Simulation of the effects of contour coal strip mining on stormwater response and suspended sediment yield in the New River Watershed, Tennessee

Water and soil are two of man's most valuable resources and often the most abused. The impact of misuse frequently results in dramatic effects such as floods, soil erosion, droughts and unwanted deposition of soil. Repeatedly, these consequences are caused by an inability to quantify the effects of land use changes on stormwater runoff and soil erosion in small watersheds. With this in mind, a mathematical model for simulating stormwater response and suspended sediment yield in strip mined watersheds was developed. This model consisted of a storm hydrograph simulator, a watershed suspended sediment load simulator and a site erosion simulator. The storm hydrograph simulator, TENN-I, has been optimized for the Tennessee Valley and can be used for both gauged and ungauged watersheds. The watershed soil ioad simulator, LOAD-I, was based upon development of a suspended load modulus that can be derived from storm hydrographs and serigraphs. The site specific soil erosion model, ERoDE-I, was based upon soil erosion mechanics and overland flow. Erosion, runoff, sediment delivery and total loads were simulated for storm events on both a real time basis and on a design storm basis. A regionalization scheme associated with the model permitted simulation of the effects of alternative development scenarios on stormwater and suspended load. Comparisons of the model are made with suspended sediment yields from watersheds which have undergone coal contour strip mining and urbanization.

This model's ability to relate a watershed's stormwater runoff and sediment load to measurable, quantifiable, and readily comparable quantities provides a powerful tool to evaluate the effects of land use change before the fact.