DEVELOPMENT CHARACTERISTICS OF DEBRIS FLOWS IN HIMA-LAYAS USING REMOTE SENSING TECHNOLOGY

The Himalayan region locates in the western border area of China. It is the highest and youngest mountain chain in the world. This region situates in the collision zone of two plates. It has complicated geological tectonics, powerful neotectonic movements, serious mountain disasters and extremely active debris flows. These disasters frequently endanger the lifeline engineering and life and possession of the local people. However, fewer exploratory efforts are made due to the high-cold, oxygen deficit and the limit of the technology. This article is based on remote sensing research and field survey data of the large-scale and giant debris flows. It reveals that 16 relative concentrated distribution areas are prensent in this region. The debris flows in the northern slope are more developed than those in the southern slope. On this basis, the development regularity is carefully analyzed. The results show that:(1)The activities of debris flows in the Himalayan region are in the active period.(2)The debris flow gully mouths in the research area are mainly distributed in two elevation sections. One is in the range of 2800~3400m and the another is in the range of 4200~4900m.(3)The gully slope of debris flows in old stage is usually little than 100,while that of debris flow in young stage is relatively larger and is usually larger than 300.Gully slope of debris flows in mature stage is between 100and 300.On the other hand, the ice-snow melting water mudflow and rain mudflow almost have the same gully slope and dynamic conditions. The findings can have significance to prevention and treatment of debris flow disasters and the judgement of debris flow activities in this area.