Generalized least-squares WREG regression files for Hawaiʻi flood-frequency analysis, based on data through water year 2020
Dates
Publication Date
2023-04-28
Time Period
2023
Citation
Mitchell, J.N., and Wagner, D.M., 2023, Data in support of flood-frequency report—Magnitude and Frequency of Floods on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, Based on Data through Water Year 2020: U.S. Geological Survey data release, https://doi.org/10.5066/P9GGPPV5.
Summary
The U.S. Geological Survey (USGS), in cooperation with the State of Hawaiʻi Department of Transportation, estimated flood magnitudes for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEP) for unregulated streamgages in Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, using data through water year 2020. Regression equations which can be used to estimate flood magnitude and associated frequency at ungaged streams were developed. The methods and results of the study are published in a separate report (https://doi.org/10.3133/sir20235014). This data release contains (1) a folder with the PeakFQ output files for each streamgage, ".PRT" and ".EXP" files, for use in the USGS weighted-multiple-linear [...]
Summary
The U.S. Geological Survey (USGS), in cooperation with the State of Hawaiʻi Department of Transportation, estimated flood magnitudes for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEP) for unregulated streamgages in Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, using data through water year 2020. Regression equations which can be used to estimate flood magnitude and associated frequency at ungaged streams were developed. The methods and results of the study are published in a separate report (https://doi.org/10.3133/sir20235014). This data release contains (1) a folder with the PeakFQ output files for each streamgage, ".PRT" and ".EXP" files, for use in the USGS weighted-multiple-linear regression (WREG) program; (2) a tab-delimited text file that contains the basin characteristics for use in the USGS WREG program; and (3) a folder with the output from the USGS WREG program, with results separated into folders for each regression region and selected AEP. These data can be used to reproduce the regression results in the larger work: Magnitude and Frequency of Floods on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, Based on Data through Water Year 2020.
The files in this data release are provided as a public service such that the results of the larger work can be reproduced. The purpose of the larger work is to present methods and results for estimating the magnitude and frequency of floods for unregulated streams on five of the main Hawaiian Islands: Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi. (Unregulated streams are those for which peak flows are not altered to a large extent by upstream reservoirs, dams, diversions, or other structures.) The report describes (1) updated flood flows at selected streamgages for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs) using peak-flow data through water year 2020; (2) regional-skew estimates for Hawaiʻi; (3) regression equations for relating basin and climatic characteristics to flood flows at ungaged stream sites for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent AEPs; and (4) the accuracy and limitations of the regression equations. The regression equations developed were incorporated in the web-based USGS StreamStats application for Hawaiʻi.
