Peak-flow frequency analysis for seven selected U.S. Geological Survey streamgages in the Floyd and Little Sioux River Basins, Iowa, based on data through water year 2019

This data release presents peak-flow frequency analyses by the U.S. Geological Survey based on methods described by Eash and others (2013) for streamgages 06600100, Floyd River at Alton, Iowa; 06600300, West Branch Floyd River near Struble, Iowa; 06600500, Floyd River near James, Iowa; 06605000, Ocheyedan River near Spencer, Iowa; 06605850, Little Sioux River at Linn Grove, Iowa; 06607200, Maple River at Mapleton, Iowa; and 06607500, Little Sioux River near Turin, 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 analyses for these streamgages were retrieved from the U.S. Geological Survey National Water Information System database (U.S. Geological Survey, 2020) and used with USGS flood-frequency analysis software PeakFQ (Veilleux and others, 2014). This data release contains annual peak-flow data (floyd_ffa_2019_WATSTORE.txt), PeakFQ specifications (floyd_ffa_2019.psf), and a series of tables describing the methods and results of the peak-flow frequency analysis (floyd_ffa_2019.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, 2020, USGS water data for the Nation: U.S. Geological Survey National Water Information System database, accessed June 25, 2020, 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.

本数据集发布内容为美国地质调查局（U.S. Geological Survey, USGS）基于Eash等人（2013）提出的方法，针对以下7个水文站开展的洪峰流量频率分析：爱荷华州奥尔顿市弗洛伊德河水文站（06600100）、爱荷华州斯特布尔附近西支流弗洛伊德河水文站（06600300）、爱荷华州詹姆斯附近弗洛伊德河水文站（06600500）、爱荷华州斯宾塞附近奥奇耶丹河水文站（06605000）、爱荷华州林恩格罗夫小苏河水文站（06605850）、爱荷华州梅普尔顿市梅普尔河水文站（06607200）、爱荷华州图林附近小苏河水文站（06607500）。该方法用于估算50%、20%、10%、4%、2%、1%、0.5%及0.2%年超越概率（annual exceedance probabilities, AEPs）对应的洪峰流量分位数。本次洪峰流量频率分析所用的年度洪峰流量数据，取自美国地质调查局国家水信息系统数据库（U.S. Geological Survey, 2020），并结合USGS洪水频率分析软件PeakFQ（Veilleux等人，2014）完成分析。本数据集包含以下文件：年度洪峰流量数据文件（"floyd_ffa_2019_WATSTORE.txt"）、PeakFQ配置文件（"floyd_ffa_2019.psf"），以及一系列阐述洪峰流量频率分析方法与结果的数据表（"floyd_ffa_2019.xlsx"）。参考文献：1. Eash, D.A., Barnes, K.K. 及 Veilleux, A.G.，2013，《基于2010水年数据的爱荷华州河流年超越概率流量估算方法》：美国地质调查局科学调查报告2013-5086，共63页（含附录），http://pubs.usgs.gov/sir/2013/5086/。2. U.S. Geological Survey，2020，《美国全国水数据：美国地质调查局国家水信息系统数据库》，2020年6月25日访问，https://doi.org/10.5066/F7P55KJN。3. Veilleux, A.G., Cohn, T.A., Flynn, K.M., Mason, R.R., Jr. 及 Hummel, P.R.，2014，《使用PeakFQ 7.0程序估算洪水量级与频率》：美国地质调查局情况说明书2013-3108，共2页，https://dx.doi.org/10.3133/fs20133108。