Identification of Sites Suitable for Artificial Recharging and Groundwater Flow Modeling in Noyyal River Basin, Tamilnadu, India
14 Pages Posted: 30 Mar 2012
Date Written: March 29, 2012
The stress on groundwater resources has become a point of concern for planners and researchers. The groundwater pumping is exceeding the recharge in many areas due to increased dependency on groundwater to cater the needs of the growing population. The assessment of groundwater potential and the identification of areas suitable for artificial recharging in the overdeveloped watersheds are very crucial in reducing the stress on the resources.
Pankaj et al (2000) made a study to identify the groundwater potential zones and found that drainage density and lineaments are the important contributory factors to groundwater recharge. Sarkar et al (2001) conducted a multi-criterion evaluation based on drainage, lineament, lithology, slope and landuse and opined that high groundwater potentiality is in flood plains and river terraces. Sarvari et al (2006) conducted a study to identify suitable sites for artificial recharging by overlaying of the slope, surface infiltration, thickness and quality of sediment layers in GIS.
Based on the literature, a study was carried out in the Noyyal river basin of Tamil Nadu, India to identify the areas suitable for artificial recharging using Geographical Information System (GIS). Noyyal basin is a water stressed basin, as cultivation of crops is the main occupation of the people. The areal extent of the basin is 3548 km2. The following factors were considered for the study: Landuse, Digital Elevation Model (DEM), soil, geology, lineaments, geomorphology, difference in elevation between the river and adjacent locations and distance from the recharge source(river). The landuse maps was derived from LISS-III image of the study area. The image was classified using supervised classification technique using ERDAS Imagine software and the classified image was digitized to obtain landuse map. DEM was derived from the slope map(contour map) of the study area. Soil, geology, lineament density and geomorphology raster maps were obtained from scanned copies of the district maps covering the basin. As the areas at lower elevations are more suitable for recharging a raster map was obtained showing the difference in elevation between the river and adjacent locations. As the water can be easily diverted to the nearby recharge sites another raster map was considered with the distance from the river as criteria. All the above mentioned input raster maps were reclassified by giving priority according to their influence factor for recharging. . After reclassifying all the input rasters, suitability map showing area suitable for groundwater recharging was obtained using weighted overlay approach of ArcGIS 9.2. Appropriate weightage has been assigned to each information layer according to its relative contribution towards the desired output. The factors geomorphology, landuse and lineament density were given higher weightage.
Keywords: Artificial recharge, Groundwater, Overlay analysis
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