Evaluation of Groundwater Quality Index in Greater Visakhapatnam Municipal Corporation,Andhra Pradesh using GIS and Laboratory Methods

An integrated approach of geographical information system (GIS), global positioning system (GPS) and water quality index (WQI) studies has been effectively used for identifying the spatial distribution for quality of groundwater zones in Greater Visakhapatnam Municipal Corporation (GVMC), a coastal city of Andhra Pradesh state. Physico-chemical analysis was carried out for various selected parameters such as pH, alkalinity, electrical conductivity (EC), total hardness (TH), calcium hardness (CaH), sodium (Na), potassium (K), chlorides (Cl), sulphates (SO $_4$ ), fluorides (F) and indirectly estimated parameters like total dissolved solids (TDS), magnesium hardness (MgH), carbonates plus bicarbonates (CO $_3$ +HCO $_3$ ) by adopting standard methods and compared with the Bureau of Indian Standards (BIS). The analytical results revealed that most of the groundwater was found to be in polluted category. The GIS analysis of spatial distribution map of the overall water quality index revealed that only nine percent of groundwater during pre-monsoon and around sixteen percent in post-monsoon is suitable for drinking purpose.