DELINEATION OF GROUNDWATER RECHARGE-DISCHARGE ZONE, TEESTA-JALDHAKA INTERFLUVE, EASTERN INDIA

Abstract

The Teesta-Jaldhaka Interfluve is, towards the north-east of West Bengal, lying in Jalpaiguri district. The area has a contrasting set-up between the Bhabar and Terai regions. The Teesta River forms the western boundary while the Jaldhaka River forms the eastern boundary of the study area. The Bhabar and Terai regions of Teesta-Jaldhaka Interfluve annually receive about 4000 and 3000 mm of rainfall, respectively. The areal distribution of rainfall has been calculated by creating Thiessen polygons using ArcGIS v.10.8 software. The runoff coefficients for the Bhabar and Terai regions have been determined as 0.8 and 0.84, respectively, to understand the runoff and recharge through rainfall infiltration processes in these two different regions. The water table fluctuation and rainfall infiltration methods, and a few empirical formulas have been used for estimating the groundwater potential in the Bhabar and Terai regions of the study area. In this paper, the annual dynamic groundwater resources potential in the Bhabar and Terai regions has been computed for the evolution of the recharge-discharge phenomenon of groundwater in the Tessta-Jaldhaka interfluve of north-eastern India.