Research progress of a GIS-based DRASTIC model

With the mature development of Geographic Information System (GIS) and wide use of the DRASTIC (Depth to water, Net recharge, Aquifer media, Soil media, Topography, Impact of the vadose zone and hydraulic Conductivity) model, a GIS-based DRASTIC model has been a main method in groundwater vulnerability assessment. This paper gives an overview of the characteristics of the GIS-based DRASTIC model, analyses the research advances of improved model at home and abroad, including reasonable adjustment of evaluation indices, the coupling of the Analytic Hierarchy Process (AHP) and the fuzzy mathematics theory, and discusses the trends of further research as well.