Peak-flow frequency analysis for U.S. Geological Survey streamgage 06810000 Nishnabotna River above Hamburg, Iowa, in the Nishnabotna River Basin, Iowa, based on data through water year 2020

This data release presents a peak-flow frequency analysis (Eash and others, 2013) for U.S. Geological Survey streamgage 06810000 Nishnabotna River above Hamburg, Iowa. These methods are used to provide estimates of peak-flow quantiles for 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs). Annual peak-flow data used in the peak-flow frequency analysis for this streamgage was retrieved from the U.S. Geological Survey National Water Information System database (U.S. Geological Survey, 2021) and used with USGS flood-frequency analysis software PeakFQ (Veilleux and others, 2014). This data release contains annual peak-flow data (nishnabotna_2020_WATSTORE.txt), PeakFQ specifications (nishnabotna_ffa_2020.psf), and a series of tables describing the methods and results of the peak-flow frequency analysis (nishnabotna_ffa_2020.xlsx). References Cited: Eash, D.A., Barnes, K.K., and Veilleux, A.G., 2013, Methods for estimating annual exceedance-probability discharges for streams in Iowa, based on data through water year 2010: U.S. Geological Survey Scientific Investigations Report 2013-5086, 63 p. with appendix., http://pubs.usgs.gov/sir/2013/5086/. U.S. Geological Survey, 2021, USGS water data for the Nation: U.S. Geological Survey National Water Information System database, accessed March 10, 2021, at https://doi.org/10.5066/F7P55KJN. Veilleux, A.G., Cohn, T.A., Flynn, K.M., Mason, R.R., Jr., and Hummel, P.R., 2014, Estimating magnitude and frequency of floods using the PeakFQ 7.0 program: U.S. Geological Survey Fact Sheet 2013?3108, 2 p., https://dx.doi.org/10.3133/fs20133108.