Evaluation of nature-based solutions for flood inundation reduction using 1d-2d hydrologic-hydrodynamic model in the Lower Songkhram River Basin, Thailand | |
| Author | Katuwal, Ashwin |
| Call Number | AIT Thesis no.WM-23-19 |
| Subject(s) | Flood control--Thailand--Songkhram River Basin Hydrologic models--Thailand--Songkhram River Basin |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | A flood is a random event and it cause severe impacts like life threating, economic damages, transportation disturbances, etc. The Lower Songkhram river basin had faced many severe floods due to backflow from Mekong River and heavy rainfall upstream. Sub-basin scale sensitivity analysis plays an important role in selecting spatially varying nature-based solutions. Furthermore, inter-process sensitivity analysis also plays an important role while deciding where to apply NBS, either in sub-basins or river channel. First, integrated 1-D hydrologic and hydrodynamic model was set up and then calibration was also done in integrated manner by using the observed flow hydrograph and timeseries water level for time 2013 – 2015 and then validated by flood event 2016. Calibration and validation of hydrologic model was done at two different stations but for hydrodynamic model only 1 station in between upstream and downstream boundary condition was selected. The integrated 1-D model was integrated with 2-D hydrodynamic model by assigning calibrated roughness parameter by area weightage method and 2-D model was validated using observed Landsat 8 data. Then, sensitivity analysis for each sub-basin was performed on a control point using a 1-D model with respect to water level. Also, sensitivity analysis was done for integrated flood model. For calibration and validation of 1-D model, the ISE varied from 0.686 to 2.58, NSE varies from 0.828 to 0.925 and Pearson correlation coefficient varies from 0.926 to 0.928. For 2D model validation % overlay was 61.04%. From the sub-basin scale sensitivity analysis two NBS infiltration trenches and permeable pavement were selected and implied to each sub-basin according to their sensitivity. From the integrated flood model sensitivity analysis, hydrodynamic parameters showed more sensitive and monkey cheeks were selected to treat river channel. The reduction in flood inundation by treating sub-basin was 7.97%, by treating river channel was 22.07% and by applying both river treatment and sub-basin treatment was 28.48% |
| Year | 2023 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shanmugam, Mohana Sundaram;Ho Huu Loc (Co-Chariperson); |
| Examination Committee(s) | Shrestha, Sangam;Natthachet Tangdamrongsub; |
| Scholarship Donor(s) | Asian Institute of Technology Scholarships; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2023 |