thumbnail

Regional landslide-hazard evaluation using landslide slopes, Western Wasatch County, Utah

Environmental and Engineering Geoscience

By:
and

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

Landsliding has historically been one of the most damaging geologic hazards in western Wasatch County, Utah. Accordingly, we mapped and analyzed landslides (slumps and debris slides) in the area to provide an empirical basis for regional landslide-hazard evaluation. The 336 landslides in the 250-sq-mi (650-km2) area involve 20 geologic units, including Mississippian- to Quaternary-aged rock and unconsolidated deposits. Landsliding in western Wasatch County is characterized by a strong correlation between geologic material and landslide-slope inclination. From a simple statistical analysis of overall slope inclinations of late Holocene landslides, we determined "critical" slope inclinations above which late Holocene landsliding has typically occurred and used these as the primary basis for defining relative landslide hazard. The critical slopes vary for individual geologic units and range from 15 to 50 percent (9??-27??). The critical slope values and landslide locations were used in conjunction with geologic and slope maps to construct qualitative landslide-susceptibility maps for use by county planners. The maps delineate areas of low, moderate, and high relative hazard and indicate where studies should be completed prior to development to evaluate site-specific slope-stability conditions. Critical slopes as determined in this study provide a consistent empirical reference that is useful for evaluating relative landslide hazard and guiding land-use-planning decisions in large, geologically complex areas.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Regional landslide-hazard evaluation using landslide slopes, Western Wasatch County, Utah
Series title:
Environmental and Engineering Geoscience
Volume
3
Issue:
1
Year Published:
1997
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental and Engineering Geoscience
First page:
31
Last page:
43
Number of Pages:
13