Application of fuzzy analytic hierarchy process and geospatial technology to identify groundwater potential zones in north-west region of Bangladesh

Abstract

Over the last couple of decades, excessive use of groundwater has caused the depletion of groundwater resources in many parts of the globe. The northwest region of Bangladesh, which experiences frequent dry spells and low rainfall, is in severe water-stressed condition. Without sustainable planning and management, this region might experience a severe water crisis. Therefore, this research aims at delineating potential groundwater zones in the Rangpur Division of northwest Bangladesh by analyzing ten topographical and hydrological features derived from the literature review. Related data and information are extracted from the Landsat 8 image, digital elevation model (DEM) data of USGS and other secondary sources. This study has employed the Fuzzy Analytic hierarchy process in the GIS platform to generate the result. The findings suggest that about 3647 km2 (22.3%) of the study area has very high groundwater potential. On the contrary, 4320 km2 (26.5%) areas have low groundwater potential. The highest groundwater potential sub-region is located on the eastern part of the study area along the Brahmaputra River. The lowest groundwater potential sub-region is located on the western part of the study area which is part of the old Barind tract. The results are validated with the receiver operating characteristics (ROC) curve statistics. The AUC value of 0.84 implies that the model has successfully identified the groundwater potential zone in 84% of cases. Validation of the findings was also performed by analyzing the correlation between groundwater potential index and the depth of water level from 80 different wells (R2 = 0.68). The findings would help policymakers and planners in sustainable planning and management of groundwater resources in the northwest region of Bangladesh.