Geospatial and Hydrochemical Analysis of Surface Water and Groundwater Quality of Inland Water Bodies for The Region of India Using Interpolation Techniques and Kriging Methods

The water quality in the Indian subcontinent’s surface water and groundwater is deteriorating rapidly. According to the CWMI by NITI Aayog, 70% of India’s water supply is contaminated nationally. Previous studies have focused on evaluating water quality changes at a sub-regional scale within watershed basins and rivers spanning significant cities. This study delves into spatial and temporal data analysis for the Indian River water basin from 2011 to 2019. Surface water samples were collected by regional remote sensing centres, with data managed by the State Pollution Control Board as part of India-Water Resource Information Services under the Ministry of Jal Shakti. A structured data repository was created for laboratory data parameters, including carbonate, bicarbonate, pH, turbidity, electrical conductivity, and other parameters. The analysis focused on Uttar Pradesh and Madhya Pradesh, utilizing interpolation techniques like Kriging and IDW. Such techniques help in minimizing bias in prediction. The Kriging predictor is an "optimal linear predictor", ensuring that every interpolated value is computed to minimize the prediction error at that specific point. A 95% confidence interval was established for Hydrogen carbonate concentration and a 90-92% confidence interval for sodium (Na) and Potassium (K). The validation process showed an R
²
(coefficient of determination) value of 84% for hydrogen carbonate and 82% for sodium and potassium, indicating a robust analysis methodology.