Spatial Variation of Surface Water Quality of Vrishabhavathi Watershed Using GISÂ

Vrishabhavathi Watershed is a constituent of the Arkavathi River Basin, Bangalore Urban and Ramanagara District and covers an area of 381.465Km2, representing seasonally dry tropical climate. In Vrishabhavathi watershed Vrishabhavathi River is the main surface water source which is tributary of river Arkavathy, which joins the Cauvery River. It drains a major parts of Bangalore metropolis and is an outlet for domestic and industrial effluent of that area. Earlier this surface water is mainly used for agricultural purposes and drinking purposes. Since this watershed lies in Bangalore urban and Bangalore rural area, today this water is only used for agricultural purposes which are also not safe. In order to assess the surface water quality the present study has been undertaken to map the spatial variability of the surface water quality in the watershed using Geographical Information System. The water qualities of 24 stations were randomly selected in Vrishabhavathi watershed for the present study.GIS is an efficient tool for representation and analysis of spatial information related to water quality analysis. The spatial variation map for sensitive water quality parameters are generated and integrated using Arc GIS10.1. The final integrated map shows 3 priority classes such as Acceptable, Poor and Very poor water quality zones of the study area and provides a guideline for suitability of water for irrigation purpose