Groundwater Quality Assessment Using GIS for Agricultural Propose in Molakalmur Taluk, Karnataka

Abstract

Objectives: To assess the carbonate concentration in relation to calcium and magnesium concentrations and to determine TDS and sodium concentration in relation to other cations. The study’s overall goal is to examine the suitability of groundwater for irrigation/agricultural purposes in Molakalmur Taluk of Chitradurga District, Karnataka, India. Methods: The current study was carried out to analyze the water quality and spatial distribution of physicochemical parameters of groundwater in study area. A total of 92 groundwater samples were collected during the pre-monsoon period; ArcGIS 9.2 was used to create a spatial distribution map based on a geographic information system. The concentrations of various ions like Ca+2, K+1, Cl-1, Mg+2, HCO3 -1, Na+1, CO3 -2, and SO4 -2 were evaluated as per BIS 3025 (2014) and compared to various irrigation standards like Sodium Adsorption Ratio (SAR), Percentage of Sodium (%Na), Magnesium Adsorption Ratio (MAR), Kelley’s Ratio/Kelly’s Index (KI), Permeability Index (PI) Electrical Conductivity (EC), Total Hardness (TH), Total Salt Concentration, Chloride in irrigation water and integrated standards such as USSL and Wilcox diagram. Findings: During the pre-monsoon period, the majority of the samples in the study area fell into the hard to very hard water category. According to Evaluated water quality indices like SAR, MAR, PI, KI, SSP, Cl and total salt concentration around 5 to 15 percent water samples are not good for agricultural purpose and as per the integrated parameters like USSL and Wilcox the percentage samples that are unsuitable for irrigation is going up to 30 percentage due to presence of higher Electrical conductivity. Novelty: In the study region, there is no perennial river and the main ion chemistry of Molakalmur Taluk’s groundwater has never been investigated before. The present work attempts to study the suitability of water for agricultural purpose. The findings of the study will aid in the collecting of crucial data on groundwater quality in Molakalmur Taluk. The findings of the study could also help groundwater managers and urban planners to restore and improve groundwater quality. Keywords: Physicochemical parameters; Irrigational water quality; Salinity hazard; Alkalinity hazard; Geographic Information System