Comparison of peak-flow estimation methods for small drainage basins in Maine

• DOI: 10.3133/sir20075170
• Publication Date: 2018-08-15T18:35:07Z
• Authors: Glenn A. Hodgkins; Charles Hebson; Pamela J. Lombard; Alexander Mann
• Keywords: Square (algebra); Culvert

Understanding the accuracy of commonly used methods for estimating peak streamflows is important because designs bridges, culverts, and other river structures are based on these flows. Different were analyzed small drainage basins in Maine. For smallest basins, with areas 0.2 to 1.0 square mile, nine from actual rainfall events at four crest-stage gaging stations modeled by Rational Method Natural Resource Conservation Service TR-20 method compared observed The had a root mean error (RMSE) -69.7 230 percent (which means that approximately two thirds flows within flows). an RMSE -98.0 5,010 percent. Both underestimated most cases. 10 miles, statistical return periods 2, 50, 100 years 17 streams Maine adjoining parts New Hampshire. Peak Method, Resources method, U.S. Geological Survey regression equations, Probabilistic Method. equations accurate computing miles -34.3 52.2 50-year was next (-38.5 62.6 percent). (-56.1 128 percent) particularly (-76.4 323 much larger errors. similar numbers underpredictions overpredictions. overpredicted tended overpredict smaller (less than 5 miles) underpredict basins. results this study consistent comprehensive analysis United States, which 70 Midwest Northwest.