水砂分离在武都北山泥石流灾害治理中的应用

The application of water-sand separation in Wudu Beishan debris flow control

武都北山流域构造运动活跃,固体物源丰富,地形起伏,沟道比降大,极端降雨气候频现,为泥石流的形成提供充足条件。2007年,通过采取拦排结合的方案对武都北山泥石流进行治理,治理效果显著。但随着时间推移,拦挡坝自上游向下游不断淤满,泥石流不断向沟口推进;建筑物遍布泥石流沟口,房屋基础挤压、占用排导渠和排洪管网,致使其过流能力严重不足。泥石流活动趋势逐年增强,易损性增大,险情扩大,需再次治理北山流域泥石流。考虑到治理工程的重点在于排水和避让房屋建筑,提出水砂分离的截排水方法治理北山泥石流,从北山流域的内部着手,解决泥石流灾害的威胁。

The active tectonic movement,rich solids source,topographic relief,large channel gradient,frequent extreme rainfall climate of Wudu Beishan valley make adequate preparation for the formation of debris flow. In 2007,Wudu Beishan debris flow have been treated by a scheme combining row and blocking with significant effect. Over time,the dam continue to fill up from upstream to downstream,mudslides continue to promote to stream exit; Buildings spread around stream exit.Building foundation squeeze and occupy flood canal and flood drainage network resulting in its flow capacity insufficient. Debris flow activity trend increases year by year. Due to the vulnerability increase and danger expand,Beishan debris flow need to be governed again. Considering the treatment project focuses on drainage and avoid housing construction,separating water and sand is proposed to address the threat of debris flow in Beishan valley.