Spatial variation of groundwater quality of Meham block of Rohtak district, Haryana

Water is most vital input in agriculture and can be optimally used only when its quality is assessed at micro level. The present study was aimed to assess and categorise the quality of groundwater of Meham block of Rohtak district by focusing on spatial variability of electrical conductivity (EC), pH, cationic and anionic composition of the groundwater. It was revealed that 75% of the samples showed EC values upto 3 dSm"¹ and the maximum value of EC was found as 7.34 dSm"¹. Groundwater of south-eastern part has lower EC as compared to the other parts of the block. Residual sodium carbonate (RSC) and sodium adsorption ratio (SAR) varied from nil to 6.30 me L"¹ and 5.18 to 30.76 (m mol L"¹)², respectively. Cl" and HCO₃" were found in appreciable quantities, whereas, CO₃"² were in traces. Contour maps of EC, pH, SAR, RSC and quality of groundwater in the block were plotted through GIS to study spatial variability of these parameters. According to AICRP classification, it was found that 22.9% waters were of good quality, 45.8% saline and 31.3% sodic in nature. Out of the saline water, 20.8, 6.3 and 18.7% were marginally saline, saline and high SAR saline, respectively. In alkali group, 12.5, 6.3 and 12.5% were marginally alkali, alkali and high alkali, respectively. On the basis of spatial variability analysis, maximum area (25.4%) of the block was found under marginally saline category.