이상홍수에 따른 남한강 유역의 홍수저감대책 분석

Abstract

The rainfall characteristics is changing in Korea due to a climate change and global warming occurring all over the world. Because mean annual precipitation is increasing while the total precipitation days are decreasing, ultimately the rainfall intensity is increasing. Considerable losses are expected because of abnormal floods. Accordingly, it is necessary to establish the reasonable countermeasures to cope with disaster due to a climate change by suggesting diverse alternatives. The goals of this study are to assess the vulnerability for abnormal floods, to analyze the disaster decrease capability by applying the diverse disaster prevention alternatives, and to derive the suitable alternative. The South Han River Basin selected as a test basin controls floods only with Chungju multi-purpose reservoir and levee. Since the flood control capacity of Chungju reservoir seems not to be sufficient compared to its large catchment area, the operation of Chungju reservoir may affect the state of flood damages in the upstream and downstream of the reservoir. The flood discharge close to the design flood occurred at Yeoju bridge, which is the one of the main control points in the test basin, from July of 2006 storm. That shows the weakness for flood protection in the test basin. Accordingly, the flood event of 2006 is analyzed and the storm events equivalent to 1 ~ 1.5 times are simulated for the basin vulnerability. Finally, the flood decrease alternatives are established based on the analyzed flood vulnerability and the capability of flood management is assessed for each alternative in case of PMF occurrence in Chungju reservoir basin. The results show that the development of a new reservoir, one of the structural methods is the most efficient alternative if the suitable reservoirs system operation is accomplished.