الفهرس 
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Abstract
The present study deals with evaluation of water resources of some catchments in El-Tur area. The study area is located in the southwest part of Sinai Peninsula, Egypt and covers about 9000 km2. It lies between latitudes 28º 00’ and 28º 35’ N and longitudes 33º 30’ and 34º 00’ E. On the other hand, it is bounded by the Gabel El-Qabaliat in the West, basement rocks to the North, and Ras Gara, to the South, basement rocks to the East and Gulf of Suez to the West. It lies within the hyper arid zone. Its climate is hot in summer and scarce rainy in winter.
At El-Tur meteorological station the maximum and minimum humidity values recorded in December and June were 38% and 0% respectively. The relative humidity increases from north to south and east to west. Generally, the relative humidity plays an important role in the intensity of evaporation, evapotranspiration and dew condensation and accordingly, increases the rate of deterioration in the ecosystem. Rainfall is scarcely occurred and showing wide variability from year to year. Rainfall is occurred from October to March. The highest total annual rainfall (21 mm/year) is recorded at Sant Katherine meteorological station, followed by Suez meteorological station (17mm/year), Abu Rodaus meteorological station (13 mm/year), El Tur meteorological station (8 mm/year).
Geomorphologically, the surface of southwest part of Sinai Peninsula was discriminated into the following three geomorphic units; the eastern mountainous region , the western sedimentary hills, and the central plain.
Geologically, in the southwest of Sinai, the surface is occupied by Pre-Cambrian, Paleozoic, Paleocene, Eocene, Miocene, and Quaternary deposits. The Quaternary deposits cover the study area. Structurally, El Tur area is dissected by the main faulting and folding system which takes many directions. The first direction is NW– SE (the direction of Gulf of Suez), while the second direction is NE–SW (the direction of Gulf of Aqaba) and N- S directions. These faults are responsible for the formation of block faulting structures, i.e. grabens and horsts. El Qaa plain is one of those blocks, located along the eastern side of the Gulf of Suez graben.
Hydrologically, the hydrological setting in the study area was discussed under the three topics, basin characteristics, surface hydrology and groundwater hydrology. Basin characteristics include the study of the 25 morphometric parameters. The statistical analysis of these parameters was carried out including R-mode and Q-mode. In addition, the relative hazard degree was estimated for every studied basin. The infiltration rate of the soil cover for every basin was studied through carrying out 11 infiltration tests using double ring infiltrometer.
Surface hydrology includes the study of precipitation characteristics and the rainfall-runoff relationship. Precipitation characteristics were discussed depending on the records from six raingauge stations installed during this work. Monthly rainfall depth during 2002-04 was recorded and the records till 2009 were downloaded from NASA website. The spatial distribution of seasonal and monthly rainfall, the intensity of rainfall, the recurrence interval and probability, and the frequency of rainfall were discussed in this work. The rainfall-runoff relationship for every selected basin was estimated applying the United States Soils Conservation Service method, 1972 (SCS curve number model).
Groundwater hydrology includes the study of the Quaternary aquifer water bearing zones. The Quaternary aquifer is composed of sand, gravels and sand dunes and includes three water bearing zones. The best water bearing horizon is the first layer (gravely sand), in particular at the increased depth of this layer at the north and central parts of the plain. Thickness of the Quaternary aquifer ranges from 10 m to 60 m and generally increases towards the south. The groundwater exists under free water table condition in the majority of El Tur-Ras Gara area at depth varying from 11 m to 60 m below ground surface. The occurrence of clay and silt intercalation in the lower layer renders it to function as semi-confined aquifer. The groundwater flows generally from NE to SW direction.
The salinity of the groundwater in the Quaternary aquifer in El-Tur area ranges between 4383 ppm to 23753 ppm. Different groups of salt assemblages are formed as shown:
I -NaCl, Na2SO4, NaHCO3, Mg(HCO3)2 and Ca(HCO3)2 as 7% .
II-NaCl, Na2SO4, MgSO4, Mg(HCO3)2 and Ca(HCO3)2 as 7%.
III-NaCl, Na2SO4, MgSO4, CaSO4 and Ca(HCO3)2 as 59%.
IV-NaCl, MgCl2, MgSO4, CaSO4 and Ca(HCO3) 2 as20%.
V-NaCl, MgCl2, CaCl2, CaSO4 and Ca(HCO3)2 as7%.
The genesis of groundwater mineralization refers to primary salinity (73%) as a result of the effect of clay lenses and lagoonal deposits present in the study area. The secondary salinity is characterized to 20 % of the analyzed samples.
The assessment of water resources in El-Tur area was discussed through assessment of both surface and groundwater resources. The assessment of surface water runoff is achieved via applying SMADA model for generating catchment hydrograph of the seven selected basins. The input data for SMADA model are watershed characteristics, rainfall data, the infiltration and initial abstraction losses and time of concentration. The output of the model includes the hydrograph time parameters like time to peak and lag time beside peak flow. In addition, direct runoff volume was estimated applying f-curve method and rational method. Also, the runoff coefficient was estimated to use in water harvesting model. The proposed location of different dams required for water harvesting in the studied basins was presented.
The assessment of groundwater resources was discussed in traditional method due to the lack in input data required for applying suitable mathematical model. Moreover, the groundwater recharge rate is estimated as it is a prerequisite for efficient groundwater resources assessment. In this study, two methods for estimating groundwater recharge were chosen depending on the available field data, the stream-flow infiltration method and the chloride mass balance method.
The optimum exploitation and use of water resources were presented in this study depending on the rank and weight of the following effective hydrologic parameters; groundwater table, diffusivity coefficient, groundwater salinity, chemical water type and land use.
CONCLUSION
Results obtained in this study lead to the following conclusions concerning the conditions, procedure and suitable modes of utilization for the EI-Tur water resources.
i) Present domestic and agriculture water requirements in EI-Tur area are satisfied through groundwater from EI-Tur Quaternary aquifer. The annual was estimated as 1.75 million m3.
ii) Using the information of 2000, agriculture water requirements in 1994 was estimated at 0.30 million m3/year. The pipeline implemented to deliver a 0.73 million m3/year to Sharm EI-Sheikh dose partly satisfy tourism requirements.
iii) The maximum possible water demand for agriculture sector may reach 27.4 million m3/year by year 2010 if land suitable for agriculture purposes are utilized. The total demand is expected to reach 30 million m3 by the year 2010. These forecasted demands are based on the evaluation of detailed assessment of the government policy, population growth and per capita consumption.
Surface Runoff
i) The average maximum flow rate resulted from daily rainfall storm of 28.5 mm which recurs every 20 years, ranges from 90.8 m3/s (Wadi Abu Garf) to 572.2 m3/s (Wadi Selly) while it ranges between 66 m3/s (Wadi Abu Garf) and 646.5 m3/s (Wadi Selly) based on the hydrograph analysis generated from the same daily rainfall storm.
ii) Based on the analysis of the data collected from the seven selected catchments in El-Tur area, some of the results related to hydrological behavior in basement terrains around the area of study can be elucidated as follows:
*The runoff coefficient ranges from 0.89 % to 7.8% depending on the duration and intensity of rainy storms.
* The threshold rainfall producing runoff is 7 mm.
iii) Reliable estimate of the surface runoff in El-Tur may be obtained through the application of SMADA model. Calibration of SMADA results with the f-Curve model and Rational model indicated great agreement between the simulated runoff volumes and the estimated ones by the other two models.
iv) Based on the analysis of the recorded storm of 07/02/1999, and the adopted model, the average peak flow was estimated to range between 90.8 and 572.2 m3/sec, with average of about 5 million m3/year.
v) The results of Water Harvesting model show that under rainfall storm of 25 mm depth the C/CA ratios ranges between 7.92 and 28.94. This means that the catchment area reproduces surface water runoff volume satisfying for cultivating 4969 Feddan (20.87 km2) with wheat.
vi) The flood harvesting from the studied basins assumes maximizing the utility from total surface runoff approaching 5 million cubic meters. This can help in settlement of Bedouin people by construction of small irrigation communities (1 Feddan/family x 50 families x 5000 m3/Feddan x 20 years = 5 x 106 m3).
Groundwater
i) The groundwater conditions in the study area was included in the present work. Well locations, and temporal and spatial variations of salinity are discussed.
ii) The groundwater recharge was estimated by analyzing the temporal and spatial groundwater samples in wells and rainfall. It was found that the total annual recharge from the eastern wadis is approximately 7 million m3/year.
iii) Recharge equations developed based on suggested recharge, indicated that 40% of rainfall in excess of 7 mm constitute recharge for basement aquifers.
iv) The total recharge to El-Tur plain was estimated as 4 million m3/year. The overall recharge represents about 16 % from the median rainfall of the study area (23.9 million m3/year). At present time, approximately 6 million m3 are wasted to sea every year.
Water Utilization
i) The groundwater in the study area is unsuitable water for drinking due to their high salinity range (4470 – 23782) mg/l. All groundwater samples in the study area are considered as hard water, i.e., unsuitable for laundry use. In addition, satisfactory water for livestock (TDS: 3000 – 5000 ppm) includes well no. 15 only. The groundwater in the study area is suitable for irrigating salt tolerant crops. It was found that, net return of using the water for agriculture is 1.4 LE/ m3 while it is 4.4 LE/m3 in tourism at Sharm El Sheikh.
ii) Abstraction Areas
The different parts of the study area were ranked according to groundwater salinity, hydraulic conductivity, saturated thickness, diffusivity and land potential. Based on these factors, a map was developed to define the most suitable zones for well installations.
RECOMMENDATIONS
Development in agriculture should be limited in EI-Tur plain area. High evapotranspiration rate, high wind speed, spatial distribution of the water quality in addition to lack of adequate maintenance, are the major contributing factors to low return in agriculture activities and more depletion to the aquifer.
* Projection of water demands are far from the resources evaluation. Planning should be based on an integration of all resources and should take into consideration the limiting natural conditions. Decision makers should plan relying on scientific guidance not on the dreams.
* It is recommended to drill new productive wells in the area east of El-Tur city at depths not more than 100 m to preserve the natural balance between the fresh water and the underlying saline water.
* Further hydrogeophysical and hydrological investigations are needed to determine the groundwater occurrences and their extensions in the area located to the southeast of El-Tur city before any agriculture sustainable development.
* Observation and test wells are required for continuous monitoring of the groundwater levels in the study area. Periodic collections of water samples from already drilled water wells for chemical analyses are highly recommended.
* The distance between every two adjacent drilled wells in El-Gobail village, Ras gara village and El Tur area should not be less than 1 km and far from the Gulf of suez shoreline by 2 km in order to minimize the interference between fresh water and saline water.
* The development of groundwater source must be regulated within the recharge limit. If there is no regulations, users are likely to damage the water supply. Over-exploiting the groundwater supply may deteriorate the groundwater quality as a result of excessive pumping or gulf water intrusion. Thus, there is a need for imposition the water legislations to control the development of groundwater.
* It is recommended to expand the methodology presented herein for the recharge estimation to similar arid catchments.
* Detailed modeling activities should be conducted for the area to investigate the impact of long term pumping on salt water intrusion and water quality.
* The data sets collected from the seven selected catchments of the eastern hydrographic basins were used extensively in the present work. Such data proved to be very useful for both the analysis, understanding and development of valuable relations for ungauged catchments. It is thus highly recommended to increase the number of such catchments both in Sinai and in the other Egyptian deserts.