Integration of surface and groundwater resources for the development of Hamad Basin project     

Nabil Rofail  S. I. Asaad 《Environmental Geology》1989,14(3):173-181

Hamad Basin (166,000 km²) is an extensive basin, inhabited by 219,000 souls. It is located in the arid region within the border of four Arab States: Syria, Jordan, Iraq, and Saudi Arabia. Average annual precipitation depth is 78 mm, falling mostly during winter.Integrated studies of the natural resources, (water, soil, range, and animal) were carried out with other complementary studies to formulate a socioeconomic development plan for the promissing areas within the basin.Modern technologies were applied such as remote sensing, isotope analysis, processing, and documenting of basic hydrogeological data within the data bank system using computer facilities.Results revealed that the output of the natural dry plant production amounts to 2.0 × 10⁶ tons. Animal wealth comprise 2 × 10⁶ head mainly of sheep. Average annual surface runoff is 146 × 10⁶ m³, which could be appropriately exploited in water spreading schemes to improve range. Water lost presently through evaporation from vast flat depression (Khabra) could be conserved through deepening the Khabras, and recharging shallow perched aquifer by surface runoff, which could be mined later.Results of regional geology, partial geophysical studies, and hydrogeological, hydrochemical interpretations have concuded the existance of two main aquifer systems, the first lies within the tertiary and quaternary formations, while the second extends to the mesozoic, and paleozoic. Their yield varies quantitively and qualitively, up to 100 × 10⁶ m³ could be safely drawn annually.One compound pilot project was selected within the sector of each of the four Arab States to test the feasibility of the proposed development program for the promissing areas of the basin.  相似文献   

Natural and human-induced sinkhole hazards in Saudi Arabia: distribution,investigation, causes and impacts     

Ahmed M. Youssef  Hasan M. Al-Harbi  Francisco Gutiérrez  Yasser A. Zabramwi  Ali B. Bulkhi  Saeed A. Zahrani  Alaa M. Bahamil  Ahmed J. Zahrani  Zaam A. Otaibi  Bosy A. El-Haddad 《Hydrogeology Journal》2016,24(3):625-644

Approximately 60 % of the 2,150,000 km² area of Saudi Arabia is underlain by soluble sediments (carbonate and evaporite rock formations, salt diapirs, sabkha deposits). Despite its hyper-arid climate, a wide variety of recent sinkholes have been reported in numerous areas, involving significant property losses. Human activities, most notably groundwater extraction, have induced unstable conditions on pre-existing cavities. This work provides an overview of the sinkhole hazard in Saudi Arabia, a scarcely explored topic. It identifies the main karst formations and the distribution of the most problematic sinkhole areas, illustrated through several case studies covering the wide spectrum of subsidence mechanisms. Some of the main investigation methods are presented through selected examples, including remote sensing, trenching and geophysics. Based on the available data, the main causal factors are identified and further actions that should be undertaken to better assess and manage the risk are discussed.  相似文献   

A thermo‐hydro‐mechanical model for unsaturated soils based on the effective stress concept     

Matthieu Dumont  Said Taibi  Jean‐Marie Fleureau  Nabil Abou‐Bekr  Abdelghani Saouab 《国际地质力学数值与分析法杂志》2011,35(12):1299-1317

A simple thermo‐hydro‐mechanical (THM) constitutive model for unsaturated soils is described. The effective stress concept is extended to unsaturated soils with the introduction of a capillary stress. This capillary stress is based on a microstructural model and calculated from attraction forces due to water menisci. The effect of desaturation and the thermal softening phenomenon are modelled with a minimal number of material parameters and based on existing models. THM process is qualitatively and quantitatively modelled by using experimental data and previous work to show the application of the model, including a drying path under mechanical stress with transition between saturated and unsaturated states, a heating path under constant suction and a deviatoric path with imposed suction and temperature. The results show that the present model can simulate the THM behaviour in unsaturated soils in a satisfactory way. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Stochastic Forecasting Models of the Monthly Streamflow for the Blue Nile at Eldiem Station     

Mohamed A. Elganainy  Alaa E. Eldwer 《Water Resources》2018,45(3):326-337

Egypt is almost totally dependent on the River Nile for satisfying about 95% of its water requirements. The River Nile has three main tributaries: White Nile, Blue Nile, and River Atbara. The Blue Nile contributes about 60% of total annual flow reached the River Nile at Aswan High Dam. The goal of this research is to develop a reliable stochastic model for the monthly streamflow of the Blue Nile at Eldiem station, where the Grand Ethiopian Renaissance Dam (GERD) is currently under construction with a storage capacity of about 74 billion m³. The developed model may help to carry out a reliable study on the filling scenarios of GERD reservoir and to minimize its expected negative side effects on Sudan and Egypt. The linear models: Deseasonalized AutoRegressive Moving Average (DARMA) model, Periodic AutoRegressive Moving Average (PARMA) model and Seasonal AutoRegressive Integrated Moving Average (SARIMA) model; and the nonlinear Artificial Neural Network (ANN) model are selected for modeling monthly streamflow at Eldiem station. The performance of various models during calibration and validation were evaluated using the statistical indices: Mean Absolute Error, Root Mean Square Error and coefficient of determination (R2) which indicate the strength of fitting between observed and forecasted values. The results show that the performance of the nonlinear model (ANN) was much better than all investigated linear models (DARMA, PARMA and SARIMA) in forecasting the monthly flow discharges at Eldiem station.  相似文献   

Discriminating Weathering Degree by Integrating Optical Sensor and SAR Satellite Images for Potential Mapping of Groundwater Resources in Basement Aquifers of Semiarid Regions     

Magaia  Luís André  Koike  Katsuaki  Goto  Tada-nori  Masoud  Alaa Ahmed 《Natural Resources Research》2019,28(3):1197-1215

Natural Resources Research - Unlike in coastal and sedimentary basins, regional-scale exploration of groundwater resources using only geophysical methods is costlier in consolidated rocks such as...  相似文献   

A photometric study of the contact binary XY Boo     

Nabil S. Awadalla  A. Yamasaki 《Astrophysics and Space Science》1984,107(2):347-356

The contact binary XY Boo is observed photoelectrically, and variations of the orbital period and the light curves are indicated. NewBV light curves and those of Binnendijk (1971) and Winkler (1977) are analysed by used of the light curve synthesis method. Combining the derived photometric elements with the spectroscopic elements of McLean and Hilditch (1983), we obtain values of the masses and the radii of the components of the system.  相似文献   

Local scour around spur-dikes   总被引：1，自引：0，他引：1  

Nabil A. Zaghloul 《Journal of Hydrology》1983,60(1-4):123-140

Experimental investigations were conducted to study the effects of upstream flow conditions, sediment characteristics, and spur-dike's geometry on the maximum scour depth and scour pattern around a spur-dike. Dimensional analyses to find different non-dimensional terms affecting the phenomenon were obtained and verified with the help of the experimental data. An empirical formula for the maximum depth of scour was derived and found to be identical in form to the regime equations of Lacey and Blench.  相似文献   

The diffraction of linear waves by a uniform vertical cylinder with cosine-type radial perturbations     

Alaa M. Mansour  A. Neil Williams  K. H. Wang 《Ocean Engineering》2002,29(3):239-259

The interaction of linear waves with a uniform, bottom-mounted, surface-piercing cylinder whose diameter exhibits a cosine-type variation is investigated. Two solution methods are presented. One method is based on a perturbation theory, using a perturbation parameter defined in terms of the surface geometry of the cylinder. The analysis includes terms up to the first-order in this parameter, where the zeroth-order solution corresponds to a circular cylinder. The velocity potentials at the zeroth and first orders are expressed as eigenfunction expansions involving unknown coefficients that are subsequently determined through the cylinder boundary conditions. The second method is based on Green's theorem and gives rise to an integral equation for the fluid velocity potential on the cylinder surface. A comparison between the results of these two methods has proved that they are in good agreement for small values of the perturbation parameter. Numerical results are presented that illustrate the influence of the magnitude and frequency of these perturbations on the resulting hydrodynamic force and the wave runup on the cylinder.  相似文献   

Estimation of ship motions using closed-form expressions   总被引：1，自引：0，他引：1  

Jrgen Juncher Jensen  Alaa E. Mansour  Anders Smrup Olsen 《Ocean Engineering》2004,31(1):61-85

A semi-analytical approach is used to derive frequency response functions for the wave-induced motions for monohull ships. The results are given as closed-form expressions and the required input information for the procedure is restricted to the main dimensions: length, breadth, draught, block coefficient and water plane area together with speed and heading. The formulas make it simple to obtain quick estimates of the wave-induced motions and accelerations in the conceptual design phase and to perform a sensitivity study of the variation with main dimensions and operational profile.  相似文献   

Modeling soil collapse by artificial neural networks   总被引：1，自引：0，他引：1  

Adnan A. Basma  Nabil Kallas 《Geotechnical and Geological Engineering》2004,22(3):427-438

The feasibility of using neural networks to model the complex relationship between soil parameters, loading conditions, and the collapse potential is investigated in this paper. A back propagation neural network process was used in this study. The neural network was trained using experimental data. The experimental program involved the assessment of the collapse potential using the one-dimensional oedometer apparatus. To cover the broadest possible scope of data, a total of eight types of soils were selected covering a wide range of gradation. Various conditions of water content, unit weights and applied pressures were imposed on the soils. For each placement condition, three samples were prepared and tested with the measured collapse potential values averaged to obtain a representative data point. This resulted in 414 collapse tests with 138 average test values, which were divided into two groups. Group I, consisting of 82 data points, was used to train the neural networks for a specific paradigm. Training was carried out until the mean sum squared error (MSSE) was minimized. The model consisting of eight hidden nodes and six variables was the most successful. These variables were: soil coefficient of uniformity, initial water content, compaction unit weight, applied pressure at wetting, percent sand and percent clay. Once the neural networks have been deemed fully trained its accuracy in predicting collapse potential was tested using group II of the experimental data. The model was further validated using information available in the literature. The data used in both the testing and validation phases were not included in the training phase. The results proved that neural networks are very efficient in assessing the complex behavior of collapsible soils using minimal processing of data. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献