| Title: | Assessing environmental flow targets using pre-settlement land cover: A SWAT modeling application |
| Authors: | Zeiger, S.J. and J.A. Hubbart |
| Year: | 2018 |
| Journal: | Water |
| Volume (Issue): | 10(6) |
| Pages: | |
| Article ID: | 791 |
| DOI: | 10.3390/w10060791 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | land use change |
| Secondary Application Category: | hydrologic, pollutant and/or crop indices (or metrics) |
| Watershed Description: | 228 km^2 Hinkson Creek, located in central Missouri, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Determining environmental flow requirements to sustain aquatic ecosystem health
remains a challenge. The purpose of this research was to quantify the extent of current flow
alterations relative to baseline hydrologic conditions of a simulated historic flow regime prior to
anthropogenic flow disturbance (i.e., pre-settlement flows). Results allowed assessment of the efficacy
of environmental flow targets based on pre-settlement land cover in a contemporary mixed-land-use
catchment (i.e., urban, agricultural, and forested). Pre-settlement flows were simulated using
the Soil and Water Assessment Tool (SWAT). Pre-settlement land cover, based on soil physical
characteristics, was used to simulate pre-settlement flows with the SWAT model. Environmental
flow targets were calculated for each flow element of a historic flow regime (magnitude, frequency,
duration, timing, and rate of change). Urban (20% of watershed area) and agricultural development
(42% of watershed area) were correlated to decreased median daily stream flow by 0.8 m3 s-1
(percent difference = -115%), increased maximum daily flow by 22 m3 s-1 (percent difference = 13%),
and a 34% increase in daily flow variability. High flow frequency increased by 45–76% following
development. Results highlight a need for consideration of environmental flow targets appropriate
for watersheds already modified by existing land use, and point to a need for long-term, broad-scale,
and persistent efforts to develop achievable environmental flow recommendations, particularly in
rapidly urbanizing mixed-land-use watersheds. |
| Language: | English |
| Keywords: | environmental flows; ELOHA; ecohydrology;mixed-land-use hydrology; SWAT; EflowStats |