GIS based groundwater quality mapping and analysis in southern part of Anuradhapura District

Abstract

Groundwater is the major drinking water source in the world. More than 90% of the rural population use groundwater for drinking and other domestic purposes. Presently the agriculture, urbanization and industrial processes have direct and indirect effects on Groundwater distribution and its quality. This study was conducted in Horivila and Palugaswewa in the southern part of Anuradhapura District. In this area the main groundwater source is well water and there are both tube wells and dug wells. Dug wells were monitored for present research to identify groundwater distribution and quality variations. The initial study revealed that within the study area more than 100 dug wells were available but only less than 10 wells were using as drinking water due to high salinity. The objective of this investigation has been to identify and assess the suitability of ground water quality for drinking purpose through water quality index investigation of the well water. The pH, Electrical Conductivity (EC), salinity, Na, K, Ca, Ma, Fe and Cl in groundwater of the study area was analyzed by collecting groundwater samples from 100 wells using the 100 * 100 meter Grid. The mapping and spatial analysis carried out in the study using Arc GIS 10. Muchof the well water in the study area are not acceptable for drinking purposes in respect to chemical aspect. However, in fewer locations Ca+2, Mg+2 and Cl-1 has been exceeded the recommended levels of water quality given by WHO.