An integrated GIS and hydrochemical approach to assess groundwater contamination in West Ismailia area, Egypt

Groundwater is a very important resource across Ismailia area as it is used in domestic, agricultural, and industrial purposes. This makes it absolutely necessary that the effects of land use change on groundwater resources are considered when making land use decisions. Careful monitoring of groundwater resource helps minimize the contamination of this resource. This study developed a GIS-based model to assess groundwater contamination in the West Ismailia area based on its hydrochemical characteristics. The model incorporated five different factors which are standardized to a common evaluation scale. The produced factor maps include the depth to the water table, the potential recharge, the soil type, the topography, and the thickness of saturation. These maps are combined in ERDAS Imagine, ARC INFO, and ARC GIS software using geostatistics and a weighted overlay process to produce the final groundwater potential risk map. The model output is then used to determine the vulnerability of groundwater to contamination by domestic, agricultural, and industrial sources. The produced risk maps are then combined with the groundwater contamination potentiality map using an arithmetic overlay in order to identify areas which were vulnerable to contamination. The results of this study revealed that the groundwater is highly vulnerable to contamination that may result from the inappropriate application of agrichemicals and domestic and industrial activities. The produced integrated potential contamination maps are very useful tools for a decision maker concerned with groundwater protection and development.