Evaluation of groundwater quality and depth with respect to different land covers in Delhi, India

Groundwater properties vary spatially and temporally with number of factors. In the present study, an attempt has been made to study the groundwater characteristics of Delhi with respect to different land covers. Four land covers were selected viz. protected forest, trees outside forest, maintained park and settlement area with two sites under each type of land cover. Groundwater quality and depth were found out for each site. Water samples were analyzed and compared with BIS drinking water standards and were used to determine water quality index (WQI). Chemical analysis revealed that Delhi groundwater is hard (120–1120 mg/L) and slightly alkaline (pH 7.32–8) in nature. Values of TDS and hardness were reported to exceed desirable limits for more than 50 percent samples. Sites under protected forest area were found to have least WQI values indicating good water quality. Minimum groundwater depth was reported from settlement area sites while contrary to this maximum water depth was reported from protected forest area sites. Groundwater depth was found negatively correlated with chemical parameters.