The intense, prolonged rainfall of October 29-31, 1998, from Hurricane Mitch triggered more than 200 landslides in and around Tegucigalpa, Honduras. Landslides triggered by Hurricane Mitch within the Tegucigalpa area are documented
as a 1:10,000-scale landslide inventory map. The landslide source areas on this map indicate the least stable slopes within the Tegucigalpa area during the rainfall conditions that existed during Hurricane Mitch. All but four landslides in this inventory were debris flows that mobilized from relatively shallow soil slides originating within colluvium or weathered bedrock. These four landslides are deep-seated slump/earth flows and debris slides.
The purpose of this report and accompanying maps is to quantitatively estimate the susceptibility and hazard of slopes within the metropolitan area of Tegucigalpa to future debris flows from an extreme event such as Hurricane Mitch. To do this, we use a Geographic Informations Systems (GIS) analysis based on a simple limit-equilibrium model of an infinite slope in materials having both frictional and cohesive strength. By comparing landslides triggered by Hurricane Mitch in the metropolitan area of Tegucigalpa, Honduras with the results of a regional GIS-based slope-stability analysis, we establish relative hazard categories for future landslide occurrence.
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