ABSTRACT
Many streams descending from the mountain ranges in Teton National Forest have aggraded their lower reaches and have built alluvial fans flanking the ranges. The condition of these streams indicates a sediment supply too large to be transported with the available discharge. As a result, deposition of sediment load in the channel forces an alteration of course on practically an annual basis. The hydrologic effect of forest cover on slope stability derives from the fact that trees transpire through their leaves and this, in turn, depletes soil moisture. Soil moisture depletion produces negative pore-water pressure which, as seen earlier, is conducive to slope stability. A forest can also intercept moisture either in the crowns of trees or in the ground litter. A forested slope might not reach critical saturation quickly nor exhibit such high pore water pressures (piezometric levels) after intense storms as a denuded (clear-cut) slope.
