Deciphering of groundwater potential zones in Tuticorin, Tamil Nadu, using remote sensing and GIS techniques

Abstract

The present study was carried out to decipher the groundwater potential zones in the coastal terrain of Tuticorin using Indian remote sensing satellite IRS-1C, LlSS-III data on a 1:50,000 scale and Survey of India (SOI) toposheets. The thematic layers such as lithology, slope, land-use, lineament, drainage, soil and rainfall were generated and integrated to prepare the groundwater prospect and recharge map of the study area. These layers were transformed to raster data using feature to raster converter tool in Arc GIS 9.2 software. Subjective weights are assigned to the respective thematic layers and overlaid in GIS platform for the identification of potential groundwater zones within the area. These potential zones were categorized as ‘high’, ‘moderate’, and ‘low’ zones with respect to the assigned weightage of different thematic layers. The resultant map shows that 10% of the area has highest recharge potentials, this is due to the percolation of precipitated water into the sub-surface rocks, followed by 65% of the area with moderate groundwater recharge potentiality, and rest of the area has low recharge potential. The study highlights that the total average annual precipitated water (877 mm) is responsible for natural recharge of the aquifers in the Tuticorin area.