Flood Risk & Vulnerability Assessment of Lower Indus Basin

Pakistan has been confronting the challenges of many natural calamities, including droughts, earthquakes, floods, and landslides, etc. The floods of 2010 and 2011 caused a huge loss to life, property and land use. These floods disrupted power supply, telecommunication, and water utilities network in many districts of Pakistan, including 22 districts of Sindh (Memon, 2012). The objective of the study is to use the tools of Geographic Information System &Remote Sensing to assess flood vulnerability, map flood prone areas, and identify and disseminate disaster mitigation activities in order to reduce loss of life and property. These floods call for risk assessment and hazard mapping of Lower Indus Basin flowing in the Sindh Province as such areas were also inundated in 2010 flood, which were not flooded in the past in this manner. This primary focus of this paper is the use of HEC-RAS model in integration with the Geographical Information System (GIS) (Papaioannou et. al. 2015) to develop floodplain maps for the part of Indus River that lies in Sindh Province. This research demonstrated how GIS tools can be used to produce map of flood vulnerable areas. The Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) was chosen in the study for the extraction of geometrical data for Indus River. Flood frequency analysis was undertaken using log-Pearson type III (LP3) and Gumbel’s distributions for calculating extreme flows with different return periods. Then the HEC-RAS model, the peak floods values from frequency analysis were entered so as to find the corresponding flood levels expected along river Indus. Finally, a flood hazard Map of Lower Indus Basin was generated which delineates the flood prone areas in the Sindh province along Indus River Basin that could be inundated by potential flooding in future. The data was validated by comparing it with the 2010 flood extent extracted from MODIS. It is aimed that flood hazard mapping and risk assessment using HEC-RAS & geographic information system can serve as a handy tool for the development of land-use strategies so as to decrease the impact from flooding.

کلیدواژه ها:

Geographic Information System ، Flood risk assessment ، hazard mapping ، Remote Sensing ، Disaster Management