Walid Elshorbagy | UAE University (original) (raw)

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Papers by Walid Elshorbagy

Résumé/Abstract Water consumption by crops can drop below the potential values under conditions o... more Résumé/Abstract Water consumption by crops can drop below the potential values under conditions of limited irrigation water supply. The deficit in irrigation supply can be reduced by official reuse of drainage water when mixed with irrigation water at specific known locations. If the amount of this reused water does not meet the deficit, farmers tend to use low quality water from randomly selected points at the nearby drains, unofficially.

Abstract The use of numerical modeling in oil spill incidents is a well established technique tha... more Abstract The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model.

ABSTRACT United Arab Emirates (UAE) is characterized by scanty and erratic rainfall and high leve... more ABSTRACT United Arab Emirates (UAE) is characterized by scanty and erratic rainfall and high levels of temperature and eventually evaporation. This paper discusses the integration and sustainability aspects observed in designing the different water systems in urbanized coastal areas in UAE with a focused reference to a new development currently undertaken in Dubai. The developed area hosts one of the largest international airports in the world in addition to several residential, commercial, and recreational developments.

With the growing concern on coastal environment, the focus on coastal hydrodynamics in the Arabia... more With the growing concern on coastal environment, the focus on coastal hydrodynamics in the Arabian Gulf region has been growing in recent years. A numerical model is used to study the flow dynamics along the coast of the UAE. For complete understanding of the circulation pattern, the modeling is done for the entire gulf. The model employs a curvilinear grid system with sigma layers in the vertical direction. The tidal model boundary is located at the east on the Straits of Hormuz where the principal tidal constituents are introduced.

ABSTRACT This study is an extended and comprehensive analysis to accomplish optimal sizing for a ... more ABSTRACT This study is an extended and comprehensive analysis to accomplish optimal sizing for a biological nutrient removal (BNR) system with an A 2 O BNR activated sludge process using activated sludge models (ASM) kinetic models. A highly nonlinear activated sludge model combined with the EAWAG Bio-P module is formulated and optimized using a generalized reduced gradient solver. Primary and final clarifications are included with the A 2 O biotreatment scheme along with oxygen-supplying units.

Abstract A hydrographic survey was conducted to measure the salinity and temperature in the south... more Abstract A hydrographic survey was conducted to measure the salinity and temperature in the southern shelf of the Arabian Gulf in summer and winter seasons. The data provides salinity and temperature fields that complement the physical data available in other literature. Salinity values as high as 46 ppt were found near the coastal Ruwais site located approximately 230 km west of Abu Dhabi, the capital city of the United Arab Emirates.

Situated within the richest oil area in the world, the Arabian Gulf represents a stressed ecosyst... more Situated within the richest oil area in the world, the Arabian Gulf represents a stressed ecosystem with scarce published data and environmental studies.< p>< br>< br> The oil-related activities cause significant damages to different ecosystem components such as coral reefs, algal mats, mangrove and other habitats.

Calibration of a water distribution network is intended to develop a model that mimics field cond... more Calibration of a water distribution network is intended to develop a model that mimics field conditions under a range of demand distributions. In this paper, a three-step calibration procedure is developed that considers the uncertainties in measurement and estimation and provides a measure of the quality of the calibration. The approach can also be used to identify preferable conditions for data collection. The procedure's steps are parameter estimation, calibration assessment, and data collection design.

The operational and accidental oil pollution is a major challenge in the RSA. The impacts of offs... more The operational and accidental oil pollution is a major challenge in the RSA. The impacts of offshore installations of oil and gas particularly those of produced water on the marine environment in general and in shallow waters or near to ecologically sensitive areas in particular are noticeable. The operational pollution from ships and dumping of ballast water are also among the main causes of chronic oil pollution in the Region.

The future operations of many engineering systems are affected by the uncertainty of many inputs ... more The future operations of many engineering systems are affected by the uncertainty of many inputs and demands. To account for these elements of a two-stage stochastic programming, formulation is proposed and illustrated for several engineering problems concerned with water distribution and supply. In all of these applications, the first-stage decisions are the design elements that are to be determined at present.

Studying and understanding the hydrodynamic conditions of the Arabian Gulf have received growing ... more Studying and understanding the hydrodynamic conditions of the Arabian Gulf have received growing interest over the last few decades. This is attributed to the strategic importance of the area, as it is used in transporting most of the oil produced from the Gulf countries in addition to being the main source of desalination water that such countries rely on heavily. Yet, only few comprehensive studies have been conducted to fully characterize and interpret the hydrodynamics of the Arabian Gulf. The current study is one of those efforts directed towards the understanding of water dynamics in the Arabian Gulf. This has been achieved by virtue of three-dimensional numerical modeling supported by field measurements conducted recently in the southern shelf to verify the output results. The southern shelf refers to the southern region of the Arabian Gulf, bounded from the west by the Qatar Peninsula and from the south by the United Arab Emirates. The utilized numerical model employs a rectilinear grid system with parallel layers and uses explicit technique in solving the continuity, momentum, and heat/solar-transferee governing equations. The model employs typical seasonal wind fields developed via combining Hellerman historical data averaged over the last 30 years with other data recorded recently in the southern shelf. Salinity and temperature fields are also incorporated in the simulation model, considering the Mt. Mitchell National Oceanic and Atmospheric Administration data complemented with field measurements in the southern shelf. The conducted field measurements include tidal records at three stations and current measurements at one station and are found to reasonably agree with the simulated results.

1102/JOURNAL OF HYDRAULIC ENGINEERING/DECEMBER 2002 avalanche face slope mostly conforms to the a... more 1102/JOURNAL OF HYDRAULIC ENGINEERING/DECEMBER 2002 avalanche face slope mostly conforms to the angle of repose in laboratory conditions Ogink 1988. However, field measurements show that the avalanche face angle is lower than the angle of repose Ogink 1988; Barua and Dey 1996. In the case of the Brahmaputra/Jamuna River in Bangladesh, the angle varied between 3.7 and 32.8 with a mean of about 11.9 Barua and Dey 1996.

Résumé/Abstract Nowadays, an activated sludge process is the most commonly used biological wastew... more Résumé/Abstract Nowadays, an activated sludge process is the most commonly used biological wastewater treatment process. In addition to its cost-effective properties in removing the organic material form wastewater, it is flexible, reliable, and has the capability of producing high quality effluent. Advanced models simulating the complex biochemical reactions taking placejn activated sludge reactors have been progressively applied in many process fields.

The US Safe Drinking Water Act and its amendments impose restrictive rules for filtration of surf... more The US Safe Drinking Water Act and its amendments impose restrictive rules for filtration of surface water and maximum contaminant levels for total trihalomethanes (THMs) in distribution systems. Extension of these regulations can potentially address the possibility of limiting each individual THM compound since the health risks associated with these compounds are not all alike. Current models of THMs are predicated on empirical reaction kinetic equations derived from linear and nonlinear multiregression analysis.

Abstract A three-dimensional numerical modeling study is done to simulate the face of benzo (a) p... more Abstract A three-dimensional numerical modeling study is done to simulate the face of benzo (a) pyrene, a carcinogenic poly aromatic hydrocarbon, in the dynamic coastal environment after its release from a refinery outfall. In the model, pollutants are distributed in the water, organic carbons, and sediments according to specific chemical laws. In the water column, it is subject to transportation, settling and losses. Processes of burial, resuspension, bioturbation, and losses regulate its kinetics in the sediment layer.