Thailand was hit by a great flood in 2011 resulting from irregular rainfall during the typhoon season that was estimated at 140% more than average. The flood began in the north and slowly moved to the central region, where it remained for more than 4 months. The flood caused great damage to the economy because it adversely affected industrial estates and agricultural areas. In the north, there are four main rivers in the region that combine into a river called Chao Phraya in the central region. The Yom River is one of the northern rivers where no large-scale dam has been constructed, resulting in frequent flood and drought. Sukhothai Province is located in the Yom Basin, where flood and drought occur on a regular basis, and the province was also severely damaged in the 2011 flood. In order to estimate flood damage cost in 2011, a simple regression curve is presented first to relate flood areas and damage cost based on past records. The 2011 flood in Sukhothai province was then simulated by using a Rainfall-Runoff-Inundation (RRI) model with satellite based rainfall (TRMM). After simulation results were compared with the observed stream flow water level, discharge and inundation extent, this study estimates damage cost for the 2011 flood based on the simulated flood area. The proposed approach could be a useful guideline in damage cost computation.

1. [1] T. Sayama et al., “Rainfall-runoff-inundation analysis for flood risk assessment at the regional scale,” Proc. of the Fifth Conf. of Asia Pacifc Association of Hydrology and Water Resources (APHW), pp. 568-576, 2010.
2. [2] T. Sayama, G. Ozawa, T. Kawakami, S. Nabesaka, and K. Fukami, “Rainfall-runoff-inundation analysis of the 2010 Pakistan flood in the Kabul River basin,” Hydrological Science J., Vol.57, No.2, pp. 298-312, 2012.
3. [3] Royal Irrigation Department, “Study Report of YOM and NAN River Basin for Flood Mitigation,” Main Report, 2004.
4. [4] S. Koontanakulvong, A. Sriariyawat, and K. Pakoksung, “Sukhothai flood risk management under changing climate,” Proc. of 2012 AIT-NUS-ITB-KU Joint Symp. on Human Security Engineering, Bangkok, Thailand, 19-20 Nov. 2012, 2012.
5. [5] The CGIAR consortium for Spatial Information, “Shuttle Radar Topographic Mission (SRTM),” 2008,
   Available: http://srtm.csi.cgiar.org/ [accessed August 19, 2008]
6. [6] United State Geological Survey, “Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales (HydroSHEDS),” 2008,
   Available : http://hydrosheds.cr.usgs.gov/index.php [accessed January 31, 2008]