Flood Hazard Mapping in Seiktha and Zalun Area in Ayeyarwady River
The objective of the project was to prepare a flood hazard maps of different return periods in Ayeyarwady River. Data used in the study were satellite data (Landsat ETM+), topographic data (Spot heights from aerial photographs), river discharge and water level and ancillary Data such as district boundary, population date etc.
A Triangulated Irregular Network (TIN) was created from spot heights of the study area which were generated from the aerial photographs. Measured river cross sections were available only at the upstream (Seiktha) and downstream of the river (Zalun). Steady sub critical flow was carried out using the HEC-RAS model for flood modelling. Results showed that Hinthada and Tharyarwaddy were the worst affected districts by a 100-year flood and in particularly affecting the Hinthada, Kayngin, Ngaputaw, Myangaung and Mingalardon towns with flood depth up to 5m. The total area inundated by a 100 year flood was 2,303 km2.
The flood hazard maps had helped the Department of Meteorology and Hydrology of Myanmar assessing the flood risk in the Ayeyarwady basin and planning for taking necessary risk mitigation measures.