PROGRESS IN GEOGRAPHY ›› 2011, Vol. 30 ›› Issue (3): 343-351.doi: 10.11820/dlkxjz.2011.03.013

• Original Articles • Previous Articles     Next Articles

Occurrence Probability Estimation of Landslides and Debris Flows in Mountainous Areas Surrounding the Miyun Reservoir

SONG Yang1,2,3, CHENGWeiming2, BO Yanchen1, WAN Cong2, SHEN Yuancun2, JIANG Yan4, LIU Haijian5   

  1. 1. School of Geography, Beijing Normal University, Beijing 100875, China;d:\PDF\.pdf
    2. State Key Laboratory of Resources and Environmental Information System; Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    3. Aerial Photogrammetry and Remote Sensing Bureau, Xi'an 710054, China;
    4. China Institute ofWater Resources and Hydropower Research, Beijing 100038, China;
    5. China National Environmental Monitoring Centre, Beijing 100012, China
  • Received:2010-10-01 Revised:2011-01-01 Online:2011-03-25 Published:2011-03-25

Abstract: The occurrence of landslides and debris flows is a type of the natural geological disasters, and is closely related to many factors of hazard-formative environments. These factors include both internal conditional factors such as landform and hydrologic and tectonic conditions, and external conditional factors such as earthquakes and rainfall. To highlight the factors that have dominant role to cause debris flows and landslides, referring to the evaluation methods and factors selection in many investigations, this paper presents the regional analyses and evaluations on the factors which have determinative effects on the occurrence of landslides and debris flows based on regional spatial data. A weighting method is built based on experts' experience for all indicators to estimate the occurrence probability of landslides and debris flows. These indicators include landform factors (slope, aspect and slope-shape, relative height difference, and geomorphologic types), environmental factors (vegetation index, channel density and flood submerged area), and geological structural factors (fault distance and density and geological lithology). Based on the sensitivity analysis of these factors, the risk degrees of geological disasters can be obtained by means of multi-factor superposition, which represent the possibility of geological disaster on the statistical meaning (probability). The study is helpful to regional geological disaster prevention. In comparison with the location of the field-surveyed disaster sites with the forecasted disaster zones, it can be concluded that there is a good accordance between the distribution areas of landslide and debris flows and the estimated disaster zones. The geological hazards such as landslides and debris flows are mainly distributed in the 10 km buffer zone of faults, and most of them occur in the zones with the heights of 500-800 m and the slopes of 5°-25°.

Key words: debris flows, environmental factors, geological structural factors, landslide, Miyun Reservoir, occurrence probability estimation, terrain factors