白龙江流域甘家沟泥石流风险评估研究

Risk assessment of debris flow in the Ganjia Gully of the Bailongjiang Basin

针对不同降雨条件下泥石流的危害特征及潜在风险,以白龙江流域甘家沟为例,探索了单沟泥石流风险评估方法,包括泥石流危险区划、易损性分析和风险评价三方面主要内容。采用FLO-2D模型模拟不同降雨条件下的泥石流危险度;通过遥感解译和承灾体价值核算分析,并结合不同降雨条件下的承灾体受损概率,得到承灾体易损度。将危险度和易损度归一化处理,最终得到研究区风险区划,同时对各类承灾体财产损失进行评估,结果表明:20年、50年和100年一遇的损失价值分别为31849.21万元、34886.50万元和39125.87万元。从20年到100年一遇条件下,高风险和极高风险区的面积大幅度增加,其中极高风险区的面积分别增加2.44倍和3.92倍。

A systematic method for risk assessment of single-channel debris flow is studied in the Ganjia Gully of the Bailongjiang Basin. The method includes three main contents: risk zoning of debris flow hazards,vulnerability analysis and risk assessment. Debris flow hazard is simulated by FLO-2 D fluid model under different rainfall conditions. Vulnerability is obtained by high-precision remote sensing interpretation and statistical analysis of the value of disaster-bearing bodies and considering the damage probability of disaster-bearing bodies under different rainfall conditions. Through the coupling of risk degree and vulnerability degree normalization treatment,the risk zoning of the study area is finally obtained,and the property losses of various disaster-bearing bodies are evaluated. The results show that the value losses of once-in 20 a,50 a and 100 a are 318. 4921,348. 865 and 391. 2587 million yuan,respectively. In the case of once in 20-100 years,the high-risk area of the extremely high risk area increased by 2. 44 and 3. 92 times respectively.