Flood Risk Map using Remote Sensing and GIS: A Case Study of Champhone District of Savannakhet Province, Lao PDR
The objectives of this project were: 1) To prepare flood hazard and vulnerability maps, 2) To identify flood risk area.
The study area of this project was Savannakhet province in Lao PDR. A landuse map was prepared for the study area using ASTER data of dry season of 2005 and settlement/urban boundaries extracted from ALOS/PRISM data of September, 2006.
A potential flood map was prepared by using ASTER/AVNIR data of October 2004 and September 2006. Both of these images were acquired during the flood season. Classification of remote sensing data was carried out using visual interpretation. Road and building location were extracted from ALOS/PRISM data and these maps were later overlaid on the flood map to identify the elements at risk and assess their vulnerability. Adopting the same concept, landuse map was also overlaid on the flood map to assess the vulnerability of various landuse. Statistics of the affected area by landuse as well as number of buildings and villages were estimated. The total of flood affected area was 188 km2 and 49 km2 of this was categorized as high hazard zone. There were 15 villages in this high hazard zone and 56 buildings were affected. Fifty three percent of the flood affected area is agricultural land.