Paper Title
Development of Flood Mitigation Measures for Mandalay

Abstract
Urban flooding meansthe substantial challenges to infrastructure, public safety, and urban development. Mandalay, Myanmar’s second-largest city, faces recurring flood events due to inadequate drainage network, rapid urbanization, and climate variability. This paper aims to measure the flood mitigation scenarios from the SWMM simulation results and identifying flood prone areasin the Shwe Kyin Basin, Thin Ga Zar Basin, and Pa Yan Taw Basin of Mandalay. Flood hazard maps for 10,30, and 50year return periods were developed using QGIS based on the simulation results. In the development of the flood hazard maps, the flood depth was classified into four flood risk levels, with the moderate flood risk level being the most frequent across all three basins. Based on these findings, this study proposes flood mitigation measures including both engineering and non-engineering scenarios using SWMM 5.2.Three flood mitigation scenarios were evaluated with modifying the percentage of impervious surfaces in the land area, modifying channel dimensions, and integrating land use changes, channel dimension modifications with the design of retention and detention basins within the SWMM model. According to the evaluation of scenario 1 and 2, the flood risk levels for different return periods did not significantly decrease.The evaluation of scenario 3 indicated the most effective long-term flood mitigation measures. The measuresprovide the essential guidance for urban planning and flood risk management, offering valuable information to reduce flood impacts and support sustainable development in Mandalay. Keywords - Flood hazard maps, Flood mitigation measures, Mandalay, QGIS, Return periods, SWMM 5.2