Growing populations and industrialized agriculture practices have eradicated much of the United States wetlands along river floodplains. One program available for the restoration of floodplains is the Conservation Reserve Program (CRP). The current research explores the effects CRP land change has on flooding zones, utilizing Flood Modeller and HEC-RAS. Modelling in both one-dimensional and two-dimensional approaches were tested and analyzed for the same river reach. Flood Modeller is proven a viable tool for flood modeling within the United States when compared to HEC-RAS. Application of the software is used in the Nodaway River system located in the western halves of Iowa and Missouri, to model the effects of introducing new forest areas within the region. Flood stage during the conversion first decreases in the early years, before rising to produce greater heights. Flow velocities where CRP land is present are reduced for long-term scopes. Velocity reduction occurs as the Manning’s roughness values increase due to tree diameter and brush density. Flood zones become more widespread with the implementation of CRP. Comparing one-dimensional and two-dimensional flood mapping zones, the two-dimensional model shows less inundation. CRP land cover effects evolve over time, with the greatest impact appearing at the end of the contract.

This research is part of an ongoing effort to improve predictions for bathymetric and morphological changes in the Lower Mississippi River. The utilized model is a subset of a previously calibrated Delft3D model. This shorter model has reduced computational time, and can be deployed for analysis focused on the area between Belle Chasse and HOP, which is the domain of the model. Simulation runs conducted under this study vary from 12 years to 48 years, utilizing a developed 12-year variable hydrograph. The comparison of variable annual hydrograph and repeated representative annual (uniform) hydrograph input data on bathymetric changes indicated that the absolute bathymetric equilibrium is dependent on year to year variability. The utilization of a uniform hydrograph increases the predicted deposition within the river domain. When evaluating diversion sand capture, utilizing a uniform hydrograph can be considered a conservative approach, while utilizing a variable hydrograph will result in more accurate sand load volumes captured by the diversion.In general, sediment capture showed only minor interdependencies amongst multiple diversions, as long as the total diversion flow is less than 140,000cfs. This study shows that morphological changes are dependent on the number and location of multiple diversions. The largest interdependencies occur for the most downstream diversions, which increase with the total diverted flow. A true equilibrium was not achieved within 48 years, with or without sea level rise. It was observed, that the system with diversions responds to sea level rise by an increase in deposition, which increases with total diverted flow.