Integration of a flood simulation model with GIS and remote sensing for hazard mapping in the lower Mekong subcatchment in Cambodia | |
| Author | Bormudoi, Arnob |
| Call Number | AIT Thesis no.RS-07-1 |
| Subject(s) | Floods--Simulation methods--Remote sensing--Cambodia Floods--Simulation methods--Geographic information systems--Cambodia |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Remote Sensing and Geographic Information Systems |
| Publisher | Asian Institute of Technology |
| Abstract | Flood occurs in the lower Mekong basin in Cambodia almost every year as a result of the seasonal rain. This flood causes loss of life, destruction of public and private properties and disrupts the normal cultivating cycle. This hampers the economic development of the country since Cambodia depends heavily on agriculture for its economic growth. The study is undertaken to recreate the major flood event in the year 2000 in the lower Mekong basin in Cambodia for the four provinces of Kompong Cham, Prey Veng, Kanda! and Phnom Penh. The main objective of the study was the simulation of the ID flood model HEC-RAS for the Mekong river and estimate the flood depth and extent for the year 2000 flood event in the four provinces of Cambodia. The sub objectives were to validate the model by comparing the flood inundation area and depth with the available flood maps and remote sensing image and prepare hazard maps using the model outputs and other socio-economic data. Damage analysis was carried out for a pa1ticular commune using model results and field survey data. HEC-GeoRAS was used as an interface between Arc-View and HEC-RAS. The final map was visualized in Arc View and used for hazard analysis. The methodology adopted comprised of three phases as 1) preparation phase, 2) execution phase and 3) validation and hazard analysis phase. Preparation phase included generation of DEM of the floodplain and the riverbed followed by centerline extraction of the river and creating cross-sections in the river. Geometric corrections of the floodplain and the river cross-sections in HEC-RAS was a part of the preparation phase. Coupling with the hydrological data after defining the boundary conditions was the execution phase. The validation phase comprised of the comparison of the model outputs with the extent and depth of flood base map and field data. Hazard analysis comprised of the using the model output for hazard zonation in a GIS environment from a potential threat of a similar flood event like that of year 2000 using the socio-economic and ancillary data. From the result, it was observed that most of the areas of the four provinces were inundated by the year 2000 flood, which was verified by a base map prepared from SAR data acquired during the flood time. Phnom Penh city was not flooded due to dykes and the highway No.5. The scenarios were simulated in the model results. The flood depth for the year 2000 was achieved by deducting the water level of the driest season from the water level during the flood season using HEC RAS model simulation for March and September respectively. Results show that the flood depth varies from 0 to 9.5 meter in the flood plain. This is in conformity with the data gathered during the field visit. It was observed that most of the area was under medium hazard zone. Area-wise Kandal province has the highest hazardous area. It was found that a length of 2286 Km of roads and a total of 449 numbers of schools were affected by the flood. From the damage analysis, it was found that damage to the buildings varied from 0.06 to 40 percent in the Chrouy Changva commune. From the regression analysis it was observed that depth and duration had the highest correlation with the percent damage of the buildings. Finally, percent damage per pixel considering the depth of floodwater showed a damage of 0.7 to 11 percent in the study area. |
| Year | 2007 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Remote Sensing (RS) |
| Chairperson(s) | Hazarika, Manzul Kumar |
| Examination Committee(s) | Chen, Xiaoyong;Arambepola, N.M.S.I.; |
| Scholarship Donor(s) | State Bank of lndia;AIT fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |