A distributed slope stability model for steep forested basins

摘要: A distributed, physically based slope stability model (dSLAM), on an infinite model, a kinematic wave groundwater and continuous change vegetation root strength is presented. It integrated with contour line-based topographic analysis geographic information system (GIS) for spatial data extraction display. The can be run either individual rainfall events or long-term sequences of storms. These inputs actual storm records synthesized random Monte Carlo simulation. designed to analyze rapid, shallow landslides the distribution safety factor (FS) in steep, forested areas. investigate problem both temporal dimensions, example, impact timber harvesting at given time through extended management period, probability landslide occurrence year, delivery sediments headwater streams. dSLAM was applied drainage Cedar Creek Oregon Coast Ranges using patterns measured during major which triggered widespread that area 1975. Simulated volume number failures were 733 m3 4, respectively. values agreed closely field measurements following 1975 storm. However, effect parameter uncertainty may complicate this comparison. For when soil cohesion 2.0 3.0 kPa used, failure changed by factors 2.04 0.41, respectively, compared average condition 2.5 used depths 30% higher lower than standard condition, 0.27, When maximum from 12.5 (average condition) 10 kPa, increased 1.73-fold; case 15 0.55. simulated caused mostly hollows. simulations show FS controlled mainly topography timber-harvesting greatly affected flow rainstorms. Most areas < corresponded blocks clear-cut 1968, all elements 1968. Areas low (1.0–1.6) expanded dramatically rainstorm decreased slow rate after Factors hollows declined sharply