Flood risk assessment: role of mitigation capacity in spatial flood risk mapping
Naser Ahmed, Muhammad Al-Amin Hoque, Newton Howlader, Biswajeet Pradhan
Abstract
Globally, the frequency, intensity, and damage rate of floods have increased extensively in the last few decades. The present study proposes a spatial-based multi-criteria approach integrating mitigation capacity to map the degree of flood risk. Flood risk is calculated considering 14 relevant factors under three risk components. Thematic layers were ranked through fuzzy membership functions, and risk components were prepared using fuzzy overlay operation. To make a comparison, first, we calculated risk with mitigation capacity and later without it. Results exhibit, without mitigation capacity around 67% of the study area is exposed to high flood risk, while after integrating mitigation capacity flood risks decreased to 62%. Moreover, validation evaluation suggests risk map integrating mitigation capacity is more accurate (82%) than the risk map without it (79%). Therefore, the developed integrated risk mapping approach is more efficient to assess flood risk, and can be implemented by policymakers in similar environments.