Hillslope Treatment Effectiveness and Performance Characteristics Summary Chart

This table is from Appendix A of GTR-240, Post-Fire Treatment Effectiveness for Hillslope Stabilization.

Summary: This synthesis of post-fire treatment effectiveness reviews post-fire hillslope emergency stabilization treatment research and monitoring with an emphasis on the past decade. Since 2000, erosion barrier treatments (contour-felled logs, straw wattles), which were a mainstay of post-fire management prior to 2000, have declined in use for hillslope stabilization. At the same time, mulching treatments are increasingly being applied when values-at-risk warrant protection. This change has been motivated by research that shows the proportion of exposed mineral soil (or, conversely, the proportion of ground cover) to be the primary factor in the amount of post-fire hillslope erosion. Erosion barrier treatments provide little ground cover and have been shown to be less effective than mulch, especially during short-duration high-intensity rainfall events. Innovative options for producing and applying mulch materials have made it possible to apply ground cover over large burned areas that are inaccessible by road. Although longer-term studies on mulch treatment effectiveness are still on-going, early results and short-term studies have shown dry mulches (agricultural straw, wood chips, wood shreds, etc.) to be highly effective post-fire hillslope stabilization treatments. Consequently, mulch treatments have become commonplace in the post-fire environment to provide protection to high values-at-risk. Hydromulches, and to a lesser degree, soil binding chemical treatments, have been used after some fires but these treatments have been less effective than dry mulches in stabilizing burned hillslopes and generally decompose or degrade within a year.