Geospatial analysis of urban groundwater quality by utilizing gis - a case study in Gampaha district Sri Lanka

Abstract

In Sri Lanka, the need for groundwater is always growing, particularly for irrigated agriculture, the industrial sector, and urban/rural water supplies. According to information from the National Water Supply and Drainage Board (NWSDB), Sri Lanka has 30,000 deep groundwater wells. Shallow karstic aquifers, lateritic aquifers, shallow regolith aquifers, deep confined aquifers, alluvial aquifers, and coastal sand aquifers are just a few of the six main types of aquifers that Sri Lanka has identified. In addition to these aquifers, many groundwater pockets can be found in Sri Lanka. Groundwater in Sri Lanka is about 8 km3 (IGES Freshwater Management Project, 2007). Development and urbanization directly affect the groundwater quality and agricultural, commercial, residential, industrial, and municipal activities contribute to the deterioration of groundwater quality in urban areas. In urbanized areas due to the increase in population, temperature and garbage can be effective for the quality of groundwater and quality of drinking water. As a result of rapid urbanization, groundwater quality can be changed. Gampaha district is the most populous district in Sri Lanka and it is one of the important cities in our country facing significant urbanization and development. Therefore, a comprehensive study of groundwater quality for the Gampaha district is significant. But there is still no comprehensive analysis of groundwater quality in the Gampaha district. Therefore, this investigation supports a comprehensive investigation of the quality of groundwater in the Gampaha district that can be used to further analysis. Hence, water resources in the Gampaha district can be used properly way and can get the real picture of the drinking water quality in the Gampaha district. The specific objectives of this study are to identify major factors that affect the groundwater quality in the Gampaha district and map the spatial distribution of those factors. According to these specific objectives the major objective of this study is to map the groundwater quality in the Gampaha district and assess suitability for drinking purposes using GIS.