تقييم مصادر المياه الجوفيه وخطة حماية حرم البئر في منطقة الفوار
امجد ياسر 'عودة الله' درابيع
AMJAD YASER 'AWDT ALLAH' DARABI
Al Fawwar wells 1 & 2 are major source of drinking water for number of communities like Al- Fawwar camp, Hadeb Al- Fawwar, Al- Higri town and the southern part of Hebron city. The increase in population led to increased water demand and also there is ability to increase the pollution levels. The aim of this study is the delineation of Wellhead Protection Areas (WHPA) for Al- Fawwar wells 1 & 2 in Hebron Governorate due to lack of studies in the West Bank that covers the protection of public drinking water wells from potential sources of pollution by considering the groundwater protection regulation developed by Palestinian Water Authority. It also investigates the potential sources of pollutants that affect the groundwater in the catchment area that extend from Dura at west to Al- Fawwar refugee camp at east, Hebron city at north and Khursa and Tarama villages in south. The lithology of Al- Fawwar wells 1 & 2 was determined by carrying out a geoelectrical investigation by using Vertical Electrical Surrounding (VES). Three main geological formations in the study area were concluded; Hebron formation, Bethlehem formation and Jerusalem formation which consist of dolomite, marl and limestone. The water budget of Al Fawwar wells 1 & 2 catchment was calculated, the area of the wells catchment was about 16 km2 , the volume of: precipitation was 7.93 MCM, water import was 0.438 MCM, evapotranspiration was 5.70 MCM, surface runoff 0.91 MCM, groundwater recharge was 1.84 MCM spring production was 0.354 MCM and a wells abstraction was 0.691 MCM. The evapotranspiration was about 72% of precipitation, the surface runoff was about 11.5% and the groundwater recharge was about 23%. The water loss from precipitation was calculated to be 83.5%. The potential sources of contamination in the catchment determined to include; agricultural lands (use fertilizers and pesticides), lack of sewage network (instead of it, use cesspits to dispose wastewater); for this the groundwater quality of Al- Fawwar wells 1 & 2 was evaluated for domestic purposes. The results show that the concentration of nitrate of Al- Fawwar wells 1 & 2 was (101 and 104 mg/L) respectively, that exceed the acceptable limits of nitrate in drinking water according to iv WHO and PWA standards for drinking water. The results of Fecal coliform (FC) and Total coliform (TC) tests were (zero cfu/ 100 ml) (after chlorination of water) that accepted with WHO and PWA standards for drinking water. The boundaries of Wellhead Protection Area (WHPA) of Al- Fawwar wells were identified using two methods: Calculated Fixed Radius (CFR) and Wellhead Analytic Element Model (WhAEM2000). According to the results of using CFR method for Al- Fawwar well no. 1, the radius of 50 days zone is 51.19 m, for 2 year is 195.6 m and for 5 year is about 309.29 m. For Al- Fawwar well no. 2, the radius of 50 days zone was 38.2 m, for 2 year was 145.8 m and for 5 year was about 230.5 m. According to the results of using WhAEM2000 method for Al- Fawwar well no.1, the travel time parameter (Ť) of 50 days is 0.49, (0.1< Ť < 1), the radius (R) and the eccentricity (δ) is 16.31 m, 5.10 m respectively. For 2 year (Ť) is 7.18, (Ť > 1), the boat shaped radiuses Lu, Ls and Ymax are 149.25 m, 15.77 m, 49.5 m respectively. For 5 year (Ť) is 17.94, Ť > 1, the boat shaped radiuses Lu, Ls and Ymax are 330.53 m, 15.77 m, 49.5 m respectively. For Al- Fawwar well no. 2, the travel time parameter (Ť) of 50 days was 0.93, (0.1< Ť < 1), the radius (R) and the eccentricity (δ) was 12.89 m, 5.2 m respectively. For 2 year (Ť) was 13.55, (Ť > 1), the boat shaped radiuses Lu, Ls and Ymax were 139.7 m, 8.55 m, 26.85 m respectively. For 5 year (Ť) was 33.87, Ť > 1, the boat shaped radiuses Lu, Ls and Ymax were 320.4 m, 8.55 m, 26.85 m respectively. There were violations in the well filed that must prevented after delineation of WHPA of Al- Fawwar wells 1 & 2 like grazing and presence of cesspit in Zone 1. Also there were violations in the boundary of Zone 2 like using of fertilizers and pesticides. By this study, it’s recommended to delineate WHPAs for public drinking water wells mainly by using the WhAEM2000 method.
الدراسات البيئية , Environmental Studies