Worksheet for computing annual exceedance probability flood discharges and prediction intervals at stream sites in Connecticut
The U.S. Geological Survey (USGS), in cooperation with Connecticut Department of Transportation, completed a study to improve flood-frequency estimates in Connecticut. This companion data release is a Microsoft Excel workbook for: (1) computing flood discharges for the 50- to 0.2-percent annual exceedance probabilities from peak-flow regression equations, and (2) computing additional prediction intervals, not available through the USGS StreamStats web application. The current StreamStats application (version 4) only computes the 90-percent prediction interval for stream sites in Connecticut. The Excel workbook can be used to compute the 70-, 80-, 90-, 95-, and 99-percent prediction intervals. The prediction interval provides upper and lower limits of the estimated flood discharge with a certain probability, or level of confidence in the accuracy of the estimate. The standard error of prediction for the Connecticut peak-flow regression equations ranged from 26.3 to 45.0 percent (Ahearn and Hodgkins, 2020). The Excel workbook consists of four worksheets. The worksheets provide an overview of how the application works; input and output tables of the explanatory variables and flood discharges, and graphical display of the results; and the computational formulas used to estimate the flood discharges and prediction intervals.
Citation Information
Publication Year | 2020 |
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Title | Worksheet for computing annual exceedance probability flood discharges and prediction intervals at stream sites in Connecticut |
DOI | 10.5066/P9EWHAYW |
Authors | Elizabeth A Ahearn, Andrea G Veilleux |
Product Type | Data Release |
Record Source | USGS Digital Object Identifier Catalog |
USGS Organization | New England Water Science Center |