Thudchai Sansena. The application of hydraulic model with geographic information system for obtaining data to create flood risk mapping in the upper part of mae klong river . Master's Degree(Technology of Information System Management). Mahidol University. : Mahidol University, 2004.
The application of hydraulic model with geographic information system for obtaining data to create flood risk mapping in the upper part of mae klong river
Abstract:
The main objective of this research is to study the runoff of The Mae Klong
River and develop Geographic Information system (GIS) for supporting a Hydraulic
model to simulate and create flood risk mapping based on the hydrological and
hydraulic approach. The process involved runoff frequency analysis by 6 probability
distributions and statistics to determine a suitable probability for designing runoff
frequency and developing GIS data for generated Digital Terrain Modeling (DTM)
and integration of Hydrologic Engineering Centers River Analysis System (HECRAS)
with DTM to develop a regional model for floodplain determination and a
model for simulation of the flood prevention, warning and forecasting.
It was found that the Manning coefficient to identify water discharge of Mae
Klong River, based on water discharge in 1996, to be used in HEC-RAS model was
0.026. However, the return period could be manipulated using the two parameters
lognormal equation. The result from the simulation model for flooding in 1996 could
appropriately be presented in Geographic Information System and Digital Terrain
Model, which is initiated by using contour lines, river spot height and riverside spot
height data. The accuracy of the model is 60 % based upon the comparison of the
flooding area in 1996, interpreted by Royal Irrigation Department, and the flooding
area created by the model.
Further studies should be done on larger areas such as Mae Klong basin by
separating the basin into subbasins. The network link method to integrate subbasins
should be introduced to have an overall view of the basin. The flow runoff in flood
plain, river channel, man-made structures and GIS database were input factors to
study runoff flow behavior and predict flood area. Future studies to obtain roughness
values, GIS data and database management in order to complete the study in the
future are recommended.