This dataset consists of daily streamflow percentiles for 1981-10-01 to 2020-03-31 relevant to streamflow drought defined using two approaches: Percentiles accounting for flow seasonality (variable threshold percentiles) and those based on the full record of data for each site regardless of season (fixed threshold percentiles). Because of the size of this dataset (99,530,836 rows), it could not be provided as a .csv file, and is instead provided as a .parquet file. Instructions on reading this file using the R programming language are provided in the Processing Step section of this metadata. The daily streamflow percentiles were estimated for ungaged areas of the Colorado River Basin (CRB) using neural network models, specifically long short-term memory (LSTM) models, by scientists on the USGS Data-Driven Drought Prediction project. The models were trained on data from 391 streamgages in the CRB and surrounding region and then used to generate predictions at ungaged stream locations within the CRB. Data from 01-Oct-1981 to 31-Mar-2014 was used to train the model with validation over the period of record spanning 01-Apr-2014 to 31-Mar- 2020. The models use explanatory variable inputs described in Wieczorek (2023) (doi.org/10.5066/P98IG8LO) to predict daily streamflow and streamflow percentiles as described in Simeone (2022) (doi.org/10.5066/P92FAASD). Model predictions are provided for 3,539 ungaged area spatial units from the National Hydrologic Geospatial Fabric version 1.1 (Bock et al., 2020) across the CRB. A follow up set of predictions is planned, with those predictions based on a models using a greater number of predictor variables including variables quantifying human flow alteration.

This metadata record describes a series of tabular datasets containing metrics used to characterize drought for select United States Geological Survey (USGS) streamgages in and surrounding the Colorado River Basin for the climate years (April 1 – March 31) 1981 to 2020. These streamgages are a subset of those used in Geospatial Attributes of Gages for Evaluating Streamflow, version 2 (GAGES-II, Falcone, 2011) with some additional USGS streamgages not in the GAGES-II dataset added. The metrics include streamflow percentiles, identified drought events, annual low streamflow, and statistics for each drought event.

This metadata record describes a series of tabular datasets containing metrics used to characterize drought for select United States Geological Survey (USGS) streamgages in and surrounding the Colorado River Basin for the climate years (April 1 – March 31) 1981 to 2020. These streamgages are a subset of those used in Geospatial Attributes of Gages for Evaluating Streamflow, version 2 (GAGES-II, Falcone, 2011) with some additional USGS streamgages not in the GAGES-II dataset added. The metrics include streamflow percentiles, identified drought events, annual low streamflow, and statistics for each drought event.

These tabular data sets represent daily climate metrics processed from 4 kilometer GridMET data (Abatzoglou, 2013) for the period of record 1980 through 2020 and compiled for three spatial components: select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper and Lower Colorado (ucol) portions of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values were computed using the published python software package Xstrm (Wieferich and others). The following daily climate metrics were processed: minimum and maximum temperature (Celsius), precipitation (millimeters), potential evapotranspiration (millimeters), reference evapotranspiration (millimeters), and 5 day standardized precipitation evapotranspiration index (unitless).

These tabular data sets represent daily climate metrics processed from 4 kilometer GridMET data (Abatzoglou, 2013) for the period of record 1980 through 2020 and compiled for three spatial components: select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper and Lower Colorado (ucol) portions of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values were computed using the published python software package Xstrm (Wieferich and others). The following daily climate metrics were processed: minimum and maximum temperature (Celsius), precipitation (millimeters), potential evapotranspiration (millimeters), reference evapotranspiration (millimeters), and 5 day standardized precipitation evapotranspiration index (unitless).

These tabular datasets represent retrospective forecasts of average minimum temperature (degrees Celsius), maximum temperature (degrees Celsius), and total precipitation (millimeters) within three-hour forecasting periods derived from the Global Ensemble Forecast System (GEFS) reforecast dataset (Hamill and others, 2013). Data are averaged across 7 day forecast horizons for each day within the period of record spanning 2000 through 2019. The data were compiled for two spatial components: 1) select United States Geological Survey streamgage basins (Staub and others, 2023), 2) individual reach flowline catchments of the Upper Colorado (ucol) portion of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (Bock and others, 2020). Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021).

These tabular data sets represent the average daily soil moisture water content (kg/m^2) for four different soil layers processed from North American Land Data Assimilation System (NLDAS-2) data (Xia and others, 2012) for the period of record 1980 through 2020 and compiled for three spatial components: 1) select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper Colorado (ucol) portion of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Upstream watershed values for each reach catchment were computed using the published python software package Xstrm (Wieferich and others). The following mean daily soil moisture water content layers were processed: 0-10 centimeters, 10-40 centimeters, and 40-100 centimeters.

These tabular data sets represent daily climate metrics processed from 4 kilometer GridMET data (Abatzoglou, 2013) for the period of record 1980 through 2020 and compiled for three spatial components: select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper and Lower Colorado (ucol) portions of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values were computed using the published python software package Xstrm (Wieferich and others). The following daily climate metrics were processed: minimum and maximum temperature (Celsius), precipitation (millimeters), potential evapotranspiration (millimeters), reference evapotranspiration (millimeters), and 5 day standardized precipitation evapotranspiration index (unitless).

These tabular data sets represent the average daily soil moisture water content (kg/m^2) for four different soil layers processed from North American Land Data Assimilation System (NLDAS-2) data (Xia and others, 2012) for the period of record 1980 through 2020 and compiled for three spatial components: 1) select United States Geological Survey stream gage basins (Staub and Wieczorek, 2023), 2) individual reach flowline catchments of the Upper Colorado (ucol) portion of the Geospatial Fabric for the National Hydrologic Model, version 1.1 (nhgfv11, Bock and others, 2020 ), and 3) the upstream watersheds of each individual nhgfv11 flowline catchments. Flowline reach catchment information characterizes data at the local scale using the python tool set called gdptools (McDonald, 2021). Upstream watershed values for each reach catchment were computed using the published python software package Xstrm (Wieferich and others). The following mean daily soil moisture water content layers were processed: 0-10 centimeters, 10-40 centimeters, and 40-100 centimeters.

Identifying long-term trends in water availability, including surface water quantity, is a key part of the U.S. Geological Survey (USGS) Integrated Water Availability Assessments (IWAAs) mission. This data release includes input and output data used in Mann-Kendall trend analyses to characterize streamflow conditions at 124 USGS streamgages in the Upper Colorado River Basin for water years 1982 through 2021. The Upper Colorado Riven Basin is defined here as the basin area upstream of USGS streamgage Colorado River above Lee's Ferry, AZ (USGS site number 09380000). Input data included annual (111 streamgages), seasonal (119 streamgages), and monthly (121 streamgages) streamflow metrics, calculated from daily mean streamflow data from the USGS National Water Information System (NWIS) database. Annual streamflow metrics include mean and median annual streamflow, 1-day, 7-day, and 30-day maximum annual streamflow; 1-day, 7-day, and 30-day minimum annual streamflow; and the date of the center of volume (the date on which 50 percent of the annual streamflow has passed by a streamgage). Seasonal metrics were calculated for Fall (October-December), Winter (January-March), Spring (April-June), and Summer (July-September) and include mean and median seasonal streamflow, 1-day and 7-day maximum seasonal streamflow, and 1-day and 7-day minimum seasonal streamflow. Monthly metrics include mean and median monthly streamflow, 1-day and 7-day maximum monthly streamflow, and 1-day and 7-day minimum monthly streamflow. Trend analyses using the Mann-Kendall test were completed on the annual, seasonal, and monthly metrics, which were passed through a series of data completeness filters to ensure robust trend analyses. Trend analyses were conducted for climate years 1982 through 2021 for low-flow metrics (where each climate year represents April – March), and trend analyses were conducted for water years 1982 through 2021 for all other metrics (where each water year represents October – September).