兰州市安宁区大青沟泥石流灾害危害性评价及治理方案

Hazard evaluation and control scheme of Daqinggou debris flow disasters in Anning District of Lanzhou

大青沟位于安宁区北部,沟口为安宁区城区。大青沟泥石流形成以冲蚀汇流和主沟冲蚀为主,流域中、上游受平山造地、回填沟谷的影响,固体物质较丰富。泥石流堆积分为沟道堆积和沟口堆积,泥石流危害区主要是沟口堆积区,危害方式以冲毁、淤埋及冲刷为主,泥石流灾害损失在逐年增大。严重危害区占整个危险区的43%,一般危害区占整个危险区的57%。泥石流治理主要采用拦挡工程和排导工程两种治理方案,研究可为防灾减灾提供可靠的依据。

Daqinggou ditch is located in the northern Anning District, whose entrance is the urban area of Anning District. The Daqinggou debris flow is formed mainly by erosion convergence and gully erosion. The middle and lower reaches of this basin with abundant solid matters are effected by the land reclamation in Pingshan area and backfill of the gully. The accumulation of debris flow can be divided into two kinds, including both in the gully and at its entrance. The main debris flow hazard area is the ditch mouth, and the hazards are always destruction, siltation and scouring. The loss due to debris flow hazards is increasing year by year. Severely hazardous areas account for 43% of the entire hazard area, and general hazardous areas account for 57%. Debris flow control mainly adopts two schemes: blocking project and drainage project. This research can provide a reliable reference for disaster prevention and reduction.