博士 / 國立成功大學 / 水利及海洋工程學系碩博士班 / 101 / Regarding the effects of rivers and seas to river drainage, the flood modeling usually assumes that the water of the rivers and seas does not invade to the internal water, or calculate the river/sea effect separately. However, the assumption is against the truth, and therefore cannot reflect the hydrodynamic phenomena of the coastal low-lying areas when experiencing drainage difficulty resulted from water surging at the sea estuary during the typhoons or storms. Consequently, it is necessary to simulate the river hydrodynamic with storm surge level derived from external and internal water coupling.
In recently years, the severe Climate Change has caused extreme rainfall and frequent floods that seriously threaten coastal low-lying areas. It is not enough for old riverbank safety protection and river management to only focusing on embankment structure or river management itself. It is necessary to consider the interaction of river adjustment and external water from the seas through river estuary. In other words, the concept of “co-management of rivers and seas” needs to be applied. This study adopted numerical simulation based on “river and sea hydrology coupling model”, which was capable to simulate the hydrodynamic of the whole area of the rivers and seas under high intensity, long-lasting, and large range rainfall. The broken overflow conditions in Linbian Village of Kaohsiung in Taiwan during the typhoon disaster on 8th Aug. 2009 were taken as the simulation object. The wind field data of Linbian Creek estuary was integrated with typhoon wave model (WWMⅡ) and surge model (POM) for the simulation analysis and calculation of the maximum surge level of the river estuary. The results were used as the downstream boundary conditions when implementing simulation of broken overflow and flooding of Linbian Creek through waterway WASH123D model.
The results of WASH123D model simulating the burst embankment of Linbina Creek indicated the damage mechanism as follows：
1. The surge at estuary indeed prevented the river water from flowing into the sea. In consequence, the water level of the river was raised and caused backwater. When the surge ebbed away, the hydrodynamic impact caused by the descending water level resulted in seepage within the embankment (core) and toe scour. Therefore, the slope structure collapsed to cause the groundwork sliding and gradually led to Linbian Creek embankment breaking in the north of the Railway Bridge and burst embankment at Jiadong.
2. The Jhuzihjiou Embankment burst resulted from the burst of Sinpi Drainage earthbank. The overflowing water kept scouring the bank foot on the side of the land, where was also the concave bank of Linbian Creek. Besides, the rainfall lasted for a very long time and caused great amount of flood water. The invading of the water flow, circulation at the river curves, and the scoured land-side embankment groundwork steepened the bank, unsettled the upper structure, and finally collapsed the Juzihjiou Embankment.
| Identifer | oai:union.ndltd.org:TW/101NCKU5083121 |
| Date | January 2013 |
| Creators | Wen-JungChen, 陳文忠 |
| Contributors | Tai-Wen Hsu, 許泰文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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