Geoenvironmental study of alluvial aquifer in Upper Gangetic plain, a case study of J P Nagar, Uttar Pradesh, India

Abstract

Water quality is very important if we take into account the human paradigm in the environment. Groundwater constitutes the 30.1% of the freshwater reserves on earth. Gangetic plains in India have the highest density of groundwater extraction structures. 50 samples were taken in total from J P Nagar district of which there were 3 river water samples and 6 were groundwater samples falling just outside the district boundary. Using statistical and GIS analysis various indices were calculated. WQI or water quality index revealed a zone of high pollution across the district. Hydrochemical plots like Piper, Durov and Chaddha diagram brought out the information about the water type in the area. Mineralogy of the study area shows the dominance of feldspar minerals. Land cover change between 1998 and 2013 has been deciphered from supervised classification of Landsat data of USGS. Groundwater reserves of the Ganga plain are so huge that even the GRACE (Gravity Recovery and Climate Experiment) satellite could detect it from hundreds of kilometres away. Though, its use for Indian scenario is not endorsed by many (1). People in India highly depend upon this reserve because canal system is not so well developed to cater to the huge demand for irrigation, industries and agriculture. This has led to its exploitation at an unprecedented rate than ever before. Over exploitation is readily visible on the ground with the presence of a handpump or tubewell in almost every household of the area. Irrigation puts the groundwater in a cycle that involves interaction with chemicals, pesticides and fertilizers. Thus excessive use of groundwater resource has detrimentally affected its quality and quantity (2). The main factors that control the chemical character of groundwater are the climate and vegetation cover, the mineral composition and physical properties of rock and soil through which the water circulates and the relief of the land surface (3). Further, geochemical processes occurring within the groundwater are responsible for seasonal and spatial variations in groundwater chemistry (4). The present study was performed to cover all the major aspects governing the groundwater chemistry of the region through hydrochemical plots, spatial profile of the region and water quality index. Large number of the samples, collected over the region offer clues to geochemical processing in a comprehensive manner. The study area is a small part of the Ganga plain and includes both newer and older alluvium. In the recent past this area has gone through rapid industrialization and population explosion though it is an agricultural area (5). The ephemeral streams in the area are used for discharging industrial waste that has contaminated the aquifer in this region. In this background the present study was undertaken to comprehensively study the groundwater chemistry of the area. 1.1 Study Area Jyotiba Phule Nagar (J P Nagar) district with an area of 2,249 sq. kms forms a part of the western region of Uttar Pradesh state of India in Northern Ganga plain. Jyotiba PhuleNagar lies between 28°20' north latitudes and 78°40' east longitude. Bijnor district bounds it from northern side while Moradabad bounds it from eastern side. The river Ganga forms its natural western boundary and separates it from Bulandshahr, Ghaziabad and Meerut district. The district is drained by the Ganga and its tributaries namely Sot, Ban, Gangan and Tikta. It lies in the interfluve area between the river Ganga and Ramganga. The area is less diversified in terms of agriculture as compared to the whole state. Sugarcane, oilseeds and other commercial crop like peppermint are cultivated more in this district. 99 per cent irrigation is done through tubewell which are privately owned. Industrially the region is backward with only eight factories registered by 2005-2006. Tubewell and handpumps are the main source of drinking water in this district (6).