Abstract:
Located in a region known for its scarce water resources, The Litani River Basin, totally contained within Lebanons borders, is endowed with significant water resources that have been at the centre of Lebanons water supply, agriculture and hydroelectric development plans. However, many years of civil strife and foreign occupation compounded with proliferation of uncontrolled urban, agricultural and industrial growth have taken their toll on the quality of the basins surface water and potentially its groundwater quality conditions. This paper reports on findings from a study with the objective of assessing groundwater quality conditions in the Upper Litani Basin (ULB) based on data collected through an extensive water quality survey funded by the USAID as a component of its initiative to support local government efforts to manage water quality conditions in the country. The data is composed of two sampling sets representing summer and winter conditions and include several key water quality indicators. The paper focuses on the methodology and results of a geostatistical analysis of the sampled groundwater nitrate concentrations. The analysis produced two sets of georeferenced nitrate concentration and probability of exceedance maps representing winter and summer conditions. The results indicate a significant, widespread and persistent nitrates contamination of groundwater in the ULB. Nitrate levels in groundwater exceed standard limits for drinking water in many parts of the basin.