability. Hence, rainfall data of high temporal resolutions are often limited or unavailable at the location of interest while those of daily scale are widely available. Recently, statistical models based on the scale-invariance (or scaling) concept has increasingly become a new modeling tool since these scaling models could be used to derive short-duration extreme rainfalls based on those of longer durations. Therefore, the main objective of the present study is to propose a novel scaling GEV/PWM model for modeling extreme rainfall process over a wide range of time scales (e.g., several minutes to one day). The feasibility and accuracy of the GEV/PWM model was assessed and compared with the three existing popular models using IDF data from a network of 21 raingages located in Ontario, Canada. Results based on different statistical criteria have indicated the superior performance of the proposed GEV/PWM as compared to these existing models. The proposed model was used for constructing IDF relations for Ontario using climate projections from different climate models.

In the present study, long term historic changes in precipitation and aridity index (AI) was examined for the period of years 1901 to 2013 at 21 hydro-meteorological stations over Betwa River Basin, part of Uttar Pradesh and Madhya Pradesh states of Central India. Modified Mann-Kendall test was applied for detecting the long term trend and to deal with the condition of serial correlation in time series of precipitation and aridity index. Further, Sen’s slope estimator was employed for estimation of slope. AI was calculated for various seasons using formula recommended by United Nations Environment Program. The results revealed that some of the hydro-meteorological stations exhibited increasing trend of precipitation and AI during pre-monsoon season. During monsoon season two stations (Banda and Narsinghpur) exhibited decreasing trend of AI with slope of -2.45×10^-3 and -2.74×10^-3, respectively due to increase in potential evapo-transpiration (PET), however, no significant trend was observed in precipitation. During post-monsoon season, no significant trend in precipitation as well as AI was observed. During winter season, only one station (Bhopal) exhibited increasing trend with slope of 0.05 mm/year and 11.84×10^-5 for precipitation and AI, respectively. On yearly basis, only one stations (Banda) exhibited decreasing trend of precipitation with slope of -1.25 mm/year and two stations (Banda and Hamirpur) exhibited decreasing trend of AI with slope of -55.9×10^-5 and -60.35×10^-5, respectively. The results of this study is useful for understanding the behavior of drought conditions in the study area.

Watershed modeling facilitates informed water resources management. Understanding the magnitude and timing of hydrologic fluxes, and natural and anthropogenic processes that govern water availability is key for allocation of limited water resources to competing sectors in arid regions. In this study, soil and water assessment tool (SWAT) is applied to model an agricultural watershed facing water resources challenges in a portion of the Middle Rio Grande Basin located in the New Mexico-Texas-Mexico border region where agricultural activities rely on conjunctive use of surface water and groundwater supply. The model is calibrated and validated under baseline conditions in the arid climate to evaluate potential impacts of climate change. Climate change scenarios are based on downscaled temperature and precipitation projections and projected inflows to Elephant Butte Reservoir, the main surface water source in the region. Simulation of key components of the regional water budget, including stream flow, evapotranspiration, and recharge improves understanding of regional water availability under climate change. The model is useful for exploring the impact of different water and land management strategies to cope with extreme climatic events.

The objective of this study is to forecast streamflows in the Chixoy River Basin, Guatemala. The basin covers an area of about 5,000 km², it is located upstream of the Usumacinta River which drains into the Mexican Gulf, and it was selected as case study because it supplies the main hydropower plant of the country. Based on teleconnection principles and linear multiple regression analysis, statistical models were performed. The independent variables were oceanic and atmospheric indices used for monitoring El Niño South Oscillation (ENSO) by the National Weather Service/Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA). These variables include sea level pressures (SLP), southern oscillation index (SOI), sea surface temperatures (SST), and trade winds (TW) in different regions of the Tropical Pacific Ocean, as well as autocorrelation of the river flows. The dependent variable was the seasonal (three-monthly average) river flow into the hydropower reservoir Chixoy for the period 1980–2009, which was operated by the Guatemalan National Electrification Institute (INDE in Spanish). The models were assessed through multiple step-wise regression analysis and cross correlations lagged from 1 to 12 months. To appraise the forecast potential of the model, cross validation was performed where the correlation coefficient, the difference between the forecast and the observed river flow, and the standard error were evaluated. In addition, the Durbin-Watson test was applied to verify that there was no autocorrelation on residuals. Six models were developed for the trimesters September-October-November (r²=0.803); October-November-December (r²=0.748); November-December-January (r²=0.818); December-January-February (r²=0.800); January-February-March (r²=0.820); and February-March-April (r²=0.855).

Disinfection of water by exposure to sunlight is an age-old concept. Historically, as a religious practice, copper containers filled with water were left in sunlight for hours to make it potable. In the last century, a renewed interest to develop sustainable water disinfection concepts for under developed communities has been revived. Many research studies incorporate water treatment systems involving both thermal and optical inactivation of bacteria. Progress focuses on increasing the effectiveness of systems by adopting improved reflector surface materials and shapes. Water depth and suspended solids are primary factors which impact the penetration of sunlight. Reduction of suspended solids can be achieved either by sedimentation or filtration. Filters comprised of natural material can make the system sustainable and reduce costs. To investigate the performance of such a water treatment system, a pilot water treatment plant using no fossil fuels was designed and tested. The plant consists of filters using natural materials, solar panels to operate a pump for moving water from the source, a natural stream in a highly urbanized area to the plant, and reflector basins to gather and focus natural sunlight for disinfection (SODIS). A reflective circular-section open channel was adopted for optical disinfection by sunlight. The study indicates an inverse relation between flow rate and disinfection rates. The pre-disinfection filters contributed to a reduction in bacterial concentration of the resulting water, and this form of SODIS was successful in achieving the minimum 30-day average E. coli concentrations necessary for recreational water access.

Designing sustainable urban water infrastructure requires consideration of hydrologic and hydraulic performance (H&H) and the life cycle assessment (LCA). Although LCA (ISO 14044) has been widely used for the sustainability assessment of a variety of infrastructure and products, its application in water resources is limited. The objective of this paper is to present a method of integrating H&H and LCA criteria into the evaluation of the environmental sustainability of urban water infrastructure. This method serves as a decision support system for analyzing stormwater control infrastructure. Rainwater harvesting (RWH), a trending decentralized urban water infrastructure, showcases the application of the proposed method in this paper. Results show that without using an integrated method, life cycle impacts are noticeably underestimated. The integrated method provided broader information on stormwater control strategies, and indicated the strengths and weaknesses of each scenario.

Environmental issues are at the center of the global agenda. The development dynamics of contemporary society is not compatible with the capacity to generate resources on the planet. This requires a reorientation of production models and current patterns of consumption. With regard to this theme, the World Commission on Environment and Development, indicate the need to include environmental issues in decision-making processes within the political and developmental framework of society. On this point, when taking into account studies by the International Council of Societies of Industrial Design (ICSID), which indicate that about 80% of the environmental cost of a product, service or system is generated in the design phase. This demonstrates the importance of design education with a sustainable approach. However, it is not possible to say that this approach is being done properly. It is from this premise that this work tries to investigate how the Brazilian higher education institutions, deal with the environmental problems in their undergraduate courses in design.

Desalination is a drought-resistant alternative for freshwater generation, especially for arid southwest with history of recurring droughts. With growing population and changing climate, water demands in the region are increasing, thus desalination becomes an effective option to supplement limiting freshwater resources. A major barrier to desalination is its high energy consumption and associated cost. Using renewables as an energy source for desalination has the potential to make it less costly and more sustainable. Las Vegas Valley is underlain by a shallow brackish groundwater aquifer with total dissolved solids levels varying from 1,000-10,000 mg l^-1. The objective of this study was to determine the potential of using solar photovoltaic (PV) for pumping and desalination of a brackish shallow groundwater for a selected well in Las Vegas Valley. Brackish water pumping and desalination system using reverse osmosis was designed using industry-accepted criteria, and the corresponding energy consumption was determined. System advisor model was used for performance and economic assessment of solar PV. Energy consumption was shown to be largest for concentrate management, utilizing about 94% of the overall energy consumption. A 5.5 MW solar PV, with battery bank capacity of 255 MWh was found to be viable with positive net present value of $2.6 million. Reduction in carbon emissions due to PV deployment was found to be 4,700 metric tons CO₂eq year^-1. The methodology used in this study can be applied to other regions for sustainable inland desalination of brackish groundwater.

Mesoscale hydrological models are required for suitable assessment for prediction of runoff in larger catchments. The objective of present study is to evaluate the performance 2D MIKE SHE model coupled with MIKE SHE/MIKE 11 including the overland flow and channel flow processes in Burhanpur catchment (area of 8995 km²), part of Upper Tapi Basin, India. The Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) 30 m topographical data, gridded rainfall (0.25⁰×0.25⁰) data, station based potential evapotranspiration (PET) and IRS P6 LISS-III satellite data of year 2000 (used for land use classification) were taken as distributed input into the model. The model parameters were calibrated on grid size 500 m×500 m using stream flow data of flood year 1994, and further, validated for independent data of flood years 1998 and 2007. The model performance was quantitatively assessed using statistical indicators, RMSE (=168.3– 175.7 m³/s and 20.5–15.9 mm), NSE (=0.69–0.68 and 0.89–0.87), and r (=0.78–0.77 and 0.96–0.94) on daily as well as monthly time scales respectively, during calibration and validation periods. The calibrated model would be useful for prediction of runoff and stage along Tapi River at Hathnur Dam, India.

Broad Channel is located within Jamaica Bay in the Borough of Queens in New York City. This community experiences several days of coastal flooding each month, based on the lunar cycle. The perigean spring tide and storm events only compound the flooding. Rising sea levels (over 1-foot in the last century) continue to worsen the problem. With global climate models (GCM’s) that continue to predict an increased rate of sea level rise over the coming decades the outlook for this coastal community was bleak. Although urban coastal communities will always be at risk, street elevations below tidal water elevations and inadequate coastal protection exacerbate the problem.

This paper presents a study on sediment in Texas reservoirs and its effect on reservoir firm yield. This study examined the geographical variation of reservoir sedimentation across the State of Texas as well as the sediment distribution inside a reservoir at all depths from streambed to the top of conservation pool. Results indicate that sediment accumulates faster in lower elevations than in higher elevations in most Texas reservoirs but the opposite is true in reservoirs where significant deltaic formations exist. Reservoir elevational sedimentation rates (capacity loss rates) are estimated incrementally at different elevation levels to develop reservoir rating curves according to the vertical distribution of sediment, using the data from hydrographic surveys. Reservoir rating curves for the next 50 years are predicted, assuming a constant sedimentation rate for the prediction period. Based on the predicted rating curves, reservoir firm yields for the prediction periods can be estimated and a relationship between predicted reservoir capacity and firm yield is derived. This provides useful information for water planning in Texas.