山美水库洪水淹没分析及方法研究

在全球极端天气逐年增多的背景下，自然灾害发生的频次和强度愈来愈大。中国为防洪抗旱近年来兴建水库，而水库一旦发生洪水灾情，水库的泄洪淹没范围对下游防汛规划及减少灾害损失至关重要。以山美水库为例，基于地理信息系统(geographic information system, GIS)技术选用有源淹没方法确定山美水库遭遇3种重现期洪水泄洪的淹没范围，并利用洪水量等于淹没水量的原理，提出了一种运用二分法迭代有源淹没的淹没水位确定方法。通过输入3种不同重现期洪水量，本研究模拟出山美水库遭遇20年一遇洪水时下游淹没面积为20.04 km²,遭遇50年一遇洪水时下游淹没面积为24.42 km²,遭遇100年一遇洪水时下游淹没面积为26.07 km²。结果显示，淹没区域集中在水库下游的梅山镇、罗东镇、码头镇。研究结果可为地方政府管理洪水风险、制定防洪措施提供一定的参考。

Analysis and Method of flood inundation in Shanmei Reservoir

With the global extreme weather increasing year by year, the frequency and intensity of natural disasters are increasing. In recent years, China has built lots of reservoirs for flood control and drought resistance. Once a flood occurs in a reservoir, the flood discharge and inundation range of the reservoir is very important for downstream flood control planning and disaster loss reduction. This study took Shanmei Reservoir as an example. the active inundation method based on GIS(geographic information system) technology was selected to determine the submerging range of the three flood discharge periods of Shanmei Reservoir. Through using the principle that the flood volume is equal to the submerged water volume, a method to determine the submergence level using dichotomy iterative active submergence is proposed. By inputting three flood quantities in different recurrence periods, this study simulated that the downstream inundated area of Shanmei Reservoir was 20.04 km2 when it was hit by a 20-year flood, 24.42 km2 when it was hit by a 50-year flood, and 26.07 km2 when it was hit by a 100-year flood. The submergence range and submergence depth under the corresponding flood volume showed that the submergence area is concentrated in Meishan Town, Luodong Town and Matou Town downstream of the reservoir. The results of this study can provide some references for local governments to manage flood risk and formulate flood control measures.