Conclusion
When water level oscillations are present, the amplitude and inundation area of flood events increase. This is especially present in the estuary downstream part of North Fish Creek. The influence of the water level oscillations decrease along the upstream and the uppermost stream limits (~19 kilometers upstream) show little to no influence. Additionally, the presence of water level oscillations in Chequamegon Bay may influence the routing of floods, as found by the 2D HEC-RAS model. This may change the spatial geometry as well as the size of the inundation areas under these conditions.
During steady state stream conditions (i.e. normal non-flooding conditions), water level oscillations in Chequamegon Bay induce a larger water depth in the estuary downstream zone. During flooding events, the water level oscillations in the Bay have less of an effect of water depth in the estuary downstream zone.
During steady state stream conditions (i.e. normal non-flooding conditions), water level oscillations in Chequamegon Bay show little influence in the midstream zone (~7 kilometers upstream). However, during flooding events, the water level oscillations in the Bay induce larger water depth changes in the midstream zone.
Larger flooding events combined with water level oscillations in Chequamegon Bay seem to significantly change the water depth profiles in the estuary downstream zone. Additionally, a flood event with a shorter period may have a stronger influence on the water depth profiles in the upstream zone, as found by the 2D model.
Last, in this particular study, a 2D HEC-RAS model is better-suited to simulate the conditions at the necessary levels of detail. The 1D model was limited by the number of viable cross-sections added and doesn't model changes in flow like the 2D model can. The 2D model application is able to calculate flow direction changes within the flow area whereas the 1D model flow direction is constrained by the cross-section geometry. Having said that, the 1D model was useful to compare results generated by the 2D model. The 1D model was able to produce results at a more general level and the 2D model added an extra level of detail. In general, choosing between the two models should be applied based on the needs of the study area, project, or desired results