Monitoring timber harvest impacts on stream sedimentation: Instream vs. upslope methods

Abstract

There is increasing pressure on forest managers and natural resource professionals to measure, monitor, and evaluate stream sediment production from timber harvest activities. However, the great expense of instream sediment monitoring severely limits the number of monitoring projects which can be undertaken and has hindered the development of regulations to maintain water quality. The purpose of this study was to compare instream vs. upslope monitoring on three experimental clearcuts in northeast Washington State. The upslope monitoring approach tested in this study appeared to circumvent most problems associated with instream monitoring and provided a clear physical linkage between measurements and on-site processes. However, on-site observations indicated that important sedimentation events were unaccounted for by both instream and upslope monitoring. It was concluded that qualitative observations can also be important tools for monitoring the effects afforest management activities on sediment production and delivery.