Delineation of groundwater potential zones of Atrai–Sib river basin in north-west Bangladesh using remote sensing and GIS techniques

Present research work is carried out in the Atrai–Sib river basin in the drought-prone but agro-based Barind area in the north-west of Bangladesh to delineate the groundwater potential zones using integrated approach of remote sensing (RS) and geographic information system (GIS)-based multi-criteria evaluation. Decreasing trend in rainfall along with increasing population in this drought-prone area calls for a sustainable development of the groundwater resource. The river basin possesses dendritic drainage pattern and major portion of runoff water allows more infiltration to recharge the groundwater and is, therefore, a potential for groundwater occurrence. The gentle to flat river basin is of ‘excellent’ category for groundwater management because of favorable infiltration to maximum time of runoff percolation. Here, seven different thematic layers such as, geomorphology, drainage density, rainfall, lithology, lineament density, slope and land use/ land cover (LULC) are integrated in GIS environment to study groundwater potentiality. Corresponding normalized rates for the classes in a layer and weights for the thematic layers are computed using Saaty’s Analytical Hierarchy Process (AHP), and then aggregated thematic map is prepared using a weighted linear combination (WLC) method. Map-removal and single-parameter sensitivity analysis are used to examine the effects of removing any thematic layer on the groundwater potential zones and to compute effective weight, respectively. About 226 km² (6% of the study area) is designated as very good groundwater potential zone, whereas that of good, moderate, very poor and poor groundwater potential zones cover 407 km² (11%), 720 km² (19%), 997 km² (26%) and 1418 km² (38%), respectively. Sensitivity analysis shows that the groundwater potential zonation in the study area is most sensitive to lineament density (mean variation index 2.66), which is the most effective thematic layer in the groundwater potentiality zone (mean effective weight of 27.13%) and supports the need for future river basin development and management. This study can help to identify the groundwater potential zones of this drought-prone area that will lead towards the planning of the integrated water resources management.