Dayflow Version 1 (V1) is a historical streamflow reanalysis dataset reconstructed for a 36-year period (1980-2015). The dataset provides both daily and monthly scale streamflow information at about 2.7 million NHDPlusV2 stream reaches in the conterminous US (CONUS). Dayflow is the result of a nationally scalable modeling framework that integrates the simulated runoff from the Variable Infiltration Capacity (VIC) model with the Routing Application for Parallel computatIon of Discharge (RAPID) routing model. Two types of streamflow products, simulated streamflow with or without assimilation of historic US Geological Survey (USGS) streamflow observations, are provided in Dayflow V1. A comprehensive evaluation at 7,526 USGS National Water Information System (NWIS) gauges is performed for both types of streamflow products. The resulting key evaluation metrics are also included in the Dayflow V1 Dataset.
This dataset consist of 4216 netCDF files (2 files for each HUC8 region) that were derived from a nationally scalable modeling framework that integrates the simulated runoff from the VIC model with the RAPID routing model using high-performance computing. The VIC model employs calibrated parameters derived from Oubeidillah et al. (2014) and Naz et al. (2016). The observed streamflow is efficiently assimilated at USGS stream gauges using a simple hierarchical approach in the VIC-RAPID framework. The framework results in a reconstructed 36-year (1980–2015) daily and monthly streamflow dataset (Dayflow) at about 2.7 million NHDPlusV2 stream reaches in the Conterminous USA (CONUS).
File Naming Convention: Each data file is in the format of VIC4_RAPID_Obs2015C_HUC8Type_1980_2015.nc where HUC8 is the 8-digit hydrologic unit code and Type is the simulation type (N for naturalized and C for assimilated)
Temporal Resolution: daily and monthly
Temporal Coverage: 1980-2015