基于FLO-2D数值模拟的工布江达县城泥石流灾害危险性评价

Hazard assessment of debris flows in Kongpo Gyamda,Tibet based on FLO-2D numerical simulation

工布江达县位于藏东地区,雨季区内泥石流频发,对人民基本生活和区域经济建设与发展造成了严重影响。为研究藏东地区中—小型泥石流灾害对城镇居民聚集区的危害特征和潜在危险性,运用FLO-2D软件,以西藏自治区工布江达县县城周边居民分布较为集中的5条泥石流沟为研究对象,通过模拟泥石流泥深和流速等方面的冲淤特征,以县城典型泥石流沟模拟冲出结果为基础,确定泥石流强度并划定危险性分区,分析泥石流危险分区与居民聚集区之间的拓扑关系,评估县城周边泥石流危险性,为工布江达县城的城镇规划和防灾减灾提供技术参考。

Kongpo Gyamda is located in eastern Tibet,where debris flows occur frequently in the rainy season,which has a serious impact on local people’s daily life and hinders regional economic construction and development.In order to study the hazard characteristics of small to medium-sized debris flow in eastern Tibet and potential dangers to urban residential areas,the FLO-2D software was used to study five debris flow gullies with relatively concentrated residents around Kongpo Gyamda.The scouring and silting characteristics of debris flows were simulated.Based on the simulation results in terms of depth and velocity,the intensity and hazard zoning of debris flows were determined.By analyzing the topological relationship between the debris flow danger zone and the residential area,the debris flow risk around the county was evaluated.It provides technical reference for the town planning,and disaster prevention and mitigation in Kongpo Gyamda.