Integrating Remote Sensing and Geographical Information Systems for Urban Flash Flood Susceptibility Mapping in Rawalpindi and Islamabad, Pakistan

Abstract

The most devastating type of flood is urban flash floods, which combine lightning-fast speed with the destructive force of a flood. They occur when there is not enough ground storage for more precipitation.

The main objective of this study is to produce flash flood maps using GIS techniques. Mapping urban flash flood vulnerability is essential to managing and mitigating flood risks. This study maps and evaluates Rawalpindi and Islamabad, vulnerability to urban flash floods using remote sensing (RS), and geographic information systems (GIS). A total of seven 07 factors elevation, slope, LULC, rainfall, drainage density, NDVI, and soil map were examined using high-resolution satellite data and GIS techniques. A total 110 flood points were used to create the flood inventory map and random points were used to ensure proper algorithmic analysis. To create accurate susceptibility maps, the dataset was split into 30% testing and 70% training sets. Flood zones were divided into five (05) categories very low (23%), low (13%), moderate (15%), high (22%), and very high (27%). The results showed that the research area's western, southern, and central parts had high susceptibility, which changed to reduced susceptibility zones. Significant insights for urban planning and disaster management techniques were obtained from the effective identification of high-risk regions through the integration of RS and GIS. This approach highlights the importance of accurate flood event documentation and multi-factorial analysis in enhancing urban flood protection.