Different Land Use and other Physical and Socio-economic Parameters in Ground Water Arsenic Concentration

Abstract

An attempt has been made to evaluate how different physical and socio-economic parameter like land use / land cover class, geomorphology, geohydrology and population density impact ground water arsenic concentration of the study area, the district North 24 Parganas, West Bengal, India. In order to accomplish this, overlay and buffering analyses have been extensively performed in a GIS platform. Using supervised classification technique land use/land cover map has been prepared from IRS-1D LISS III satellite image of the study area. In this research a total 80 hydraulic stations (tube well) with their corresponding arsenic concentration value, have been encoded by spatial entity of ‘Point’ on GIS based map of the said district. Half of the encoded hydraulic stations were selected randomly and were categorised into four classes according to their arsenic concentration value. A ring buffer was created around each selected hydraulic station (40 out of 80) with the radial distance of 1km from centre of the ring. The buffered zone was then overlaid on land use/ land cover map to extract the extent of each land use/ land cover class within the buffered zone. A comparative study was made statistically to predict the importance of land cover class to ground water arsenic value of the area. This research confirmed an obvious correlation between ground water arsenic concentration and dominant land use/ land cover pattern of the area. Further those buffered layers were overlaid on digitized geomorphological, geohydrological and population density map of the study area to know whether these parameter have some impact to ground water arsenic concentration or not.