Investigation of trends in flooding in the Tug Fork basin of Kentucky, Virginia, and West Virginia

Statistical analysis indicates that the average size of annual flood peaks of the Tug Fork (West Virginia and Kentucky) has been increasing. However, additional statistical analysis does not indicate that flood levels exceeded typically once or twice a year in the period 1947-1979 are any more likely to be exceeded now than in 1947. Possible trends in stream-channel size are also investigated at three locations. No discernable trends in channel size are noted. Further statistical analysis of the trend in the size of annual flood peaks shows that much of the annual variation is related to nearby rainfall and to the "natural" hydrologic response in a relatively undisturbed sub-basin. However, some statistical indication of trend persists after accounting for these natural factors, though the indication is of borderline statistical significance. This suggests the need for further study in the basin that may relate flood magnitudes to both rainfall and to land use.