Author(s): Cheng-Chia Huang; Jihn-Sung Lai; Fong-Zuo Lee; Yih-Chi Tan; Hui-Ming Hsieh
Linked Author(s):
Keywords: Climate change; Bed deformation; Quasi two dimension model
Abstract: Taiwan's rivers flow across the long, narrow island, rising in the Central Range and descending to the coasts, they are all short and steep. Therefore, rivers were damaged by climate change, earthquakes, typhoons, floods, and all kinds of nature disasters, and which Tamsui River suffered the most. For the purpose of decrease sediment trap in upstream reservoir, the sediment has to effluent into downstream river during flood period. The river sediment deposition and erosion would be thus more violent. In order to understand the short and long-term river bed deformation, the quasi two dimension model, NETSTARS, was adopted in this research. The model was calibrated and verified with field survey data during typhoon period, so as to predict the spatial and temporal variations of downstream river bed. The water level and bed elevation movement in typhoon events were investigated via the numerical model at downstream river reaches. The deformation of river was also discussed for Longterm effects due to climate change. According to the result, the impact of one or two typhoon events was slight, the river bed would be deposit or erode in different reach, but the bed of variation was less than one meter. However, Effect of long-term case would be dramatic, and the safety of river embankment would be threatened. In conclusion, the solution about could be offered, to understand where the vulnerable river reach is. Then, measures can be elaborate.
Year: 2016