An approach for prioritizing natural infrastructure practices to mitigate flood and nitrate risks in the Mississippi-Atchafalaya River Basin

Authors: SCHILLING, KEITH - University Of Iowa; MOUNT, JERRY - University Of Iowa; SUTTLES, KELLY - Environmental Defense; MCLELLAN, EILEEN - Environmental Defense; GASSMAN, PHILIP - Iowa State University; White, Michael; Arnold, Jeffrey

Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2023
Publication Date: 1/18/2023
Citation: Schilling, K.E., Mount, J., Suttles, K., Mclellan, E., Gassman, P.W., White, M.J., Arnold, J.G. 2023. An approach for prioritizing natural infrastructure practices to mitigate flood and nitrate risks in the Mississippi-Atchafalaya River Basin. Land. 12:276. https://doi.org/10.3390/land12020276.
DOI: https://doi.org/10.3390/land12020276

Interpretive Summary: The Mississippi-Atchafalaya River Basin is prone to both flooding and excessive nitrate pollution, both of which cause widespread societal harm. In this study we seek to identify effective natural infrastructure (NI) conservation practices and the best locations to place them within the basin to address these issues. Spatial data with a 10 m resolution were used to prioritize the most effective locations for NI practice placement to minimize flooding and water quality risks in the basin. Results from this study are a launching point from which to improve future placement and selection of NI practices to reduce flooding and improve water quality.

Technical Abstract: Societal risks from flooding and poor water quality are evident at a range of spatial scales and climate change will exacerbate these risks in the future. Natural infrastructure (NI) consisting of structural or perennial vegetation measures that provide multiple ecosystem benefits have potential to reduce flood and water quality risks. In this study, we intersected watershed-scale risks to flooding and nitrate export in the Mississippi- Atchafalaya River Basin (MARB) of the central U.S. with potential locations of seven NI practices (land use change, water and sediment control basins, depressional wetlands, nitrate-removal wetlands, riparian buffers, and floodplains levees and land use change) to prioritize where NI can be most effective for combined risk reduction at watershed scales. Spatial data were analyzed at a 10 m grid cell to locate NI practices and NI practices were presented at the regional basin scale and local Iowa-Cedar watershed in eastern Iowa to show individual practice locations. A prioritization scheme was developed to show the optimal watersheds for deploying NI practices to minimize flooding and water quality risks in the MARB. Study results are considered to be a launching point from which to improve the connections between watershed scale risks and potential use of NI practices to reduce these risks.