Evaluating and modeling flood potential in ungaged high relief basins in East Tennessee : a hydrogeomorphic approach

Flooding is a natural event that can be hazardous, especially when it occurs in areas of human occupance. Research on flooding has increased in recent years, but data are scarce for many small watersheds, including many that have frequent flash flood events. This research focuses on flood potential in East Tennessee, where small, high relief basins along the Cumberland Plateau have historically experienced severe flooding. Based on the physical characteristics of their watersheds, I expected three of these streams, Roaring Creek, Richland Creek and the Piney River to have a high level of unrecognized flood potential. While flood risk is based strictly on statistical probability of occurrence, flood potential encompasses all watershed factors: climatic, hydrologic and geomorphic.

Because of their importance to land use planning, basin-specific data are critically needed. This research uses a basinwide approach to analyze watershed characteristics, rainfall-runoff ratios and storm hydrographs. Research results are incorporated into a Hydrogeomorphic Flood Potential model that includes 24 natural basin characteristics and 12 human-based factors. The model is used to evaluate streams separately and to make comparisons between streams. It confirms that Roaring Creek and Richland Creek have high flood potential, but indicates that the Piney River is in a more critical situation.

I reached three major conclusions from this research. First, study streams that flow off the plateau do indeed exhibit high flood potential. Second, there is an urgent and important need for continued research of this type. Application of the Flood Potential Model would be both practical and valuable in other small ungaged basins. Last, but not least, the results of this research seriously question the effectiveness of conventional floodplain management in small, high relief basins.