山丘区沿河村落山洪灾害受灾水位及危险区划分方法

Disaster level and dangerous zone division in flood disaster along with river villages in hilly areas

随着山丘区小流域山洪灾害防御工作的精准化推进,山丘区河道沿岸局部重点区域(村落、集镇)已经成为山洪灾害重点关注对象。针对沿河村落开展暴雨洪水分析,定位村落内防洪能力最薄弱的居民户,计算受灾水位,分析不同频率洪水水面线下的淹没人口,绘制山洪灾害危险区是山洪灾害防御、预警工作的核心和难点之一。针对目前受灾水位和危险区划分存在的问题,根据现场调查和测量资料,综合设计暴雨洪水计算、水位-流量关系计算、点投影、点线关系判断等方法,提出了一种可行的受灾水位计算、受灾人口判定和危险区绘制方法。采用Matlab编程批量计算,以济南市小李庄村为例进行了应用实践。结果表明,该方法可准确定位防洪能力最薄弱的居民户,计算沿河村落受灾水位,判定居民户与不同频率洪水水面线的关系,从而较为精确地绘制山洪灾害危险区。

With the advancement of the prevention of flashflood disasters in the small watershed of the mountainous area,the local key areas(villages and towns)along the river in hilly areas have become the focus of flash flood disasters.It is critical and difficult to analyze and to calculate the risk of each village along the river,to determine the unified disaster water level,and to analyze the submersed number of people under different frequencies of floodwater line and the danger zone.This paper introduced the analytical process of the flood control capacity of the village along the river to calculate the water level-river discharge relationship in the control section.Moreover,this study also put forward a feasible method of calculating the disaster water level and counting the number of people in the danger zone by point out the projection and judging point-line relationship.For this purpose,a typical village along the river was taken out to calculate the floodwater line and danger zone.The results showed that the applied method could ascertain the household that was the weakest in the aspect of flood control capacity by combining field investigation and the determined relationship between households and different frequencies of the floodwater line.Therefore,the flood control capacity of the village along the river could calculate accurately.