Sediment production and downslope sediment transport from forest roads in granitic watersheds

Abstract

A mapping technique was used to measure the annual downslope deposition of granitic sediments eroded from forest roads on three headwater watersheds in the mountains of central Idaho. Frequency distributions were developed to determine sediment travel distance, and a dimensionless relationship was developed to describe the relation between the percentage of total volume and total length of sediment deposit. By combining the two relations, land managers can assess the risk of sediment reaching streams to help guide road location and design.