Vol. 22 Issue 3
Firyal Bou-Rabee
Strong seismic events along the seismically active Zagros Fold Belt can have damaging effects in Kuwait and other Arabian Gulf countries. A comprehensive seismic risk and vulnerability assessment of infrastructure systems, in particular tall structures and coastal facilities is needed. Evidence is presented which indicates a potential threat from large-magnitude earthquakes originating from the southern part of Zagros, at moderate epicentral distances from Arabian Gulf cities. Observations of seismic paleo-liquefaction features in the Gal-Az-Zor escarpment (Kuwait) are presented and discussed. The historical record of Iranian earthquakes that have caused significant ground motion in the Gulf region is examined, as well as reports of coastal damage from tsunamis. There are specific tasks that give validity to having a Regional Center for Risk Research in the Arabian Gulf countries.
Muhammad A Al-Zahrani
Water quality monitoring of the distribution system is important in controlling and ensuring that safe water will be delivered to the consumers' taps. The Safe Drinking Water Act requires that water quality in a water distribution network be sampled at locations which are representative of the whole network system. Presently, no guidelines exist describing how these sampling locations are identified. In this paper, a methodology based on Genetic Algorithm (GA) is introduced and applied to a real water distribution network. A prior step before applying the developed method is to simulate the flow within the distribution system. For this purpose, a hydraulic simulation model called EPANET was used. Once the simulation of the water distribution system is performed, the developed GA method is then applied to identify locations of water quality sampling stations for the water distribution network of Al-Khobar City in the Eastern Province of the Kingdom of Saudi Arabia. Final results indicate that the selected water quality monitoring stations identified by the developed model are mostly located in areas within the city where water consumption is very high. The results obtained are compared with the current practice of identifying water sample locations and show more confidence over the current practice.
H.A. Ibrahim, A.H. El-Hussini, R.E. Fat-Helbary, N.A. Kasyanova and M.O. Ebraheem
A geophysical investigation has been conducted in the Abu Simbel region using the D.C. resistivity method. The results have been integrated with geological information in order to determine, where possible, the depth to the basement, any water-table variations, and the delineation of the hydrogeologic conditions. In this study, twenty vertical electric soundings (20 VES-es) were measured in the area. The measured geoelectric data were made utilizing different configurations (Schlumberger and Wenner) using an ABEM-Terrameter SAS300c resistivity meter. The sounding data were interpreted and analyzed by using classical curve matching and modern computer techniques. Interpretation of each curve model provides the equivalent layering in the form of n-layers with different thicknesses and true resistivities. The presence geoelectric zones with different geographic distribution. The wet zone (50 - 500 Ohm) is lying at a shallow depth with varying thickness (1- 24m) and formed as lenses. Three highly resistive lying near the surface and is made up of ferruginous sand which is an obstacle to the growing of bushes in the new farming desert lands and the third (deep) may correspond to hard rocks (e.g, basement rocks), Seven surface water samples from Khors of Lake Nasser were analyzed in the years 1999, 2000 and 2001. These samples were taken from different locations around the lake adjacent to Abu Simbel town. The hydrochemical analysis of these samples illustrated that the values of TDS and trace elements are nearly the same. It is observed that the values of TDS and trace elements increase only at the sites near the denser population communities.
Mahmoud Said Al Yamaini
A computer-based rainfall-runoff Hydrologic Modeling System (HEC-HMS) was used to determine the approximate hydrologic response of seven major sub-basins that contribute to the main channel of Wadi Fatimah watershed, situated in the western part of Saudi Arabia. The hydraulic response results, which include flood peak discharges, lag time and volumes of flood and sediment load transported by flood waters for different return periods of 10.25.50 and 100 years with storm duration of 1 hour are estimated. On the other hand, as an example, the hydraulic response results and resulting flood hydrographs of the seven sub-basins for the storm of 25 year return periods are presented. These results show that the largest flood volume, which is 3.2 million cubic meters would expect to be produced at Ash Shamiyyah sub-basin (SUB2) with flood peak discharge 975m3/s and a lag time of 5.6 hours, while the smallest one (1.98 million cubic meters) with lag time of 2.7 hours and runoff peak 120m3/s was estimated at the outlet of Wadi Azzibarah sub-basin (SUB3). The flood volume of the entire basin was 73.3 million cubic meters with runoff peak at the outlet of about 1550m's and lag time of about 12.1 hours. However, the values of flood peak discharge and volumes of floods as well as sediment loads increase for storms of longer return periods. The outcome results of this work may provide valuable information that can help in water work constructions to prevent and/or reduce the flood damages that take place within the study area.
Ahmed I Rushdi, Khalid Al-Mutlaq and Bernd RT Simoneit
Soil and sand dust resuspension is one of the major input mechanisms of harmful anthropogenic substances into the atmosphere of arid regions. Pesticides and herbicides are the major components of these toxic substances in soils of agricultural regions. This research examines the occurrence of pesticides and herbicides in soil and sand dust from various locations in the city of Riyadh, Kingdom of Saudi Arabia. The organic components, including pesticides, herbicides, fossil fuel residues, and natural lipids were analyzed by GC-MS for this area to define their sources and strengths. The results show that various pesticides and herbicides are present in soil and sand dust in Riyadh City and include Carbofuran, Chlorpyrifos, Oxadiazon, Ethoprophos, Dimpylate, Iso-Octyl-MCPA, Methyl dichloro fop, Endosulfan I and II, and other unknown derivatives. Anticorrosive reagents such as 1-chlorododecane and 1- chlorotetradecane and plasticizers are also significant compounds in these samples. The occurrence of pesticide and herbicide residues in most of the samples from the city is due to activities related to agriculture. Local agriculture and gardening applications of these pesticides are suggested to be the main sources of these compounds in soil and sand dust of the city. The presence of chloro-n-alkanes is attributed to contamination from anti abrasion-antiwear lubricating oils used for protecting petroleum production equipment. The occurrence of plasticizers in these samples is attributed to tyre and plastics abrasion products. n-Alkanes, UCM and series of hopane and sterane biomarkers were also detected in these samples. The n-alkanes, ranging from C1 to C36 maximum abundances at various carbon numbers, hopane biomarkers and UCMS support the input of particles from vehicle emissions and the excess n-alkanes with odd carbon number preferences, as well as methyl n-alkanoates indicate natural vegetation sources.
Khaled Saeed Balkhair
Water resources conservation is no less important than the strategic role of the agriculture sector. It aims to minimize the food demand gap and achieve self sufficiency through production with existing facilities and capabilities. This study is the evaluation of five crops grown economically under conditions of groundwater supply shortage. It further calculates the possible water savings under two production policies. The study was conducted at the Agriculture Research Station that belongs to King Abdulaziz University in the Makka region. Linear programming was used as a mathematical model in the economic evaluation process. The station's historical records of production and expenses have been utilized during model formation. Two production policies were adopted under the conditions of water availability and water shortage. These are open and restricted production policies. Consequently, the mathematical model was built containing appropriate objective function and constraints for each policy. Optimal production and income was obtained by solving the linear programming problem. Sensitivity analysis was conducted and the effect of objective function coefficient and available resources on the solution was determined and water savings were also calculated. An open production policy leads up to 58% of water savings and achieved 32% more income than the restricted production policy. Results also showed that shortage of groundwater supply in both policies leads to direct reduction in income. A linear relationship was obtained between them.
Meshael Mohamed Al-Saud
This paper deals with the application of numerous statistical and mathematical techniques used during a morphometric study that was conducted at Nessah mountain pass. The study focuses on building a Terrain Model (TM)made of two parts: the Digital Terrain Model, which represents the earth digitally, the other being the Terrain Mathematical Model, this model represents the mathematical and statistical functions that correspond with the morphometric study requirements of the valley, and consequently interacts with the digital data via a computer modeling process The research was enhanced, affected and enriched with results obtained from the application of the mathematical and statistical techniques, not only of its field measurements, but also in the analysis. The data was used to determine the various morphometric characteristics, (water, morphic topographical and river density) and to find out the correlation relationships between them that will establish the related planometric drawings. This has been achieved through the following research stages
- Enhancing the field work through the adjustment of Geodesic observation by the least squares
- Assigning correlation power between the meteorology and the morphometric characteristics. Determination of their function significance level via the application of Pearson's correlation equations, and the partial correlation application of the statistical test known as (t Test)
- Detection of the most appropriate equations to represent the scope in the main valley and its feeders by the application of simple and compound regression equations (polynomial until the 4 grade)
- To assign the geodesic, cartisic and local coordinates mathematically, their interconversion within suphroad international basics. the basics of the complete cosines direction to the basic local geodesic reference.
- To establish a morphometric base to extract the various morphometric characteristics (water, morphic, topographical, and river density characteristics). This was conducted by the application of solid, analytical geometry rules to find out the four basic components of such rules, these are the distance, directions, areas and heights.
- To find out the correlation links between relations of the dual and multi morphometric characteristics and nine other characteristics, after specifying which variants are fixed and which are secondary through the alteration between them through partial correlation. The best regression equation between the nine morphometric characteristics have been specified and the mathematics of the matrixes have been employed to determine the basics of the compound regression equations. To specify the equation error used to adjust the morphometric forms. The application of Azimuth rules in distance, directions, accumulative calculations and the specification of the various coordinates in the planometric drawings operations of the mountain pass borders and its main course and its feeders.