Land subsidence analysis and inundation prediction based on multi-temporal digital elevation model data

Because large amount of ground water have been excessively withdrawn within the lowlands along the southwestern area in Taiwan, the land subsidence becomes a serious problem that property damages and life losses in the subsidence area will be caused by the poor drainage and serious flooding arise during the periods of typhoon and heavy rainfall. Therefore, how to monitor and analyze the land subsidence effectively will be an important study issue. In this study, many kinds of geospatial information are firstly collected and analyzed for subsidence monitoring. The error adjustment of the multi-temporal Digital Elevation Models (DEMs) data is implemented using the Least Squares Collocation (LSC) method proposed in our previous research works. Then the HEC-RAS and FLO-2D models are used to simulate the flood hazards to test the performance of the LSC adjustment method. The results are also used to analyze the influence of the land subsidence for flood hazards.