PRMS Flow Model Output

The PRMS computes flow generated locally on each HRU for each time step. These flow components then are directed to stream segments (SEGs) for flow aggregation. These segments connect the network of HRUs to simulate accumulated streamflow from the upstream watershed. Each HRU and SEG has a unique ID. For each HRU and SEG, 52 summary streamflow metrics (Index of Hydrologic Alteration or IHA metrics) were calculated based on the daily flow outputs. A description of each IHA metric may be found here (streamflow_description_table.xlsx).

The summary information presented here shows geospatial results from three main components:

1) The model domain for HRUs (local watersheds) and SEGs (accumulated flow segments). Each HRU and SEG is labeled with a unique ID may be associated with model results using this unique ID. Original data here: https://www.sciencebase.gov/catalog/item/597f2f6ce4b0a38ca2774b3f

2) The future percent difference from historical conditions for each HRU and SEG and for each of 50 IHA metrics (two metrics excluded due to a predominance of missing values). The results are based on the difference between future conditions in 2045-2075 and historical conditions from 1952-2005. Values are expressed as the percent difference based on a median of 45 future scenarios. https://www.sciencebase.gov/catalog/item/597b37bbe4b0a38ca27563d4

Data source - HRU: “Summary of percent change in statistics by GCM/RCP scenario by HRU”
stats_difference_hru_gcm_v2_csv
Data source - SEG: “Summary of percent change in statistics by GCM/RCP scenario by SEG”
stats_difference_seg_gcm_v2_csv

3) Results from a test (Kolmogorov-Smirnov or KS test) of model agreement. Results are measure of the model skill in accurately reproducing observed historical conditions. Higher values means higher confidence in model output. Lower values means lower confidence in model output. Data sources: not published?

Purpose
The streamflow statistics were selected to describe streamflow conditions that may be most useful in defining the suitability for each river or stream to support sustaining populations of priority aquatic species across the GCPO LCC. The data presented here are intended to provide more easily accessible landscape scale summary information in support of the USGS flow modeling project.