A geographical model of erosion for field managers to complement existing process models.

摘要

Process studies have received the lion's share of attention among researchers in fluvial geomorphology. Unfortunately, process studies are time consuming, require advanced technology, and cover relatively short time periods. In addition, most process studies are of limited practical use to the majority of resource managers. Individuals working in the resource management arena do not have a robust and practical model for predicting change, a model solidly grounded in current theory, and, at the same time, useable in a field setting. Rather, they are forced to rely on the costly and time-consuming services of highly trained hydrologists and geomorphologists in all situations, even those where a rough estimate would be sufficient.; An innovative methodological approach is needed, one that gives researchers and resource managers the ability to integrate different temporal and spatial scales. This approach should facilitate the integration of images captured across the remote sensing continuum and must allow for retrodiction as well as prediction. The ability to calculate probability of erosion would provide many who manage fields and streams a practical way of estimating what impacts future actions on their parts might have. Unfortunately, this is a major void in research dealing with fluvial geomorphology. This dissertation fills that void.; Using ArcInfo™, a popular geographic information systems software package, erosion of streambanks and mid-channel islands of a section of the Snake River in Grand Teton National Park, Wyoming, was measured for two time periods. From that data, erosion probabilities were calculated. A 5 th-degree polynomial was fit to the data points and models with R 2 > 0.95 were constructed.; In an appendix to the dissertation a “user-friendly” protocol is published. It details the steps a field manager should follow in order to establish probabilities of erosion that could be expected given the geography and geometry of the floodplain under consideration. Using digital orthophotos and/or un-rectified digital aerial photographs, the field manager can estimate the channel's planform movement from his or her office and with a bare minimum of fieldwork. Using this protocol, the field manager can determine whether a full-blown geomorphic study would be warranted.