Flash flood water management practices in Dera Ghazi Khan City (Pakistan): a remote sensing and GIS prospective

Abstract

Flash flood hazard of Wador hill torrent has distressed human activities in almost every part of Dera Ghazi Khan (D.G. Khan) City, Pakistan. In order to mitigate such hazards, and to utilize the flash flood water in such water-deficit area, the study identifies potential suitable sites for dam construction with quantitative assessment resulting in capacity determination of the designed dams. The developed methodology also incorporates the designing of downslope water conveyance system in storm water management model’s (SWMM) environment. The efficacy of the dams was analyzed using SWMM model’s runoff and transport module by integrating meteorological and topographic factors with the utilization of curve number method for runoff generation and modeling. Two sites were identified as suitable for dam construction with sufficient collective designed capacity of approximately 27 million m3 to store the flashy peaks. Number of channels designed results in systematic waterways to flow from the dam site to the outlet point (D.G. Khan Canal). The findings may be useful for mitigation strategies of the severe weather conditions. Similar integrated approach could be used for mitigation of flash flood around the world.