A streamflow data set, which is specifically suitable for the study of surface-water conditions throughout the United States under fluctuations in the prevailing climatic conditions, has been developed. This data set, called the Hydro-Climatic Data Network, or HCDN, consists of streamflow records for 1,659 sites throughout United States and its Territories.

This data release identifies 555 Hydro-Climatic Data Network (HCDN) streamgages in the conterminous United States during the period 1981-2019 which were grouped according to similarity in their temporal patterns of mean monthly streamflow.

The Hydro-Climatic Data Network (HCDN) Streamflow Data CD-ROM contains historical streamflow data that are specifically suitable for the study of surface-water conditions throughout the United States and its territories. The dates of the data range between 1874 and 1988. Cite this CD-ROM as follows: Slack, J. R., A. Lumb, and J. M. Landwehr. 1993. Hydro-Climatic Data Network (HCDN) Streamflow Data Set, 1874-1998. CD-ROM. U.S. Geological Survey, Reston, Virginia, U.S.A. Available from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. [http://www.daac.ornl.gov].

Time series of monthly minimum and maximum temperature, precipitation, and potential evapotranspiration were derived for 1,469 watersheds in the conterminous United States for which stream flow measurements were also available from the national streamflow database, termed the Hydro-Climatic Data Network (HCDN), developed by Slack et al. (1993a,b). Monthly climate estimates were derived for the years 1951-1990.The climate characteristic estimates of temperature and precipitation were estimated using the PRISM (Daly et al. 1994, 1997) climate analysis system as described in Vogel, et al. 1999.Estimates of monthly potential evaporation were obtained using a method introduced by Hargreaves and Samani (1982) which is based on monthly time series of average minimum and maximum temperature data along with extraterrestrial solar radiation. Extraterrestrial solar radiation was estimated for each basin by computing the solar radiation over 0.1 degree grids using the method introduced by Duffie and Beckman (1980) and then summing those estimates for each river basin. This process is described in Sankarasubramanian, et al. (2001). Revision Notes: This data set has been revised to update the number of watersheds included in the data set and to updated the units for the potential evapotranspiration variable. Please see the Data Set Revisions section of this document for detailed information.

Time series of monthly minimum and maximum temperature, precipitation and potential evapotranspiration were derived for 1337 watersheds in the conterminous United States for sites found in the national streamflow database, termed the hydroclimatologic data network (HCDN), developed by Slack et al. (1993a,b). Estimates were derived for the years 1951-1990.This HCDN data set consists of records of average daily streamflow at 1553 sites located throughout the United States. The data meet certain measurement accuracy criterion outlined by Slack et al. (1993). The HCDN contains river flows from 1874 to 1988, with an average record length of 44 years. The streamflow data included in the HCDN is purported to be relatively free from anthropogenic influences and the accuracy ratings of these records are at least rated good per USGS standards. A subset of the HCDN streamflow sites from 1337 watersheds with at least 10 years of record length was used. This subset includes 1376 HCDN sites.The climate characteristic estimates of temperature and precipitation were estimated using the PRISM (Daly et al. 1994, 1997) climate analysis system as described in Vogel, et al. 1999.Estimates of monthly potential evaporation were obtained using a method introduced by Hargreaves and Samani (1982) which is based on monthly time series of average minimum and maximum temperature data along with extraterrestrial solar radiation. Extraterrestrial solar radiation was estimated for each HCDN basin by computing the solar radiation over 0.1 degree grids using the method introduced by Duffie and Beckman (1980) and then summing those estimates for each river basin. This process is described in Sankarasubramanian, Vogel, and Limbrunner, 2001.The data files are organized in directories by parameter, Tmax, Tmin, Pre, and PET, and contain 18 subdirectories representing the 18 HCDN regions. Each region subdirectory contains data files for the monthly time series of respective hydroclimate attributes (Tmax, Tmin, Precipitation, and PET) for the individual HCDN sites in that region for the years 1951-1990. All files are in space delimited ASCII format.

This Resource serves to explain and contain the methodology and results of the United States Geological Survey (USGS) Hydro-Climatic Data Network 2009 (HCDN-2009) freshwater supply key indicator analysis for my thesis. For more information, see my thesis at the USU Digital Commons.

Freshwater availability in the state can be summarized using streamflow, reservoir level, precipitation, and temperature data. Climate data for this study have a period of record greater than 30 years, preferably extending beyond 1950, and are representative of natural conditions at the county-level.

A limited number of USGS HCDN-2009 streamflow gages were found that can represent statewide conditions, are unimpaired (which produces natural hydrographs), and have measurements that extend as far back as water year 1915, making them suitable for this study. USGS HCDN-2009 streamgage data for Utah are available and downloaded as tab-separated files from the USGS National Water Information System: Web Interface. To relate HCDN-2009 streamflow measurements as water supply indicators to every five-year annual USGS irrigation withdrawal and acreage data, they were summarized at water year timesteps. Annual summations of each daily average cubic feet per second measurement over each water year (1 OCT – 30 SEP) were calculated. This gives an annual volume of streamflow at each gage for each available water year. For the known periods of time when there were measurement malfunctions, USGS models and approves data to fill these gaps.

Freshwater availability key indicators were non-parametrically separated per temporal/spatial delineation into quintiles representing Very Wet/Very High/Hot (top 20% of values), Wet/High/Hot (60-80%), Moderate/Mid-level (40-60%), Dry/Low/Cool (20-40%), to Very Dry/Very Low/Cool (bottom 20%). Each quintile bin was assigned a rank value 1-5, with ‘5’ being the value of the top quintile, in preparation for the Kendall Tau-b correlation analysis. These results, along with USGS irrigation withdrawal and acreage data, were loaded into R. State-level quintile results were matched according to USGS report year. County quintile results were matched with corresponding USGS irrigation withdrawal and acreage county-level data per report year for all other areas of interest.

See Word file for an Example PRISM Analysis, made by Alan Butler at the United States Bureau of Reclamation, which was used as a guide for this analysis.

This dataset, termed "GAGES II", an acronym for Geospatial Attributes of Gages for Evaluating Streamflow, version II, provides geospatial data and classifications for 9,322 stream gages maintained by the U.S. Geological Survey (USGS). It is an update to the original GAGES, which was published as a Data Paper on the journal Ecology's website (Falcone and others, 2010b) in 2010. The GAGES II dataset consists of gages which have had either 20+ complete years (not necessarily continuous) of discharge record since 1950, or are currently active, as of water year 2009, and whose watersheds lie within the United States, including Alaska, Hawaii, and Puerto Rico. Reference gages were identified based on indicators that they were the least-disturbed watersheds within the framework of broad regions, based on 12 major ecoregions across the United States. Of the 9,322 total sites, 2,057 are classified as reference, and 7,265 as non-reference. Of the 2,057 reference sites, 1,633 have (through 2009) 20+ years of record since 1950. Some sites have very long flow records: a number of gages have been in continuous service since 1900 (at least), and have 110 years of complete record (1900-2009) to date. The geospatial data include several hundred watershed characteristics compiled from national data sources, including environmental features (e.g. climate – including historical precipitation, geology, soils, topography) and anthropogenic influences (e.g. land use, road density, presence of dams, canals, or power plants). The dataset also includes comments from local USGS Water Science Centers, based on Annual Data Reports, pertinent to hydrologic modifications and influences. The data posted also include watershed boundaries in GIS format. This overall dataset is different in nature to the USGS Hydro-Climatic Data Network (HCDN; Slack and Landwehr 1992), whose data evaluation ended with water year 1988. The HCDN identifies stream gages which at some point in their history had periods which represented natural flow, and the years in which those natural flows occurred were identified (i.e. not all HCDN sites were in reference condition even in 1988, for example, 02353500). The HCDN remains a valuable indication of historic natural streamflow data. However, the goal of this dataset was to identify watersheds which currently have near-natural flow conditions, and the 2,057 reference sites identified here were derived independently of the HCDN. A subset, however, noted in the BasinID worksheet as “HCDN-2009”, has been identified as an updated list of 743 sites for potential hydro-climatic study. The HCDN-2009 sites fulfill all of the following criteria: (a) have 20 years of complete and continuous flow record in the last 20 years (water years 1990-2009), and were thus also currently active as of 2009, (b) are identified as being in current reference condition according to the GAGES-II classification, (c) have less than 5 percent imperviousness as measured from the NLCD 2006, and (d) were not eliminated by a review from participating state Water Science Center evaluators. The data posted here consist of the following items:- This point shapefile, with summary data for the 9,322 gages.- A zip file containing basin characteristics, variable definitions, and a more detailed report.- A zip file containing shapefiles of basin boundaries, organized by classification and aggregated ecoregion.- A zip file containing mainstem stream lines (Arc line coverages) for each gage.

Time series of monthly minimum and maximum temperature, precipitation, and potential evapotranspiration were derived for 1,469 watersheds in the conterminous United States for which stream flow measurements were also available from the national streamflow database, termed the Hydro-Climatic Data Network (HCDN), developed by Slack et al. (1993a,b). Monthly climate estimates were derived for the years 1951-1990.The climate characteristic estimates of temperature and precipitation were estimated using the PRISM (Daly et al. 1994, 1997) climate analysis system as described in Vogel, et al. 1999.Estimates of monthly potential evaporation were obtained using a method introduced by Hargreaves and Samani (1982) which is based on monthly time series of average minimum and maximum temperature data along with extraterrestrial solar radiation. Extraterrestrial solar radiation was estimated for each basin by computing the solar radiation over 0.1 degree grids using the method introduced by Duffie and Beckman (1980) and then summing those estimates for each river basin. This process is described in Sankarasubramanian, et al. (2001). Revision Notes: This data set has been revised to update the number of watersheds included in the data set and to updated the units for the potential evapotranspiration variable. Please see the Data Set Revisions section of this document for detailed information.

This dataset contains annual peak and seasonal maximum streamflow data from the USGS National Water Information System (NWIS) and the results of an analysis of spatial and temporal patterns for those data for the conterminous U.S. An interpretation of the analysis of these data will be published in a journal article. The streamflow data were compiled for the years 1966 to 2015 for 415 streamgages that are part of the USGS HCDN-2009 network. The HCDN-2009 network contains streamgages in watersheds with minimal anthropogenic change. The dataset contains the annual peak and the maximum daily streamflow for the months of October through December (OND), January through March (JFM), April through June (AMJ), and July through September (JAS). The maximum daily streamflow for OND, JFM, AMJ, and JAS was determined as the largest daily streamflow over those months. This dataset contains the following files for the annual peaks and maximum daily streamflow. The files labeled "raw" contain the water year and the raw annual peaks from NWIS and the selected maximum daily streamflow from NWIS. The files labeled "SPI" contain the water year and the standardized peaks and maximum daily streamflow by using the Standardized Precipitation Index method. The files labeled "cluster_assignments" contain (in columns) the gage name (two letter abbreviation of the state in which the gage is located and the USGS site number), the latitude and longitude (NAD 83) of the gage, an integer that is an identifier of the cluster that the gage was assigned, and the Pearson correlation coefficient between the standardized streamflow and the average standardized streamflow of all gages in its cluster. The annual peaks were clustered into 4 groups, the OND maximum flows were clustered into 7 groups, the JFM maximum flows were clustered into 9 groups, and the both the AMJ and JAS maximum flows were clustered into 5 groups. The files with the term "cluster_means" in the file name contain the water year and the mean of the standardized streamflow of all gages in the clusters of peaks and maximum daily streamflow for OND, JFM, AMJ, and JAS.

These data describe the 10-largest annual, instantaneous flood peaks and corresponding dates of those largest floods for 473 streamgages in the Hydro-Climatic Data Network (HCDN) HCDN-2009 (Lins, 2012) network; they are also the data and results used in the companion manuscript by Collins, M.J, Hodgkins, G.A., Archfield, S.A., and Hirsch, R.M, under review, "The occurrence of large floods in the United States in the modern hydroclimate regime: seasonality, trends, and large-scale climate associations," and submitted to Water Resources Research. The HCDN-2009 (Lins, 2012) network is a subset of streamgages classified as unimpaired to the extent possible that any upstream regulation or urbanization could be evaluated. From this network, the set of streamgages was further narrowed based on their completeness of record and according to the criteria used in Hodgkins et al. (2019) and Dudley et al (2018), which requires that each decade of annual flood peaks have at least 8 observations ...

This data release contains trend results computed on the basis of modeled and observed daily streamflows at 502 reference gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-Correlation Drainage Area Ratio (MCDAR), Ordinary Kriging of the logarithms of discharge per unit area (OKDAR), Nearest-Neighbor nonlinear spatial interpolation using flow duration curves (NNQPPQ), and Map-Correlation nonlinear spatial interpolation using flow duration curves (MCQPPQ). Observed daily streamflow data for the study gages were retrieved from the National Water Information System (NWIS). Study gages were selected from among Hydro-Climatic Data Network 2009 (HCDN-2009) gages in the GAGES-II dataset considered to be minimally affected by regulation, diversion, mining, or other anthropogenic activities. Results include trends in annual and monthly means, annual percentiles (1, 5, 10, 25, 50, 75, 90, 95, 99), annual 1-day high, 3-day high, and 7-day low, and annual snowmelt-related runoff timing for a subset of snowmelt dominated basins. Bias and volumetric efficiency statistics between observed and modeled streamflows also are provided.

The hydrometeorological time series together with the catchment attributes constitute the CAMELS dataset: Catchment Attributes and MEteorology for Large-sample Studies. TIME SERIES Data citation: A. Newman; K. Sampson; M. P. Clark; A. Bock; R. J. Viger; D. Blodgett, 2014. A large-sample watershed-scale hydrometeorological dataset for the contiguous USA. Boulder, CO: UCAR/NCAR. https://dx.doi.org/10.5065/D6MW2F4D Associated paper: A. J. Newman, M. P. Clark, K. Sampson, A. Wood, L. E. Hay, A. Bock, R. J. Viger, D. Blodgett, L. Brekke, J. R. Arnold, T. Hopson, and Q. Duan: Development of a large-sample watershed-scale hydrometeorological dataset for the contiguous USA: dataset characteristics and assessment of regional variability in hydrologic model performance. Hydrol. Earth Syst. Sci., 19, 209-223, doi:10.5194/hess-19-209-2015, 2015. We developed basin scale hydrometeorological forcing data for 671 basins in the United States Geological Surveyâ s Hydro-Climatic Data Network 2009 (HCDN-2009, Lins 2012) conterminous U.S. basin subset. Retrospective model forcings are derived from Daymet, NLDAS, and Maurer et al. (2002) Daymet and NLDAS forcing data run from 1 Jan 1980 to 31 Dec 2014, and Maurer run from 1 January 1980 to 31 December 2008. Model timeseries output is available for the same time periods as the forcing data. USGS streamflow data are also provided for all basins for all dates available in the 1 Jan to 31 Dec 2014 period. We then implemented the hydrologic model and calibration routine traditionally used by the NWS, the SNOW-17 and Sacramento soil moisture accounting (SAC-SMA) based hydrologic modeling system and the shuffled complex evolution (SCE) optimization approach (Duan et al. 1993). To retrieve the entire time series dataset, all five .zip files should be downloaded. The basin_timeseries_v1p2_metForcing_obsFlow.zip file contains all the basin forcing data for all three meteorology products, observed streamflow, basin metadata, readme files, and...

This data release contains trend results computed on the basis of modeled and observed daily streamflows at 502 reference gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-Correlation Drainage Area Ratio (MCDAR), Ordinary Kriging of the logarithms of discharge per unit area (OKDAR), Nearest-Neighbor nonlinear spatial interpolation using flow duration curves (NNQPPQ), and Map-Correlation nonlinear spatial interpolation using flow duration curves (MCQPPQ). Observed daily streamflow data for the study gages were retrieved from the National Water Information System (NWIS). Study gages were selected from among Hydro-Climatic Data Network 2009 (HCDN-2009) gages in the GAGES-II dataset considered to be minimally affected by regulation, diversion, mining, or other anthropogenic activities. Results include trends in annual and monthly means, annual percentiles (1, 5, 10, 25, 50, 75, 90, 95, 99), annual 1-day high, 3-day high, and 7-day low, and annual snowmelt-related runoff timing for a subset of snowmelt dominated basins. Bias and volumetric efficiency statistics between observed and modeled streamflows also are provided.

Current members of the Argentine Chamber of Deputies, the lower house of the National Congress