Quantitative and qualitative analysis of groundwater affected by land use change

Abstract

Compared to surface water, groundwater resources are the primary source of water supply in arid and semi-arid regions of Iran, hence the importance of the management of these resources .  In this regard, we assessed the effects of landuse changes on the qualitative and quantitative status of groundwater resources in Eshtehard region, Iran. Through processing and analyzing the satellite images, the region was divided into six different land uses, namely agricultural lands, Haloxylon planted area, bareland, saline lands, rangelands, and urban areas; the maps pertaining to these land uses were then prepared. The ground water table fluctuation was assessed via the quantitative data of wells in the study area during 2000-2014. IDW interpolation method was employed to study the spatial variations of parameters, such as EC, Na, SAR, and TDS; afterwards, the maps related to the qualitative and quantitative changes in groundwater were prepared. The results showed that the rangelands, bare lands, and urban areas increased, and the agricultural lands decreased during the studied period. There was more reduction in groundwater table whereas water quality dropped. Generally, water quality was reduced from west to east, and there was more decrease in groundwater table from south to north. It could be deduced that human and natural factors, particularly over exploitation of groundwater, were the main reasons for these changes.