Flood Risk Assessment for Management in the Floodplain of River Khialy, District Charsadda

Moazzam Mf ,Saddique A, Rahman A

This research work is focused on flood hazard, vulnerability and risk in the floodplain of river Khialy, District Charsadda. The study discusses three different elements of potential flood damages such as hazard, vulnerability and risk. Due to gentle slope the study area is mostly affected by recurrent flood. The present study is based on 2010 flood to develop spatial database and hazard, vulnerability and risk assessment. The developed flood hazard map is divided into three different zones of high, medium and low hazard areas. NDVI (Normalized Difference Vegetation Index) tool was applied on the pre and post images of 2010 flood to find the vegetation change of the study area. Return period for flood was calculated through the analysis of discharge data of Swat River at Munda Headworks. Flood frequency analysis was also done on highest peak discharge data of River Swat at Munda Headworks from 1929 to 2010. The data had been calculated for infrastructure vulnerability through different parameters like building age, building material, building damage and building stories for which the data was collected through field survey. A standard questionnaire was designed for all parameters. The parameters were combined through overlay tool to find the vulnerability map and then applied IDW on the overlaid output. A generalized vulnerability map was developed by dividing the study area into different zones on the basis of observation. After developing vulnerability map it was combined with hazard map and by the combination of these a final risk map was developed. As a result mitigation measures were suggested at a suitable location.