Authors: Chia-Yu Wu*, University of Florida, Joann Mossa, University of Florida
Topics: Geomorphology, Water Resources and Hydrology
Keywords: fluvial geomorphology, Mississippi River, riffles and pools
Session Type: Paper
Start / End Time: 10:00 AM / 11:40 AM
Room: Balcony K, Marriott, River Tower Elevators, 4th Floor
This study tend to analyze the riffle-pool morphology in the Lower Mississippi River (LMR)- a engineered river. LMR is one of the important river system in the North America– which is critical in term of environments and economies to the USA. Starting in the early 1990, many human activities impact and shape the Lower Mississippi River as one famous engineered river. Moreover, abundant of hydrological survey data in our study region, it is a unique opportunity to construct the historical trend of riffle-pool morphology variations; and investigate the relationship between physical variables and riffles pool sequence and channel morphology. Our study assesses the variation of channel geometry of LMR by using the hydrological data in 1961, 1991 and 2004, and create longitudinal profiles on river thalweg and identify the riffles and pools locations and their migration through the time.The preliminary results suggest that the spacing between successive pools is about 6-7 miles, which is similar to previous study by Hudson (2002). Moreover, the riffle-pool sequence migrations are shown in both long-term and short-term time scales. Also, our results suggest that riffle-pool morphology would change in engineered river. The riffle-pool variation in short-term time scale seems to be more stable; while strong sediment disturbance or deposition in long-term time scale. Local riffle-pool migration in short-term occurred due to artificial dams regulate or trap the sediments. In order to clearly delineate how the hydraulic variables affect the riffle-pool morphology, more future works that should be done.