Linked Model to Estimate Stream Bank and Watershed Sediment Loading

In developed urban and some rural areas, sediment in streams is a pervasive, ubiquitous pollutant that poses ecological problems, reducing habitat structure, limiting the potential biotic diversity of the area, and in some cases extirpating sensitive and protected species. One of the functions of a stable stream system is to transport sediment from the watershed in a manner that does not aggrade nor degrade the stream channel. While some rivers have always carried significant loads of sediment (e.g., moraine systems), others are expanding this functional role in response to a variety of human activities in the watershed.Complex watershed models, such as HSPF (Hydrological Simulation Program – FORTRAN) and SWAT (Soil Water Assessment Tool) estimate sediment loads from wash-off processes that are simulated from various land use practices within the watershed. However, few models are currently available to provide an estimate of sediment that is generated from the stream banks of the river channels. This paper presents and discusses a simple linked model that can be used to estimate both stream bank and watershed sediment loading.