Evaluation of Flooding area in Lam Phra Phloeng River Basin using MIKE FLOOD

Abstract

The Lam Phra Phloeng river basin is a big river basin located in Nakhon Ratchasima province. The Lam Phra Phloeng river basin faced a big experience flooding, that are flooding in 2010 and 2020, leading to the significant damage economic for local residents. The objectives of this study are to evaluate the flooding areas in the return period 5, 10, 25 and 100 years using MIKE FLOOD modelling, which includes sub-models such as MIKE NAM for analyzing the runoff volume based on rainfall data, MIKE-HD for simulating the runoff of a changing river over time, and MIKE 21 to simulate the two-dimensional free-surface flow conditions. Using daily data from April 1, 2008 to March 31, 2017 and the whole simulated test results, the MKE NAM model has a WBL between 1.0% - 12.3% and R value between 0.772 - 0.849. The MIKE-HD model has a NSE value between 0.906 – 0.916 and R2 value between 0.918 and 0.927. The results can be concluded that the flooding area in the return period 5, 10, 25 and 100 years. are 25.53, 37.28, 48.42, 55.63, 61.83 square kilometer, respectively, or 1.10% 1.60% 2.08% 2.39% and 2.66% of total area in the Lam Phra Phloeng river basin, respectively. The flooding areas covered the most of Tum sub-district in Pak Thong Chai district. The flooding area in the return period 5, 10, 25 and 100 years are 4.6, 6.35, 7.68, 8.58 and 9.56 square kilometer, respectively.