Groundwater potentiality study in drought prone barind tract, NW Bangladesh using remote sensing and GIS

Present study is carried out in the drought prone Barind tract in the north-western part of Bangladesh to identify zones of groundwater potentiality using remote sensing (RS) and geographic information system (GIS) based geospatial multi-criteria approach. Decreasing rainfall trend along with increasing demand for groundwater irrigation of this agro-based area utters urgent need for sustainable groundwater resource development. The study area possesses sub-dendritic drainage pattern with highly irregular to irregular geomorphological character with mostly flat to gentle slope represents 'not so good category' for groundwater development because of lower rainfall with less favorable infiltration capacity of top soil with respect to time of percolation of runoff. Here major portion of runoff water loses and not allows more infiltration to recharge the groundwater and, therefore is less potential for groundwater occurrence and development. To delineate groundwater potentiality, thematic layers like geomorphology, drainage density, rainfall, lithology, lineament density, slope and land use/land cover (LULC) have taken into consideration to integrate in the GIS environment, and has categorized as: 4% (48 km(2)) - very good, 13% (170 km(2)) - good; 25% (342 km(2)) - moderate; 30% (405 km(2)) - poor; and 28% (365 km(2)) as very poor category. On the other hand, this potential zonation is most sensitive to lithology; followed by slope and lineament density; and succeeded by geomorphology, drainage density, rainfall, and LULC. This study helps not only to classify zones of groundwater resource potentiality, but also to assess groundwater resource potentiality and scopes for its future development at a glance and provides a guideline for the groundwater resource management approach particularly in the area.