Preliminary streamflow percentile predictions for ungaged areas of the Colorado River Basin, 1981-2020

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.