Book Description

Successful management of water in mountain streams by the USDA Forest Service requires that the link between resource development and channel change be documented and quantified. The characteristics of that linkage are unclear in mountain streams, and the adjustability of these streams to land-use and hydrologic change has been argued in court. One way to quantify the adjustability of a stream is to examine its geomorphic history. An excellent source of historic geomorphic data are the records associated with stream gaging stations maintained by the U.S. Geological Survey. This report describes what records are available, how to organize the data on computer spreadsheets, and discusses 6 techniques that quantify the spatial and temporal magnitude of historic channel adjustments. The discharge measurements include physical measurements of the channel. In particular, USGS discharge measurements include physical measurements of the channel. By analyzing these measurements collectively, it is possible to quantify monthly, annual, and decadal scales of adjustment. Once the history of channel adjustment is determined, it can be compared to histories of climate change, flow regulation, and land use. These comparisons may link the geomorphic adjustments to particular patterns, events, or activities. Resource managers can use this knowledge to better assess the ramifications of resource development, land use, and restoration efforts on mountain stream systems.