HAWQS Models
We compared observed flow data to flow predictions obtained from the
Oklahoma Hydrologic and Water Quality System (HAWQS) model, a web-based
tool using the Soil and Water Assessment Tool (SWAT) modeling framework,
using standard settings for three drainages in the Glover River (EPA
2017). We selected only three drainages because their predetermined
boundaries roughly aligned with our study sites (Figure 1). No data was
available when field sampling occurred (2021-2022), so we used data from
the Mt. Herman Mesonet site (Mesonet 2023) to select ten years (April
through March) with similar (within 15%) total precipitation as our
study period and ran the HAWQS model for each of those periods. We
compared four hydrologic metrics (skew, number of no-flow days, high
pulse count, and number of reversals) from the HAWQS output to our
observed field data. We considered any day where the predicted flow was
less than 0.01m3/s to be a no-flow day and required a
change of more than 10% of mean daily flow to be considered a reversal,
in order to minimize the impact of negligible variation resulting from
modeling processes.