Hydrochemistry of the Natuf drainage basin : Ramallah / West Bank

Abstract

The Natuf drainage basin in the western hills of Ramallah district is about 200 km2. Many springs emerge in the area from perched aquifers and outcrop from limestone and dolomite limestone formations. This study aims to add more information about hydrochemical parameters and the chemical changes in spring water between dry and wet seasons and to locate possible sources of pollution and their effect on the water quality of water from the springs for domestic and agricultural uses. The study involved collection and analysis by conventional and available instrumental methods for the hydrochemical parameters from 12 springs before and after recharge. Water samples of runoff from two places in eastern and western parts of the study area were collected and analyzed as well. Most of the springs in the study area are of good water quality for domestic and agricultural uses. Variations in the chemical composition between dry and wet seasons, and from one spring to another, were observed. Springs near densely populated areas and agricultural activities show higher values of EC, SSP, SAR and TH. Also uncountable colonies of faecal- and total coliform were detected. Trace amounts, within World Health Organization (WHO) and the Palestinian standard limits, of cadmium, chromium, cobalt and lead are found in some springs; while concentrations of iron and zinc that were detected in springs near populated areas are higher than other springs. Water types of Ein Musbah, Al Alaq and Ein Arik El Tehta are of earth alkaline with increased portion of alkalis with prevailing bicarbonate and chloride in wet and dry seasons. Other springs show a variation in water type between earth alkaline with prevailing bicarbonate in the wet seasons to earth alkaline with prevailing bicarbonate and chloride in the dry seasons.