Appraisal of Drinking Water Quality of Kalahandi District Using Geospatial Technique

The primary objective of the present research is to assess the effectiveness of geospatial studies in the spatial variation of groundwater quality. QGIS (version 3.14) software is used for geospatial analysis of water quality parameters. Spatial distribution maps of water quality parameters are extracted. Inverse distance weighted (IDW) technique is utilized for the spatial interpolation. Visual interpretation of these maps implies that most of the water quality parameters are well within the permissible limit as per Indian Standard 10,500 (2012): Drinking Water Standard. Weighted overlay map is created by overlaying spatial distribution layers of 13 water quality parameters. Calculated values of groundwater quality index (GWQI) at all stations are similarly interpolated and spatial distribution map of the same is derived. Major portions of the block of Golamunda, Koksara, Dharmagarh, Junagarh and Bhawanipatna the groundwater quality are very poor. The overall water quality ranges within good to medium for most of the regions of the district whereas some of the extreme northern parts of Bhawanipatna and central region of the Junagarh block exhibit excellent groundwater quality. Surprisingly close resemblance between water quality index map and weighted overlay map has been detected. The effectiveness of IDW interpolation is assessed by validating with root mean square error estimates and the value of RMSE is determined very close to 0 indicating that the IDW method has less estimation error. However, IDW over estimates the overall water quality for the present range of data sets.