淹没分析在山洪泥石流风险评估中的应用初探——以河南省灵宝市大湖峪山洪泥石流沟为例

Application of Submerged Analysis in Risk Assessment of Mountain Torrents (Debris Flows)

山洪泥石流是一种突发性的地质灾害,历时短暂,破坏性大。本文通过对河南省灵宝市大湖峪山洪泥石流沟进行淹没分析,在水文模拟基础上,用HEC-RAS、HEC-GeoRAS耦合ArcGIS模型对山洪泥石流进行分析,实现了山洪泥石流淹没范围的三维显示,获得泥石流淹没水深及淹没面积。进而对大湖峪主峪道及其支沟进行风险评估,所得的泥石流风险评估结果为泥石流的防治和预警提供了科学依据。研究中发现该流域遭遇30年、60年和120年一遇山洪泥石流时,大湖峪五个居民点均会被淹没。因此可以初步判断大湖峪矿区泥石流灾害的隐患相当严重,属于具有高风险的泥石流沟。其发生泥石流的物源条件、地形条件都已具备,一旦水源情况达到,泥石流就会危及到流域下游居民区的生命及财产安全。这一风险评估结果与大湖峪历史发生的泥石流灾害和灾情的实际情况基本相符。本研究实现了三维淹没分析与灾害风险评估的结合,为山洪泥石流的预测预报和风险评估研究提供了新思路,也为其他类似泥石流区域进行该方面的研究有一定参考价值。

The mountain torrent(debris flow)is a sudden geological disaster,which lasted for a short time.Once the debris flow occurs,the consequences will be disastrous.This research,through the sub-merged analysis of the debris flow in the Dahu valley,Lingbao City,Henan Province,based on the hydrological simulation and the model of the HEC-RAS,HEC-GeoRAS coupled GIS,we have obtained the three-dimensional display of the submerged range of the torrential(debris flow)and the submerged depth and submerged area of the debris flow.And then carries on the risk assessment to the main lake road and its ditch,the debris flow risk assessment result provides the scientific basis for or the early warning,prevention and control of debris flows in the Dahu valley.The study found that in the 30-year flood conditions,60-year flood conditions and 120-year flood conditions,the five settlements in Dahu valley will be submerged.We can make a preliminary judgment that the hidden trouble of debris flow is very serious in Dahu valley.It belongs to the debris flow ditch with high risk.The debris flow has both source and topographic conditions,once the water resources are reached,the debris flow will endanger the life and property safety of the lower reaches of the valley.The risk assessment result is basically consistent with the actual situation of the debris flow disaster and the disaster situation occurring in Dahu valley.This study realizes the combination of three-dimensional submerged analysis and disaster risk assessment,this achievement provided a new idea for the prediction and forecasting of mountain torrents(debris flow).It also has a certain reference value for other similar debris flow in the aspect of this study.