Deciphering of Groundwater Recharge Potential Zones in Dhaka City, Bangladesh by RS and GIS Techniques

Groundwater resources in Dhaka city have reached critical limits due to over-exploitation. Over-pumping of groundwater accompanied by lack of replenishment via infiltration have resulted in substantial declination of water-levels over the last two decades. Replenishment of groundwater using artificial recharge is therefore essential for proper management of groundwater resources in the city. This study employed various remote sensing (RS) data and geographical information system (GIS) techniques to explore favorable artificial recharge sites for Dhaka city. Different influential thematic layers such as drainage density, lineament density, land use/land cover (LULC), slope, and lithology were integrated by weighted overlay method to form a new integrated layer. The integrated map reveals favorable artificial recharge zones in Dhaka city. The results of the study reveal that about 11% of the study area can be considered to possess excellent potential for artificial recharge, while 25%, 23%, 22%, and 19% of the study area demonstrate good, moderate, low, and poor potential, respectively. The outputs of the study could contribute to effective planning for future projects on artificial recharge in Dhaka city.