Groundwater quality assessment of Allahabad smart city using GIS and water quality index

Abstract

Groundwater quality plays a very important role in groundwater protection as well as demarcation of the groundwater depleted area which may be attempted for its improvement and conservation. An effort has been made to comprehend the water quality of Allahabad city with the help of groundwater sampling, their chemical analysis, and synthesis of results in GIS framework. The assessment of physiochemical parameters of groundwater samples for drinking purpose has been made using Water Quality Index and Geographic Information System. Spatial distribution of pH, electrical conductivity, total dissolved solids, fluoride, iron, total alkalinity, total hardness, chloride, sulphate, sodium, potassium, calcium, magnesium, bicarbonate, and nitrate content of groundwater samples collected from 12 locations and studied for pre-monsoon (May 2016) and post monsoon (Nov 2017) periods has been assessed using Arc-GIS. Water quality maps of pre-monsoon period reveal that 4.23% area is falling under good, 74.82% under moderate, and 12.12% under poor and 0.66% under very poor category while water quality maps for post monsoon period reveal that the 40.33% of area falls under good, 58.89% area under moderate and 0.77% under poor water quality. The observed values of various physiochemical parameters of water samples were also compared with standard values recommended by IS 10,500:2012. It is observed that depth to water has positive correlation with TDS, electrical conductivity, and hardness. The extent of pollution occurred in the city is due to over exploitation of groundwater, urbanization, and anthropogenic activities.