An-Najah Staff

This paper aims to investigate the potential existence of wadi–aquifer interaction in the 320 km2semi-arid Faria catchment using a tracer-based methodology. Faria catchment is located in the northeastern part of the West Bank and accounts for 6 % of the total West Bank’s area. Surface runoff in the catchment consists mainly from springs discharge, runoff generated from winter storms, untreated wastewater effluent from the eastern part of Nablus City and Al-Faria refugee camp, and the return flow from the adjacent agricultural areas. As such, wadi–aquifer interaction may pose serious pressures on groundwater quality which is the only water source for the agricultural and domestic uses in the area. In this study, and in order to investigate the potential existence of wadi–aquifer interaction in the Faria catchment, a tracer-based experiment was conducted. The experiment was carried out using Uranine as a conservative tracer material. A representative reach of 600 m was chosen and was divided into four equal distances. A concentration curve was plotted at each section (monitoring point) with the help of OTIS (solute transport model for streams and rivers) which was used to calibrate the measured concentration curves. Accordingly, the flow rates were estimated at the different monitoring points. The obtained results proved that transmission losses took place in the wadi bed sediments of the selected reach and with different ratios. The percent loss in the flow rates’ values in the different sections ranged from 4.8 to 68.3 %. It was found that the largest transmission losses took place in the section between the first and the second monitoring points. In conclusion, tracer-based methodology is considered as a modern and innovative technique that was used via this research to understand the nature of the wadi–aquifer interaction in Faria catchment and to quantify it as well.

In arid and semi-arid regions, the availability of adequate water of appropriate quality has become a limiting factor for development. This paper aims to evaluate the potential for rainwater harvesting in the arid to semi-arid Faria Catchment, in the West Bank, Palestine. Under current conditions, the supply-demand gap is increasing due to the increasing water demands of a growing population with hydrologically limited and uncertain supplies. By 2015, the gap is estimated to reach 4.5 × 106 m3. This study used the process-oriented and physically-based TRAIN-ZIN model to evaluate two different rainwater harvesting techniques during two rainfall events. The analysis shows that there is a theoretical potential for harvesting an additional 4 × 106 m3 of surface water over the entire catchment. Thus, it is essential to manage the potential available surface water supplies in the catchment to save water for dry periods when the supply-demand gap is comparatively high. Then a valuable contribution to bridging the supply-demand gap can be made.

Arid and semi-arid regions are generally characterized by water scarcity and low per capita water allocation. This situation is further exacerbated when such areas are agriculturally dominated with high-density residential areas. Faria catchment (320 km2), located in the northeastern part of the West Bank, Palestine, is one of these arid to semi-arid catchments where recently, the prolonged drought periods in the catchment and the increasing water demand have made the existing obtainable water resources vulnerable. Catchment drought analysis provides useful information for a sustainable water resources management. In this study, spatial and temporal dimensions of meteorological drought vulnerability in Faria catchment have been investigated using the Standardized Precipitation Index (SPI) as a measure for drought severity. The SPI method was used to detail geographical variations in the drought vulnerability based on frequency and severity of drought events at 1-year time step. This study is applied to rainfall records (1960-2003) for six rainfall stations located within the Faria catchment. Magnitude-duration curves are plotted to depict the relationships between drought duration and magnitude. Critical (threshold) drought values were derived spatially to determine the least amount of rainfall required to avoid from drought initiation. Once drought duration and magnitude have been found objectively, it is possible to use this when manage water resources for bridging the supply-demand gap to drought affected areas either from alternative water resources or from water stored during wet periods.