Spatial variations and trend analysis of groundwater salinity along coastal aquifers of Mundra-Kachchh over a decade—using thematic maps and GIS mapping

Abstract

Abstract Water is one of the most basic entities, especially in semiarid regions where low precipitation and limited surface water resources bring more emphasis on the use of groundwater leading to endangering and overexploitation. Therefore, quantity with monitoring of groundwater quality at regular intervals becomes of utmost importance for understanding its suitability for drinking and irrigation. This study aims in understanding spatial variations and their trend in terms of quality over a decade (2010–2020) using different hydrochemical parameters in the vicinity of the coastal tracts of the Mundra block. Samples were analyzed for TDS, pH, EC, TH, major cations, and anions. Drinking suitability was identified by correlating parameters with WHO, BIS standards and by preparing WQI maps. Irrigational suitability was found by SAR, RSC, KI, Na %, MH, and PI. Reduced water level (RWL) values represented a further increase in the reversal flow of groundwater in a decade leading to an increment in salinity and seawater intrusion. The study area in most of the analysis is possessing much higher values above safer limits when compared to 2010 and 2020, making the water very much unacceptable for drinking and irrigation. The major cause in the area is overexploitation and unconditional deeper drilling, resulting in an increase in coastal salinity and seawater intrusion. The use of such water tends to harm agriculture, soil condition as well as human health.

Keywords

• Semi-arid
• Spatial variations
• Salinity
• Coastal aquifer
• Kachchh