Water Availability and Hydrogeological Condition in the Siwalik Foothill of Eastern Nepal

Abstract

The Siwalik foothill is bounded between the Siwalik Range in the north and IndoGangetic Plain in the south. The Siwalik Range is composed of sedimentary rock, mainly the alternating beds of sandstone and mudstone and conglomerate. The Indo-Gangetic Plain consists of coarse sand, gravel, pebble, cobble and boulders in the northern part (Bhabar zone) that becomes finer (up to gravel size) southwards. Because of porous geology, the Bhabar zone is the potential area for groundwater recharge, but there is a restricted water availability due to deeper water table. A detailed investigation of has been carried out in parts of Chulachuli Village Development Committee of Ilam district, Nepal to assess the hydrogeological condition. The secondary information and primary data collected in the field and interpretation of satellite imageries had been carried out to extract relevant information and update the geological map of the area. The Bhabar zone is characterized by the low availability of water for drinking and irrigation purposes while the Middle Terai is represented by better groundwater potentiality.