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USGS2022

Yucaipa valley integrated hydrological model

Introduction The hydrologic system in the Yucaipa Valley watershed (YVW) was simulated using the coupled Groundwater and Surface-water FLOW model (GSFLOW; Markstrom and others, 2008). This study uses version 2.0 of GSFLOW, which is a combination of the Precipitation-Runoff Modeling System (PRMS; Markstrom and others, 2015), and the Newton-Raphson formulation of the Modular Groundwater-Flow Model (MODFLOW-NWT; hereafter referred to as MODFLOW; Harbaugh, 2005; Niswonger and others, 2011). GSFLOW partitions the hydrologic system into three regions (fig. B1) that are linked by the exchange of unsaturated and saturated groundwater and surface water. The properties and processes within each region influence the flow of both groundwater and surface water into, out of, and within each region. The PRMS component of GSFLOW simulates Region 1, and the MODFLOW component simulates Regions 2 and 3. In the YVW, GSFLOW was applied as the simulation code and is referred to herein as the Yucaipa Integrated Hydrologic Model (YIHM; Alzraiee and others, 2022). In the YIHM, Region 1 includes the plant canopy, snowpack, and the soil zone; Region 2 includes the stream network; and Region 3 includes the subsurface beneath Regions 1 and 2 and consists of both the saturated and unsaturated zones. Soil-moisture conditions and head relations control the flow of both groundwater and surface water between regions. The maximum lateral extents of Regions 1 and 3 were defined using the surface-water drainage divides described in the “Description of Study Area” section of chapter A of this report. The boundaries for Region 2 are the lowest elevation of the streambeds, the stream channel widths, and the horizontal extent of the stream channels in the YVW. Flow across the unsaturated part of Region 3 is assumed to be vertical and does not cross the lateral boundary. To simulate hydrologic processes occurring within the YVW using GSFLOW, a model domain was defined to match the surface watershed such that the domain includes each surficial hydrologic unit coinciding (at least partially) with the Yucaipa groundwater subbasin (hereafter referred to as “Yucaipa subbasin”) as defined in California Bulletin 118 (California Department of Water Resources, 2016). The resulting simulated domain (fig. B2) includes the Yucaipa subbasin and intersects partially with parts of the San Bernardino and San Timoteo groundwater subbasins (fig. B2). The area of the active model domain in YIHM is about 121 square miles (mi2). The developed YIHM can be used to improve understanding of the hydrologic processes in YVW and to simulate future management scenarios with different climatic and anthropogenic changes.

Scientific Investigations Report↗

USGS2022

Peak-flow and low-flow magnitude estimates at defined frequencies and durations for nontidal streams in Delaware

Reliable estimates of the magnitude of peak flows in streams are required for the economical and safe design of transportation and water conveyance structures. In addition, reliable estimates of the magnitude of low flows at defined frequencies and durations are needed for meeting regulatory requirements, quantifying base flows in streams and rivers, and evaluating time of travel and dilution of toxic spills. This report, in cooperation with the Delaware Department of Transportation and the Delaware Geological Survey, presents methods for estimating the magnitude of peak flows and low flows at defined frequencies and durations on nontidal streams in Delaware, at locations both monitored by streamflow-gage sites and ungaged. Methods are presented for estimating (1) the magnitude of peak flows for return periods ranging from 2 to 500 years (50-percent to 0.2-percent annual-exceedance probability), and (2) the magnitude of low flows as applied to 7-, 14-, and 30-consecutive day low-flow periods with recurrence intervals of 2, 10, and 20 years (50-, 10-, and 5-percent annual non-exceedance probabilities). These methods are applicable to watersheds that exhibit a full range of development conditions in Delaware. The report also describes StreamStats, a web application that allows users to easily obtain peak-flow and low-flow magnitude estimates for user-selected locations in Delaware. Peak-flow and low-flow magnitude estimates for ungaged sites are obtained using statistical regression analysis through a process known as regionalization, where information from a group of streamflow-gage sites within a region forms the basis for estimates for ungaged sites within the same region. Ninety-four streamflow-gage sites in and near Delaware with at least 10 years of nonregulated annual peak-flow data were used for the peak-flow regression analysis, a subset of the 121 sites for which peak-flow estimates were computed. These sites included both continuous-record streamflow-gage sites as well as partial record sites. Forty-five streamflow-gage sites with at least 10 years of nonregulated low-flow data available were used for the low-flow regression analyses, a subset of the 68 sites for which low-flow estimates were computed. Estimates for gaged sites are obtained by combining (1) the station peak-flow statistics (mean, standard deviation, and skew) and peak-flow estimates using the recent Bulletin 17C guidelines that incorporate the Expected Moments Algorithm with (2) regional estimates of peak-flow magnitude derived from regional regression equations and regional skew derived from sites with records greater than or equal to 35 years. Example peak-flow estimate calculations using the methods presented in the report are given for (1) ungaged sites, (2) gaged sites, (3) sites upstream or downstream from a gaged location, and (4) sites between gaged locations. Estimates for low-flow gaged sites are obtained by combining (1) the station low-flow statistics (mean, standard deviation, and skew) and low-flow estimates with (2) regional estimates of low-flow magnitude derived from regional regression equations. Example low-flow estimate calculations using the methods presented in the report are given for (1) ungaged sites, (2) gaged sites, (3) sites upstream or downstream from a gaged location, and (4) sites between gaged locations. A total of 54 sites in the Coastal Plain region were used to develop peak-flow regressions for the region and 40 sites were used for the Piedmont region. Similarly, 24 sites were used for low-flow regression equation development in the Coastal Plain, with 21 in the Piedmont. Peak and low-flow site inclusion in the Coastal Plain tended to be more restricted with tidal influence and ranges of basin characteristics, including drainage area, limiting regression equation development and application. Regional regression equations for peak flows and low flows, as applicable to ungaged sites in the Piedmont and Coastal Plain Physiographic Provinces in Delaware, are presented. Peak-flow regression equations used variables that quantified drainage area, basin slope, percent area with well-drained soils, percent area with poorly drained soils, impervious area, and percent area of surface water storage in estimating peak-flow estimates, whereas low-flow regression equations used only drainage area and percent poorly drained soils in the estimation of low flows. Average standard errors for peak-flow regressions tended to be lower than those for low- flow regressions, with lower errors in the Piedmont region for both peak- and low-flow regressions. For peak-flow estimates, a sensitivity analysis of Piedmont regression equation estimates to changes in impervious area is also presented. Additional topics associated with the analyses performed during the study are discussed, including (1) the availability and description of 32 basin and climatic characteristics considered during the development of the regional regression equations; (2) the treatment of increasing trends in the annual peak-flow series identified at 18 gaged sites and inclusion in or exclusion from the regional analysis; (3) regional skew analysis and determination of regression regions; (4) sample adjustments and removal of sites owing to regulation and redundancy; and (5) a brief comparison of peak- and low-flow estimates at gages used in previous studies.

Delaware↗

USGS2023

Magnitude and frequency of floods on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, based on data through water year 2020

Accurate estimates of flood magnitude and frequency are needed to (1) optimize the design and location of infrastructure, including dams, culverts, bridges, industrial buildings, and highways, and (2) inform flood-zoning and flood-insurance studies. 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 were developed to estimate flood magnitude and associated frequency at ungaged streams. This study improves upon a previous USGS flood-frequency report (Oki and others, 2010) by including more peak-flow data, implementing new statistical methods in flood-frequency analysis, and using updated techniques to estimate the regional-skewness coefficient (regional skew). Flood magnitude and frequency at 238 streamgages were estimated—following national guidelines established in Bulletin 17C (England and others, 2019)—by fitting annual peak-flow data to the Log-Pearson Type III distribution using the expected moments algorithm and the PeakFQ flood-frequency software. Potentially influential low outliers in the data were identified and removed using the Multiple Grubbs-Beck Test. An updated regional skew for Hawaiʻi was estimated using the Bayesian weighted least squares/Bayesian generalized least squares method. The updated regional skew employs a constant model for the five islands in the study area and has a value of −0.157 (mean square error of 0.212). Multiple linear regression techniques were used to develop regression equations that relate basin and climatic characteristics to peak flows at streamgages. The regression equations can be applied to estimate flood magnitude and frequency at ungaged sites. The study area was split into 10 regions—2 regions per island, generally following a leeward/windward division—containing from 9 to 49 streamgages each. The final regression equations for each region were determined with generalized least-squares analysis using the USGS weighted-multiple-linear regression (WREG) program. The standard error of prediction at the 1-percent AEP for the regression equations ranged from 18 to 164 percent; the pseudo coefficient of determination (pseudo-R2) at the 1-percent AEP ranged from 46 to 100 percent. The regression equations performed well for all regions except leeward Molokaʻi and southern Island of Hawaiʻi; for all other regions, the pseudo-R2 values ranged from about 75 to 100 percent. Compared to the regression equations developed by Oki and others (2010), the regression equations in this study generally showed modest improvements, although the magnitude of differences varied for each region. Peak-flow estimates at the 238 streamgages included in this study are improved by weighting the at-site statistics computed with PeakFQ and the predicted flows based on the regression equations. Results of this study—including the final peak-flow estimates at streamgages and the regional regression equations—are implemented in the USGS StreamStats web application (U.S. Geological Survey, 2023, StreamStats: https://streamstats.usgs.gov/ss/ ). StreamStats provides a consistent approach for obtaining peak-flow estimates at streamgages and for applying the regional regression equations for estimating peak flows at ungaged locations.

Hawaii↗

USGS2024

Estimation and comparison of 1-percent annual exceedance probability flood flows at Federal Emergency Management Agency flood insurance study flow locations across Pennsylvania

Flood-flow estimates were computed at over 5,000 Federal Emergency Management Agency (FEMA) flood insurance study (FIS) flow locations across Pennsylvania for the 1-percent annual exceedance probability flood event (1-percent AEP). Depending on a point of interest’s proximity to a streamgage, weighting techniques may be applied to obtain flood-flow estimates for ungaged flow locations using observed peak-flow data from a nearby streamgage. Following the U.S. Geological Survey’s (USGS) published guidance, stream segments were identified where the drainage-area ratio method could be leveraged. Using updated regional regression equations and recently published flood-flow estimates at USGS streamgage locations following USGS Bulletin 17C guidelines, weighted and transferred flood flows were computed, where appropriate. For locations not applicable for the drainage-area ratio method, regression equations were used to compute flood-flow estimates. These flood-flow estimates were then compared to FEMA FIS 1-percent AEP flood-flow estimates. Percentage-difference values were computed for 3,599 FIS flow locations determined to be suitable for analysis, finding that USGS-derived flood-flow estimates were consistently lower than FEMA FIS flood-flow estimates with a statewide median percentage difference of −10.1 percent. The dataset was normally distributed with a standard deviation of 45.7 percent. Allegheny County was found to have 74 FIS flow locations with percentage-difference values greater than or equal to 67 percent or less than or equal to −67 percent. The flood-flow region in which Allegheny County is contained, Region 2, had a median percentage-difference value of −39 percent. Although removed from the final analysis, flow locations with drainage-area values above the recommended threshold for regression-based estimation (about 1,000 square miles [mi 2 ]) were observed to have consistently higher percentage-difference values; a reminder of the limitations of use for regression-based flood-flow estimates. This report, the comparisons within, and a companion data release are intended to serve as tools to FEMA in assisting with the ongoing assessment of FIS flow locations across Pennsylvania.

Pennsylvania↗

USGS2025

Estimating the magnitude and frequency of floods at ungaged locations on streams in Tennessee through the 2013 water year

To improve estimates of the frequency of annual peak flows for ungaged locations on non-urban, unregulated streams in Tennessee, generalized least-squares multiple linear-regression techniques were used to relate annual peak flows from streamgages operated by the U.S. Geological Survey to physical, climatic, and land-use characteristics of their drainage basins. Geospatial data acquired since the previous study in 2003, annual peak-streamflow data through the 2013 water year, and Bulletin 17C methods for frequency analysis of annual peak-streamflow data were used in the study. Generalized least-squares regression equations were developed for four hydrologic areas with distinct hydrologic, geologic, and topographic characteristics. Drainage area was used as an explanatory variable in equations developed for each hydrologic area. In addition to drainage area, a 2-year recurrence-interval climate factor was used for hydrologic area 1, a 10–85 channel slope was used for hydrologic area 2, and percent imperviousness was used for hydrologic area 4. The regression equations can be used to estimate annual exceedance probability streamflows for ungaged locations on non-urban, unregulated streams in Tennessee. The term “unregulated” indicates that streamflow is not appreciably influenced by regulation from reservoirs or other impoundments. Average standard errors of prediction for the regression equations ranged from 44.4 to 51.4 percent for hydrologic area 1; 30.4 to 42.9 percent for hydrologic area 2; 35.7 to 42.6 percent for hydrologic area 3; and 32.5 to 47.4 percent for hydrologic area 4.

Tennessee↗

USGS1952

Topical index and bibliography of U.S. Geological Survey Trace Elements and related reports

Part 1, the topical index, lists the titles of reports prepared from 1941 to December 1952, in conjunction with the Geological Survey's program of uranium and other elements of related interest. It includes not only completed Trace Elements reports and those now in preparation, but also Survey publications, publications by Survey personnel in scientific journals, and open-fie releases. The titles are grouped topically under the headings listed in the table of contents. Entries in each category are listed alphabetically, by author, and numbered consecutively. Many of the reports have been cross-indexed, where appropriate. The classification of the Trace Elements reports, insofar as it is known, has been indicated after the title of the report. The classification of some of the earlier Trace Elements reports is uncertain. The Geological Survey does not have additional copies of most of the reports listed, but copies of some of the completed reports can be loaned on request to organizations officially cooperating with the Atomic Energy Commission. Many Trace Elements reports have been made available to the public, either by open-file release, reproduction by Technical Information Service, Oak Ridge (referred to as TIS), by publication as a Geological Survey circular or bulletin or by a publication in a scientific journal. This information is given, following the title of the report. If the abstract of a Trace Element report has been published in Nuclear Science Abstracts, it is noted by the initials NSA following the title of the report. Part 2 is a reference guide to information on the Trace Elements program that is available to the public. This information is categorized according to the type of publication or release.

Trace Elements Investigations↗

USGS1954

U.S. Geological Survey Trace Elements and related reports through 1953

This report combines and brings up-to-date the information previously given in Trace Elements Investigations Report 325, "Numerical list of U.S. Geological Survey Trace Elements Reports to April 30, 1953," and Trace Elements Investigations Report 301, "Topical index and bibliography of U.S. Geological Survey Trace Elements and related reports." Part I is a numerical list of U.S. Geological Survey Trace Elements Investigations and Memorandum reports. It supersedes TEI-325. This part lists not only reports (followed by a date) that have been transmitted to the U.S. Atomic Energy Commission, but also reports in preparation (followed by an asterisk) for which tentative titles were available on December 31, 1953. Reports that have been published are indicated by the abbreviation of the medium of publication. (See also part II.) Part II is a reference guide to Trace Elements and related reports that are available to the public; this part supersedes Part 2 of the TEI-301 (published as Geological survey Circular 281). These reports are grouped according to the type of publication or release. Abstracts published in Nuclear Science Abstracts are not included in Part II, although certain TEI and TEM reports, the abstracts of which have been published in NSA, are so indicated in Part I. Publications in process on December 31, 1953, are designated by an asterisk. Part III is a finding list of states, areas, and subjects. It is based on information derived mostly from the titles of reports and, where titles are of a general nature, from a cursory review of the reports. This list is not a complete index of the information given in Trace Elements and related reports, but is designed to find subjects of major interest. Because of the numerous entries for Colorado and Utah, information has been listed by counties and, where possible, by subject under these states. Other states have county listings only if a county is included in the title of a report; otherwise, areas may be listed separately under the state. Major subjects are listed separately in the index and also where appropriate under states. Analytical methods and subjects related to analytical research are listed under Analytical Methods and Research, but not separately throughout the index. Most mineralogic studies are included under the heading Mineralogy, but are not necessarily listed according to location. Part IV is a finding list of authors. The words “with” and “and” are used to indicate seniority of authorship. For example, a listing of Jones and Brown indicates that Jones is the senior author. A listing of Jones with Brown indicates that Brown is the senior author. In both parts III and IV all Trace Elements reports are listed, as well as other related reports that have not been issued as Trace Elements reports. The following standard abbreviations have been used: TEI, Trace Elements Investigations report; TEM, Trace Elements Memorandum report; P, Professional Paper; B, Bulletin; C, Circular; J, Journal; OF, open file; TIS, Technical Information Service release; NSA, Nuclear Science Abstracts; QM, Quadrangle Map Series; and OM, Oil and Gas map or Mineral Investigations map or report.

Trace Elements Investigations↗

USGS1956

Bibliography and index of U.S. Geological Survey trace elements and related reports through June 1956

This bibliography supersedes TEI-500, "U. S. Geological Survey Trace Elements and related reports through 1954." Part I is a numerical list of U. S. Geological Survey Trace Elements Investigations and Memorandum reports. This part lists reports that have been transmitted to the U. S. Atomic Energy Comission and also reports in preparation (followed by an asterisk) for which tentative titles were available on June 30, 1956. If a report or part of a report has been published, the fact is indicated by the abbreviation of the medium of publication. (See also Part II.) Part II is a reference guide to Trace Elements and related reports that are available to the public. (Part II supersedes Part I of Bulletin 1019-B.) These reports are grouped according to type of publication or release. If a report or part of a report has been published in more than one form, corss-references indicate the other forms of publication. Publications in preparation or in press on June 30, 1956, are designated by an asterisk. Part III is an author index. The words "with" and "and" are used to indicate seniority of authorship. For example, a listing of Black and White indicates that Black is the senior author. A listing of Black with White indicates that White is the senior author. Part IV is an index for finding reports on specific areas or subjects. Information for the index was taken from titles, tables of contents, and abstracts of unpublished reports and from titles of published reports. The index in TEI-500 was used as a guide.

Trace Elements Investigations↗

USGS2002

Flow-frequency characteristics of Vermont streams

The safe and economical design of infrastructure in and near waterways and the effective management of flood-hazard areas require information on streamflow that may not be readily available. This report provides estimates of flow-frequency characteristics for gaged streams in Vermont and describes methods for estimating flow-frequency characteristics for ungaged streams. The flow-frequency characteristics investigated are the magnitude of peak discharges at recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years, and the magnitude of daily-mean discharges exceeded 25, 50, and 75 percent of the time. Peak-flow frequency characteristics for gaged streams were computed following the guidelines in Bulletin 17B of the U.S. Interagency Advisory Committee on Water Data. To determine the peak-flow exceedance probabilities at stream-gaging stations in Vermont, a new generalized skew coefficient map for the State was developed. This new map has greater resolution and more current data than the existing National map. The standard error of the new map is 0.269. Two methods of extending streamflow record were applied to improve estimates of peak-flow frequency for streams with short flow records (10 to 15 years) in small drainage areas (sites less than 15 square miles). In the first method, a two-station comparison, data from a long-record site was used to adjust the frequency characteristics at the short-record site. This method was applied to 31 crest-stage gages--stations at which only instantaneous peak discharges are determined--in Vermont. The second method used rainfall-runoff modeling. Precipitation and evapotranspiration data from 1948 to 1999 for numerous climate data-collection sites were used as input to a model to simulate flows at 10 stream-gaging stations in Vermont. Also, methods are described to estimate flow-frequency characteristics for ungaged and unregulated rural streams in Vermont. The peak-flow estimating methods were developed by generalized-least-squares regression procedures with data from 138 U.S. Geological Survey stream-gaging stations in Vermont and in adjacent areas of New York, New Hampshire, Massachusetts, and Quebec. The flow-duration (daily flow exceeded a given percentage of the time) estimating methods were developed by ordinary-least-squares regression procedures with data from 81 stream-gaging stations in Vermont and adjacent states.

Vermont↗

USGS2003

Estimating the magnitude of the 100-year peak flow in the Big Lost River at the Idaho National Engineering and Environmental Laboratory, Idaho

Accurate estimates of peak flows in the Big Lost River at the Idaho National Engineering and Environmental Laboratory (INEEL) are needed to assist planners and managers with evaluating possible effects of flooding on facilities at the INEEL. A large difference of 4,350 cubic feet per second (ft 3 /s) between two previous estimates of the magnitude of the 100-year peak flow in the Big Lost River near the western boundary of the INEEL prompted the present study. Regression models that compared annual peak flows and attenuation of annual peak flows between successive gaging stations for the same flow event were used to estimate the magnitude of the 100-year peak flow in the Big Lost River. The 100-year peak flow of 4,790 ft 3 /s at the Howell Ranch gaging station was used as the starting point for this analysis. This estimate was determined by using a three-parameter log-Pearson Type III distribution as outlined in “Guidelines for Determining Flood Flow Frequency” (Bulletin 17B by the Interagency Advisory Committee on Water Data). The regression models indicated that, in the reach of the Big Lost River between Howell Ranch and Mackay Reservoir, downstream peak flows are lower than upstream peak flows. Peak-flow attenuation values for this reach of the river decreased nonlinearly as the magnitude of the peak flow increased. Extrapolation of the trend resulted in an attenuation estimate of 13 percent for this reach relative to the 100-year peak flow at the Howell Ranch gaging station. In the lower reach of the Big Lost River between Mackay Reservoir and Arco, downstream peak flows are also lower than upstream peak flows. However, in contrast to the upper reach, peak-flow attenuation values decreased linearly as the magnitude of the peak flow increased. Extrapolation of the data indicated that peak-flow attenuations in this reach of the river approach zero for flows approaching the 100-year peak-flow estimate immediately upstream and downstream from Mackay Reservoir. A regression model of annual maximum daily mean flows between Arco and the INEEL diversion dam indicated that the attenuation values in this reach of the river are nearly the same for all flows of record. Extrapolation of the linear regression of these values resulted in an attenuation estimate of 10 percent. Seepage measurements made during 1951–53 also resulted in a loss estimate of approximately 10 percent. This attenuation value, combined with the values from analyses of the upstream reaches, resulted in an estimate of the 100-year peak flow for the Big Lost River immediately upstream from the INEEL diversion dam of 3,750 ft 3 /s; upper and lower 95-percent confidence limits were 6,250 ft 3 /s and 1,300 ft 3 /s, respectively. Localized rainfall, even of high intensity, is not likely to produce large peak flows at the INEEL because of high loss rates (infiltration, bank storage, and channel storage) along much of the stream channel. The relatively short flow durations resulting from rainstorms historically have not provided sufficient volumes of water to satisfy local storage demands (bank and channel storage). Only after these storage demands are met do the loss rates decrease enough for significant peak flows to reach the INEEL site. An uncertain component of the present analysis is the effect of seismic activity on the 100-year peak-flow estimate. Analysis of the effect of the magnitude 7.3 Borah Peak earthquake in 1983 on normal flow conditions in the Big Lost River suggests that the joint occurrence of a large earthquake and a 100-year peak flow could significantly increase the magnitude of the peak flow at the INEEL.

Idaho↗

USGS2003

Estimating the magnitude of peak flows for streams in Kentucky for selected recurrence intervals

This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Kentucky for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for a site on a specific stream. Estimates of peak flows are given for 222 U.S. Geological Survey streamflow-gaging stations in Kentucky. In the development of the peak-flow estimates at gaging stations, a new generalized skew coefficient was calculated for the State. This single statewide value of 0.011 (with a standard error of prediction of 0.520) is more appropriate for Kentucky than the national skew isoline map in Bulletin 17B of the Interagency Advisory Committee on Water Data. Regression equations are presented for estimating the peak flows on ungaged, unregulated streams in rural drainage basins. The equations were developed by use of generalized-least-squares regression procedures at 187 U.S. Geological Survey gaging stations in Kentucky and 51 stations in surrounding States. Kentucky was divided into seven flood regions. Total drainage area is used in the final regression equations as the sole explanatory variable, except in Regions 1 and 4 where main-channel slope also was used. The smallest average standard errors of prediction were in Region 3 (from -13.1 to +15.0 percent) and the largest average standard errors of prediction were in Region 5 (from -37.6 to +60.3 percent). One section of this report describes techniques for estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins. Another section references two previous U.S. Geological Survey reports for peak-flow estimates on ungaged, unregulated, urban streams. Estimating peak flows at ungaged sites on regulated streams is beyond the scope of this report, because peak flows on regulated streams are dependent upon variable human activities.

Kentucky↗

USGS1974

Flood characteristics of Oklahoma streams techniques for calculating magnitude and frequency of floods in Oklahoma, with compilations of flood data through 1971

The 2-, 5-, 10-, 25-, 50-, and 100-year recurrence interval floods are related to basin and climatic parameters for natural streams in Oklahoma by multiple regression techniques through the mathematical model, Q x =aA b S c P d , where Q x is peak discharge for recurrence interval x, A is contributing drainage area, S is main channel slope, P is mean annual precipitation, and a, b, c, and d are regression constants and coefficients. One equation for each recurrence interval applies statewide for all natural streams of less than 2,500 mil (6,500 km 2 ), except where manmade works, such as dams, flood-detention structures, levees, channelization, and urban development, appreciably affect flood runoff. The equations can be used to estimate flood frequency of a stream at an ungaged site if drainage area size, main channel slope, and mean annual precipitation are known. At or near gaged sites, a weighted average of the regression results and the gaging station data is recommended. Individual relations of flood magnitude to contributing drainage area are given for all or parts of the main stems of the Arkansas, Salt Fork Arkansas, Cimarron, North Canadian, Canadian, Washita, North Fork Red, and Red Rivers. Parts of some of these streams, and all of the Neosho and Verdigris Rivers are not included because the effects of. major regulation from large reservoirs cannot be evaluated within the scope of the report. Graphical relations of maximum floods of record for eastern and western Oklahoma provide a guide to maximum probable floods. A random sampling of the seasonal occurrence of floods indicated about two-thirds of all annual floods in Oklahoma occur during. April through July. Less than one-half of one percent of annual floods occur in December. A compilation of flood records at all gaging sites in Oklahoma and some selected sites in adjacent States is given in an appendix. Basin and climatic parameters and log-Pearson Type III frequency data and statistics are given for most station records. A second appendix gives a reprint of the U.S. Water Resources Council Bulletin 15 which describes procedures for fitting a log-Pearson Type III distribution to gaging station data.

Oklahoma↗

USGS1987

Floods in Kansas and techniques for estimating their magnitude and frequency on unregulated streams

Techniques are presented for generalizing the skewness coefficient of log-Pearson Type III distributions of annual maximum discharges and for flood magnitudes that have selected recurrence intervals from 2 to 100 yr. A weighted least-square (WLS) regression model was used to generalize the coefficients of station skewness that resulted in a root-mean-sq error of prediction of 0.35 compared to 0.55 for the skewness map published in Bulletin 17B of the U.S. Water Resources Council. Estimates of generalized skewness were computed for each of 245 streamflow gaging stations with a minimum of 10 years of record and a contributing drainage area of < 20,000 sq mi. The WLS regression model also was used to develop equations for estimating flood magnitude for selected recurrence intervals for ungaged stream locations by using data from 218 of the 245 streamflow gaging stations that had contributing-drainage areas of less than 10,000 sq mi. The errors of prediction of the most reliable WLS equations ranged from 28 to 42%. The WLS equations were compared statistically to previous developed equations and were determined to be different and more accurate than previously published equations. Flood magnitudes and frequencies for 245 streamflow gaging stations, based on data collected through the 1983 water year, are presented along with a summary of the seasonal distribution of annual maximum discharges and an analysis of the maximum observed discharges. (Author 's abstract)

Water-Resources Investigations Report↗

USGS1999

Estimating the magnitude of peak flows for streams in Maine for selected recurrence intervals

This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Maine for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for a site on a specific stream. Section 1, 'Estimates of peak flows and maximum recorded flows at USGS streamflow-gaging stations,' contains peak-flow estimates and the maximum recorded flows at 98 U.S. Geological Survey (USGS) streamflow-gaging stations. In the development of the peak-flow estimates at gaging stations, a new generalized skew coefficient was calculated for Maine. This single statewide value of 0.029 (with a standard error of prediction of 0.297) is more accurate for Maine than the national skew isoline map in Bulletin 17B of the Interagency Advisory Committee on Water Data. Two techniques are presented to estimate the peak flows for ungaged, unregulated streams in rural drainage basins. These two techniques were developed using generalized least squares regression procedures at 70 USGS gaging stations in Maine and eastern New Hampshire. Section 2, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins,' uses the final explanatory variables of drainage area and basin wetlands. The average standard error of prediction for the 100-year peak flow regression equation in section 2 was 48.6 percent to -32.7 percent. Drainage area was the only explanatory variable used in section 3, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins - Simplified technique.' The average standard error of prediction for the 100-year peak flow regression equation in section 3 was 80.3 percent to -44.5 percent. Section 4 of the report describes techniques for estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins. Section 5, 'Estimating peak flows for ungaged, unregulated streams in urbanized drainage basins,' describes regression equations for use when a drainage basin is urbanized. These urban regression equations come from a previous USGS nationwide study. As stated in section 6, because peak flows on regulated streams are dependent on variable human actions, estimating peak flows at ungaged sites on regulated streams is beyond the scope of this report.

Maine↗

USGS1999

Peak-flow frequency relations and evaluation of the peak-flow gaging network in Nebraska

Estimates of peak-flow magnitude and frequency are required for the efficient design of structures that convey flood flows or occupy floodways, such as bridges, culverts, and roads. The U.S. Geological Survey, in cooperation with the Nebraska Department of Roads, conducted a study to update peak-flow frequency analyses for selected streamflow-gaging stations, develop a new set of peak-flow frequency relations for ungaged streams, and evaluate the peak-flow gaging-station network for Nebraska. Data from stations located in or within about 50 miles of Nebraska were analyzed using guidelines of the Interagency Advisory Committee on Water Data in Bulletin 17B. New generalized skew relations were developed for use in frequency analyses of unregulated streams. Thirty-three drainage-basin characteristics related to morphology, soils, and precipitation were quantified using a geographic information system, related computer programs, and digital spatial data.For unregulated streams, eight sets of regional regression equations relating drainage-basin to peak-flow characteristics were developed for seven regions of the state using a generalized least squares procedure. Two sets of regional peak-flow frequency equations were developed for basins with average soil permeability greater than 4 inches per hour, and six sets of equations were developed for specific geographic areas, usually based on drainage-basin boundaries. Standard errors of estimate for the 100-year frequency equations (1percent probability) ranged from 12.1 to 63.8 percent. For regulated reaches of nine streams, graphs of peak flow for standard frequencies and distance upstream of the mouth were estimated.The regional networks of streamflow-gaging stations on unregulated streams were analyzed to evaluate how additional data might affect the average sampling errors of the newly developed peak-flow equations for the 100-year frequency occurrence. Results indicated that data from new stations, rather than more data from existing stations, probably would produce the greatest reduction in average sampling errors of the equations.

Nebraska↗

USGS1983

Estimating peak discharges of small, rural streams in Massachusetts

Floodflows on natural-flow streams in Massachusetts with drainage areas between 0.25 square miles and 260 square miles may be estimated from drainage area, main-channel slope, mean basin elevation, and the area of swamps, lakes, and ponds. Multiple-regression techniques were used to define the relationship between a suite of basin and climatic characteristics and flood peaks in three flood-frequency regions at a total of 95 sites. Station flood-frequency data were computed following guidelines in Bulletin 17A of the U.S. Water Resources Council. The frequency analyses are based upon weighted skew values, adjustments for high and low outliers, and historic peak data. Regression equations for estimation of peak discharges for 0.5, 0.2, 0.1, 0.04, 0.02, and 0.01 exceedance probabilities are provided for ungaged sites. An improved sample of flood peaks and gaging stations and the definition of three flood-frequency regions reduced the standard errors of estimate by about 5 percent over those for the 1977 relations. Included in this analysis were the synthetic flood-frequency data at 8 sites computed using historic climatic data and 10 parameters optimized by calibration of the U.S. Geological Survey's rainfall-runoff model with storm data observed over 11 years. The equations are applicable to streams unaffected by regulation where the usable manmade storage is less than 4.5 million cubic feet per square mile, or by diversions or urbanization. The equations are restricted to sites where the basin indices are within a specified range outside of eastern Plymouth, Barnstable, Dukes, or Nantucket Counties. In these areas, the available data do not adequately define the influence of high infiltration and storage capacities of drainage basins on floodflows.

Water Supply Paper↗

USGS1915

Stream-gaging stations and publications relating to water sources, 1885-1913; Part IX: Colorado River basin

Investigation of water resources by the United States Geological Survey has consisted in large part of measurements of the volume of flow of streams and studies of the conditions affecting that flow, but it has comprised also investigation of such closely allied subjects as irrigation, water storage, water powers, underground waters, and quality of waters. Most of the results of these investigations have been published in the series of water-supply papers, but some have appeared in the monographs, bulletins, professional papers, and annual reports.

Colorado River basin↗

USGS1915

Stream-gaging stations and publications relating to water sources, 1885-1913; Part X: The Great Basin

Investigation of water resources by the United States Geological Survey has consisted in large part of measurements of the volume of fl.ow of streams and studies of the conditions affecting that flow, but it has comprised also investigation of such closely allied subjects as irrigation, water storage, water powers, underground waters, and quality of waters. Most of the results of these investigations have been published in the series of water-supply papers, but some have appeared in the bulletins, professional papers, and annual reports.

Great Basin↗