Major floods, poor land use delay return of sedimentation to normal rates

Abstract

Recovery from flood-accelerated sedimentation affects both estimates of long-term average deposition and short-term monitoring of changes. "Years to return to normal" for 10 watersheds in northern California after a major flood accelerated sediment concentrations were analyzed. Returns to normalcy took from 0 to 9 years; rate of decline was related to both amount of initial acceleration by the flood and differences in watersheds. years to recovery increased with these four factors: coefficient of path lengths in the watershed, area of poor logging, area of steep grassland, and percent of area in sedimentary rock types Cenozoic or younger.

Citation

Anderson, Henry W. 1972. Major floods, poor land use delay return of sedimentation to normal rates. Res. Note PSW-RN-268. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 4 p