Assessment of groundwater vulnerability to pollution in Barrax, Albacete, Spain

An integrated approach with the generic and agricultural DRASTIC models as well as a Geographic Information System was used to assess groundwater vulnerability in the agricultural area of Barrax, in the province of Albacete, Spain. Depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone media, and hydraulic conductivity of the aquifer were considered as weighted layers to enable an accurate groundwater risk mapping. The generic DRASTIC model indicated very low vulnerability to contamination for Barrax groundwater because of limited urban and industrial development in the wider area. However, agricultural activities impose pressure on groundwater resources. The agricultural DRASTIC model indicated that 5.41% of the study area is characterized by very high, 3.54% by high, 32.73% by medium, 49.45% by low, and the remaining 8.86% by no vulnerability to groundwater contamination. The distribution of nitrate concentration in groundwater in the area under study is correlated with the agricultural DRASTIC vulnerability index. This study demonstrates that the integrated approach enables the assessment of groundwater vulnerability in agricultural areas and provides new opportunities for predicting groundwater contamination on different spatial scales and categories of the environmental quality. Therefore, it is very useful for policy makers for the design and selection of preventive and remedial measures.