德宏“7.5”特大滑坡泥石流灾害分析及其对策

受滇缅高压外围强对流天气影响,2004年7月5日云南德宏州的陇川、盈江、瑞丽等县(市)普降暴雨,引发大面积的滑坡、泥石流和山洪灾害,造成死亡18人、失踪24人、直接经济损失4.8亿元的区内近几十年来最严重的灾害。在分析此特大滑坡、泥石流、山洪灾害的活动特点、形成条件和激发因素的基础上,得出今后一段时间该区地质灾害将处于活跃期的评估结论。针对这一状况,提出了应急措施和防灾减灾对策。

Analysis and Counter-Measure for the Large-Scale Landslide-Debris Flow Hazard in Dehong, Yunnan, China

On July 5,2004,a large-scale landslide-debris flow disaster took place in Dehong,Yunnan province,China.The disaster is located in the area Southeast of Qinghai-Tibet Plateau,the most severe region of geological hazards in China.More than 90 percent villages and towns are affected by the disaster in Dehong.18 people were killed and 24 people were missing.The total losses amounts to RMB 480 million.The disaster has four features:(1) the occurrence of disaster was catenulate;(2) the occurrence of disaster was in a cluster;(3) There were many trunks and branches of trees mixed with the debris flows;(4) the occurrence of debris flows was in low frequent.By analysing the characteristic of the disaster and disaster area,we can see that abundant loose solid materials,big landform elevation difference and the intensity rainfall process are the main reasons for the disaster.GIS and Landsat ETM+ are used to analyze the cause of disaster.The main cause of the occurrence is the especially heavy rainstorm.But Dehong′s severe weathered earth surface and fragmental terrain are essential conditions.Under those circumstances,disasters will be more and more active in the near future.To cope with this situation,closer investigation and risk assessment for Dehong must be executed.What should be done in next step is put forward.