This folder contains streamflow timeseries in cubic meters per second for each trace time series at each of the 26 site locations. In column A, there is a row number, column B contains “flow” and is streamflow in cubic meters per second, column C is the month that the streamflow occurs in the stochastic streamflow time series, column D is the year in a given stochastic time series, and column E is “simnum” which is the simulation number. The streamflow is ordered for each year in a timeseries and have 3 streamflow values for each month. The 3 streamflow for each month refer to the first, second, and third 10-day period in a month regardless of whether the month does or does not contain 30-days.

There are 100 traces in the simulation. This metadata file is only associated with the first trace (Trace_1). This directory contains a folder for each of the 100 streamflow time series and are identified as Trace_1, Trace_2, and so on. Within each trace file is a 100-year long time series of streamflow, in cubic meters per second, for each of the 26 sites. In column A, there is a row number, column B is the date of the stochastic streamflow occurrence, column C is a time assignment required for HEC-ResSim to run, and column D contains “Streamflow_cms” and is streamflow in cubic meters per second.

There are 100 traces in the simulation. This metadata file is only associated with the first trace (Trace_1). This directory contains a folder for each of the 100 streamflow time series and are identified as Trace_1, Trace_2, and so on. Within each trace file is a 100-year long time series of streamflow, in cubic meters per second, for each of the 26 sites. In column A, there is a row number, column B is the date of the stochastic streamflow occurrence, column C is a time assignment required for HEC-ResSim to run, and column D contains “Streamflow_cms” and is streamflow in cubic meters per second.

i. .\File_Mapping.csv: This file relates historical reconstructed hydrology streamflow from the U.S. Army Corps of Engineers () to the appropriate stochastic streamflow file for disaggregation of streamflow. Column A is an assigned ID, column B is named “Stochastic” and is the stochastic streamflow file needed for disaggregation, column c is called “RH_Ratio_Col” and is the name of the column in the reconstructed hydrology dataset associated with a stochastic streamflow file, and column D is named “Col_Num” and is the column number in the reconstructed hydrology dataset with the name given in column C. ii. .\Original_Draw_YearDat.csv: This file contains the historical year from 1930 to 2017 with the closest total streamflow for the Souris River Basin to each year in the stochastic streamflow dataset. Column A is an index number, column B is named “V1” and is the year in a simulation, column C is called “V2” and is the stochastic simulation number, column D is an integer that can be related to historical years by adding 1929, and column D is named “year” and is the historical year with the closest total Souris River Basin streamflow volume to the associated year in the stochastic traces. iii. .\revdrawyr.csv: This file is setup the same way that .\Original_Draw_YearDat.csv was except that, when a year had over 400 occurrences, it was randomly replaced with one of the 20 other closest years. The replacement process was completed until there were less than 400 occurrences of each reconstructed hydrology year associated with stochastic simulation years. Column A is an index number, column B is named “V1” and is the year in a simulation, column C is called “V2” and is the stochastic simulation number, column D is called “V3” and is the historical year who’s streamflow ratios will be multiplied by stochastic streamflow, and column E is called “Stoch_yr” and is the total of 2999 and the year in column B. iv. .\RH_1930_2017.csv: This file contains the daily streamflow from the U.S. Army Corps of Engineers (2020), reconstructed hydrology for the Souris River Basin for the period of 1930 to 2017. Column A is the date and columns B through AA are the daily streamflow in cubic feet per second. v. .\rhmoflow_1930Present.csv: This file was created based on .\RH_1930_2017.csv and provides streamflow for each site in cubic meters for a given month. Column A is an unnamed index column, column B is historical year, column C is the historical month associated with the historical year, column D provides a day equal to 1 but does not have particular significance and columns E through AD are monthly streamflow volume for each site location. vi. .\Stoch_Annual_TotVol_CubicDecameters.csv: This file contains the total volume of streamflow for each of the 26 sites for each month in the stochastic streamflow time timeseries and provides a total streamflow volume divided by 100,000 on a monthly basis for the entire Souris River Basin. Column A is unnamed and contains an index number, column B is month and is named “V1”, column C is the year in a simulation, column D is the simulation number, columns E (V4 through V29) through AD are streamflow volume in cubic meters, and column AE (V30) is total Souris River Basin monthly streamflow volume in cubic decameters/1,000.

i. .\File_Mapping.csv: This file relates historical reconstructed hydrology streamflow from the U.S. Army Corps of Engineers () to the appropriate stochastic streamflow file for disaggregation of streamflow. Column A is an assigned ID, column B is named “Stochastic” and is the stochastic streamflow file needed for disaggregation, column c is called “RH_Ratio_Col” and is the name of the column in the reconstructed hydrology dataset associated with a stochastic streamflow file, and column D is named “Col_Num” and is the column number in the reconstructed hydrology dataset with the name given in column C. ii. .\Original_Draw_YearDat.csv: This file contains the historical year from 1930 to 2017 with the closest total streamflow for the Souris River Basin to each year in the stochastic streamflow dataset. Column A is an index number, column B is named “V1” and is the year in a simulation, column C is called “V2” and is the stochastic simulation number, column D is an integer that can be related to historical years by adding 1929, and column D is named “year” and is the historical year with the closest total Souris River Basin streamflow volume to the associated year in the stochastic traces. iii. .\revdrawyr.csv: This file is setup the same way that .\Original_Draw_YearDat.csv was except that, when a year had over 400 occurrences, it was randomly replaced with one of the 20 other closest years. The replacement process was completed until there were less than 400 occurrences of each reconstructed hydrology year associated with stochastic simulation years. Column A is an index number, column B is named “V1” and is the year in a simulation, column C is called “V2” and is the stochastic simulation number, column D is called “V3” and is the historical year who’s streamflow ratios will be multiplied by stochastic streamflow, and column E is called “Stoch_yr” and is the total of 2999 and the year in column B. iv. .\RH_1930_2017.csv: This file contains the daily streamflow from the U.S. Army Corps of Engineers (2020), reconstructed hydrology for the Souris River Basin for the period of 1930 to 2017. Column A is the date and columns B through AA are the daily streamflow in cubic feet per second. v. .\rhmoflow_1930Present.csv: This file was created based on .\RH_1930_2017.csv and provides streamflow for each site in cubic meters for a given month. Column A is an unnamed index column, column B is historical year, column C is the historical month associated with the historical year, column D provides a day equal to 1 but does not have particular significance and columns E through AD are monthly streamflow volume for each site location. vi. .\Stoch_Annual_TotVol_CubicDecameters.csv: This file contains the total volume of streamflow for each of the 26 sites for each month in the stochastic streamflow time timeseries and provides a total streamflow volume divided by 100,000 on a monthly basis for the entire Souris River Basin. Column A is unnamed and contains an index number, column B is month and is named “V1”, column C is the year in a simulation, column D is the simulation number, columns E (V4 through V29) through AD are streamflow volume in cubic meters, and column AE (V30) is total Souris River Basin monthly streamflow volume in cubic decameters/1,000.

.\Spring 30 day\ I. .\GrantDevine_Comb.csv: This file contains the total inflow volume to Grant Devine Reservoir for the 30 days with the largest streamflow volume between March and May and the mean of the 3- and 12-month SPEI values for each November 1st. Spring streamflow volume for a given calendar year is paired with SPEI from the previous November 1st value. Column A is an unnamed index number, column B is a year in a stochastic simulation, column C is named “simnum” and is the stochastic simulation number, column D is named “mnspei” and is the mean of the 3- and 12-month SPEI for November 1 of each year in a stochastic simulation, and column E is named “SprintgThirtyTot” and is the total inflow volume for the 30 days with the largest streamflow volume between March and May of the following calendar year. II. .\LakeDarling_Comb.csv: has the same layout as .\GrantDevine_Comb.csv except that it is for local inflows to Lake Darling. III. .\Rafferty_Comb.csv: has the same layout as .\GrantDevine_Comb.csv except that it is for local inflows to Rafferty.

In 2016, non-interpretive streamflow statistics were compiled for streamgages located throughout the Nation and stored in the StreamStatsDB database for use with StreamStats and other applications. Two previously published USGS computer programs that were designed to help calculate streamflow statistics were updated to better support StreamStats as part of this effort. These programs are named “GNWISQ” (Get National Water Information System Streamflow (Q) files) and “QSTATS” (Streamflow (Q) Statistics). Statistics for 20,438 streamgages that had 1 or more complete years of record during water years 1901 through 2015 were calculated from daily mean streamflow data; 19,415 of these streamgages were within the conterminous United States. About 89 percent of the 20,438 streamgages had 3 or more years of record, and 65 percent had 10 or more years of record. Drainage areas of the 20,438 streamgages ranged from 0.01 to 1,144,500 square miles. The magnitude of annual average streamflow yields (streamflow per square mile) for these streamgages varied by almost six orders of magnitude, from 0.000029 to 34 cubic feet per second per square mile. About 64 percent of these streamgages did not have any zero-flow days during their available period of record. The 18,122 streamgages with 3 or more years of record were included in the StreamStatsDB compilation so they would be available via the StreamStats interface for user-selected streamgages.

This data release contains values of 29 streamflow statistics computed from modeled and observed daily streamflows from October 1, 1983, through September 30, 2016 at 1,257 streamgages in the 19 study regions defined by Falcone (2011) covering the conterminous United States. The streamflow statistics were computed at GAGES-II non-reference streamgages (Falcone, 2011), determined to be affected by only irrigation or regulation among antrhopogenic influences. At each streamgage, statistics were computed from daily streamflow observations, from daily streamflow time series computed using the National Hydrologic Model-Precipitation Runoff Modeling System (NHM-PRMS) model (the “by headwater” and "by observation" calibrations with Muskingum routing; Hay and LaFontaine, 2020), and from daily streamflow time series computed using five statistical time series models fitted to reference basins (Russell and others, 2021). The data release comprises nine .csv files. The streamflow statistics values are provided in eight of these files, one each for the observed, the two NHM-PRMS calibrations, and the five statistical time series models. The remaining file is a summary table, which provides period-of-record information for each streamgage. References cited: Falcone, J.A., 2011, GAGES-II: Geospatial Attributes of Gages for Evaluating Streamflow [digital spatial dataset]: U.S. Geological Survey Water Resources NSDI Node web page, https://water.usgs.gov/lookup/getspatial?gagesII_Sept2011. Hay, L.E., and LaFontaine, J.H., 2020, Application of the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS), 1980-2016, Daymet Version 3 calibration: U.S. Geological Survey data release, https://doi.org/10.5066/P9PGZE0S. Russell, A.M., Over, T.M., Farmer, W.H., and Miles, K.J., 2021, Statistical daily streamflow estimates at GAGES-II non-reference streamgages in the conterminous Unites States, Water Years 1981-2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9PA9PKM.

.\Stochastic Meteorology\ I. .\genpet.csv: This file contains stochastic monthly PET values for each weather station used to develop stochastic climate data in Kolars and others (2016). Column A is the weather station number, column B is the year in a stochastic simulation, column’s C through N are January through December PET values in millimeters, respectively. Simulations are stacked in order from 1 to 100 for each weather station. II. .\genprec.csv: This file contains stochastic monthly precipitation values for each weather station used to develop stochastic climate data in Kolars and others (2016). Column A is the weather station number, column B is the year in a stochastic simulation, column’s C through N are January through December precipitation values in millimeters, respectively. Simulations are stacked in order from 1 to 100 for each weather station. III. .\ grid_pet_stoch.csv: This file provides monthly stochastic PET values for each grid point used in the WBM presented in Kolars and others (2016). Column A is an unnamed index, column B, “lat”, is the latitude for a grid point, column C, “lon”, is the longitude for a grid point, column D is the year in a stochastic simulation, and columns E through P are the values of PET for January through December in millimeters, respectively. Simulations are ordered and placed on top of one another. IV. .\ grid_prec_stoch.csv: This file provides monthly stochastic precipitation values for each grid point used in the WBM presented in Kolars and others (2016). Column A is an unnamed index, column B, “lat”, is the latitude for a grid point, column C, “lon”, is the longitude for a grid point, column D is the year in a stochastic simulation, and columns E through P are the values of precipitation for January through December in millimeters, respectively. Simulations are ordered and placed on top of one another. V. .\PETMM_basinAv_stoch.csv: This file contains the Souris River Basin average PET for each month of the stochastic PET time series. Column A is an unnamed index, column B, “simnum” is the simulation number, column C, “yr”, is the year in a stochastic simulation, and columns D through O are the PET values in millimeters for January through December, respectively. VI. .\PrecipMM_basinAv_stoch.csv: This file contains the Souris River Basin average precipitation for each month of the stochastic precipitation time series. Column A is an unnamed index, column B, “simnum” is the simulation number, column C, “yr”, is the year in a stochastic simulation, and columns D through O are the precipitation values in millimeters for January through December, respectively.

.\Stochastic Meteorology\ I. .\genpet.csv: This file contains stochastic monthly PET values for each weather station used to develop stochastic climate data in Kolars and others (2016). Column A is the weather station number, column B is the year in a stochastic simulation, column’s C through N are January through December PET values in millimeters, respectively. Simulations are stacked in order from 1 to 100 for each weather station. II. .\genprec.csv: This file contains stochastic monthly precipitation values for each weather station used to develop stochastic climate data in Kolars and others (2016). Column A is the weather station number, column B is the year in a stochastic simulation, column’s C through N are January through December precipitation values in millimeters, respectively. Simulations are stacked in order from 1 to 100 for each weather station. III. .\ grid_pet_stoch.csv: This file provides monthly stochastic PET values for each grid point used in the WBM presented in Kolars and others (2016). Column A is an unnamed index, column B, “lat”, is the latitude for a grid point, column C, “lon”, is the longitude for a grid point, column D is the year in a stochastic simulation, and columns E through P are the values of PET for January through December in millimeters, respectively. Simulations are ordered and placed on top of one another. IV. .\ grid_prec_stoch.csv: This file provides monthly stochastic precipitation values for each grid point used in the WBM presented in Kolars and others (2016). Column A is an unnamed index, column B, “lat”, is the latitude for a grid point, column C, “lon”, is the longitude for a grid point, column D is the year in a stochastic simulation, and columns E through P are the values of precipitation for January through December in millimeters, respectively. Simulations are ordered and placed on top of one another. V. .\PETMM_basinAv_stoch.csv: This file contains the Souris River Basin average PET for each month of the stochastic PET time series. Column A is an unnamed index, column B, “simnum” is the simulation number, column C, “yr”, is the year in a stochastic simulation, and columns D through O are the PET values in millimeters for January through December, respectively. VI. .\PrecipMM_basinAv_stoch.csv: This file contains the Souris River Basin average precipitation for each month of the stochastic precipitation time series. Column A is an unnamed index, column B, “simnum” is the simulation number, column C, “yr”, is the year in a stochastic simulation, and columns D through O are the precipitation values in millimeters for January through December, respectively.