Identification of biological protection zones in Coastal Plain rivers of Southeastern U.S.

The University of Alabama in collaboration with the University of Alabama in Huntsville is conducting research to evaluate the potential long term biological impacts caused by water withdrawals in four Coastal Plain rivers of the Southeastern United States.  In the case of a severe, long-term change in precipitation patterns, a large portion of U.S. grain production located in the Great Plains and Midwest might be severely affected.  As a climate change adaptation strategy, we are exploring the feasibility of increasing the potential for grain production in the Southeast U.S. through increased irrigation. The objective of the strategy is to off-set short-term seasonal droughts by storing river water during winter months in ponds, to be used later during drier periods in the growing season. One of the goals of the project is to estimate the amount of water that can be withdrawn from river and floodplain ecosystems without long-term harm to existing floodplain habitats. Preliminary analyses of these four river floodplains reveal that isolated, ephemeral wetlands most frequently occur near main river channels. Water withdrawal strategies should be designed to protect these critical high productivity habitats by maintaining their natural flooding regimes and connectivity to the river. 1D and 2D hydraulic models were used to understand the dynamics of these wetlands and the surface hydrologic connectivity between the wetlands and the main stream. This presentation shows the results of several computer models including HEC-RAS, PCSWMM, FLO-2D, and Delft-3D created for a small section of a floodplain river located near Tuscaloosa, Alabama.