Effectiveness of wetland restoration in mitigating extreme streamflows under future climate change in the White River watershed of Indiana
A research project funded by the Indiana Water Resources Research Center through the U.S. Geological Survey’s 104B annual base grants (section 104 of the Water Resources Research Act of 1984, as amended).
Start Date: 2019-05-31 End Date: 2020-05-30
Total Federal Funds: $15,000 Total Non-Federal Funds: $31,080
Climate change directly affects the availability of water resources in the US Midwest, including Indiana. It is projected that Indiana’s warming rate is accelerating, with an increase of precipitation in winter and spring. Indiana will experience drier and warmer crop growing seasons and wetter winters in the future. These conditions lead to various water management challenges in Indiana, including adaptation to more flooding and droughts and potentially a shift from rainfed agriculture to irrigation agriculture.
Wetlands are known to buffer streamflow by intercepting surface and sub-surface flows, thereby helping mitigate extreme flooding and droughts. Current restoration decisions usually focus on individual wetland projects and local site conditions, thus missing the aggregated effects of hydrologically connected wetlands at the watershed scale.
Figure 1. White River Watershed and the Current and Historical Wetland Distribution.
- Better understand and quantify how wetland restoration will impact future streamflow regimes and help mitigate extreme flooding and drought events using a case study site, the White River watershed, a typical Midwest watershed with heavy agricultural practices and shrinking watersheds. This project used the Hydrological Simulation Program-FORTRAN model to design two scenarios of climate change and three scenarios of wetland restoration as applied to the White River watershed to determine:
- How future climate change in the White River watershed affects streamflow and surface water availability,
- How wetland restoration helps buffer high and low streamflows, and
- What are suggested plans for water conservation officials to consider under different future climate change scenarios.
- Serve as a pilot project for the fundraising and installation of additional continuous flow monitoring systems.
Major Conclusions & Significance
The project has supported scenario-based hydrological modeling, and statistical analysis and modeling of water quality and streamflow changing trends of the White River watershed. Approaches employed in this project include land use change scenarios, experimental data compiled from literature, climate data analysis, statistical modeling, and an easy-to-adopt nutrient simulation model.
Primary findings include:
- Sensitive areas in the White River watershed for nutrient release and projected the comparisons under various land use scenarios into the future, and
- Increasing trend of BOD and nitrogen, and a decreasing trend of DO in the White River near Muncie over the past two decades.
What Does This Mean For Indiana?
The long-term statistical analysis and modeling of the water quality reveals the changing trends and potential pollution sources in the Upper White River watershed of Indiana. The approaches and outcomes will be beneficial to local communities and may easily be applied to other agriculture-dominate Midwest regions.
Training The Next Generation
One of the missions of the Indiana Water Resources Research Center, and all Water Centers, is to train the next generation of water scientists. This project successfully funded research for two Masters students and one Ph.D. student within Dr. Han’s lab and trained two undergraduate researchers.
This study will help advance the understanding of wetland functions at the watershed scale, while also assisting elected officials at the state and local levels, decision makers, and local communities to better adapt to future climate change when making restoration plans to support soil and water conservation and healthy wetlands.