Regional Environmental Flow Estimation for Watersheds in West Tennessee
Abstract
A majority of streams in West Tennessee are formed in the Southeastern plains and flow through the Mississippi Valley Loess Plains before discharging into the Mississippi River. There are six major watersheds in West Tennessee: Forked Deer, Hatchie, Loosahatchie, Wolf, and Nonconnah that covers approximately 25,000 sq km area. Maintaining sufficient streamflow during the dry season is critical to the agriculture and ecology of this region. Due to historic land-use changes and channelization, it is important to identifying restoration opportunities to restore streamflow to address these needs in this region. While United States Geological Survey's (USGS) National Hydrography Dataset (NHD) and StreamStats provide monthly average flow and flows at various probability of duration for the streams of this region, there is no common database for environmental flow (EF) needs in the streams of West Tennessee. Therefore, the objective of this research is to develop a regional EF dataset for the streams in these West Tennessee watersheds. We used multiple hydrological methods such as Tennant, Flow Duration Curve (FDC) shifting, 7-day-10-year low flow index (7Q10), and 90 percent duration (D90) to estimate EF on 17000 NHD Plus v2.1 stream segments. Using model selection and k-fold resampling techniques, we then trained and tested multiple linear regression models for predicting individual input parameters (for EF methods) using StreamStat station report and Environmental Protection Agency's (EPA) SteamCat watershed data. Our results suggest that the majority of perennial streams in West Tennessee require 20% - 30% of the annual average streamflow to maintain EF during the dry season. This dataset is expected to act as a basis for defining existing water availability along with ecological and restoration needs in West Tennessee.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH004.0007B
- Keywords:
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- 1847 Modeling;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY;
- 1879 Watershed;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY