Flooding Simulation using MIKE FLOOD Model A Case Study : Lam Taklong River Basin

Abstract

The Lum Takong river basin is the upper watershed of the Nakhon Ratchasima city. The flooding in the urban area can be occured by the high runoff from the Lumtakong river basin. The purpose of this study is then to simulate the flooding area in the Lumtakong river basin based on the MIKE FLOOD model. The both of the one-dimensional model (MIKE 11) and the two-dimensional model (MIKE 21) were applied in the MIKE FLOOD model. Moreover, the MIKE 11-NAM and MIKE 11-HD included in MIKE 11 are the rainfall-runoff model and the hydrodynamic model, repectively. The MIKE 21-HD is the simulation of the upsteady flows in branched and looped river networks and the quasi two-dimensional flows in floodplains using Digital Elevation Model (DEM). The calibration and validation of runoff was concerned during 2010-2011 while the calibration of flooding area was compared with satellite image from GISTDA in 2010. For MIKE 11-NAM, the R² is from 0.434 to 0.826.The WBL is from 0.20% to 15.30%. On the other hand, for MIKE 11-HD, the R² is from 0.466 to 0.903 and the NSE is from 0.165 to 0.671.For MIKE FLOOD, the overall accuracy is 93.6% based on Confusion Matrix. The model simulation can be presented that flooding occurs during 14-30 October 2010 with the minimum flooding area of 50.38 km2 on 14 October 2010 and the maximum flooding area of 206.75 km2 on 18 October 2010. The highest water depth of flooding and lowest water depth of flooding are consisted of 5.618 and 1.227 m, respectively. Futhermore, the MIKE FLOOD model can be considered for flood management in the future.