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Review of Sedimentation Issues on the Mississippi River

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Review of Sedimentation Issues on the Mississippi River Review of Sedimentation Issues on the Mississippi River Report Presented to the UNESCO: ISI Prepared by: Pierre Y. Julien and Chad W. Vensel Department of Civil and Environmental Engineering Colorado State University November 2005 Executive Summary Sedimentation on the Mississippi River and its major tributaries, like the Missouri, Ohio, and Illinois Rivers, has long been an issue of serious concern. Major tributaries and the delta area have been susceptible to significant changes in river discharge, cross section, width, mean bed elevation, water surface elevation, and sediment concentration. Additionally, water quality has become an issue of increasing concern throughout the basin due to the vast dependence of life on the river. The sedimentation issues have had broad effects upon several aspects of life, both terrestrial and aquatic, within the Mississippi River Basin. The size and dynamic nature of the Mississippi River Basin, have made the elimination of all sedimentation problems impossible. Several revetments, like dams, locks, levees, and dikes, have been implemented with the intent of mitigating these problems. The success of the revetments has generally been successful, although some negative derivatives have developed over time due to the presence of the revetments. Some problems have been aided by technological and educational advances, resulting in relatively simple solutions, like those associated with upland erosion and land use characteristics, while other issues like wetland subsidence and barrier fragmenting, have been extremely difficult to mitigate and continue to deteriorate with time. ii Table of Contents Table of Contents...............................................................................................................iii List of Figures.................................................................................................................... iv Introduction......................................................................................................................... 1 Background..................................................................................................................... 1 Purpose............................................................................................................................ 2 Objective......................................................................................................................... 2 Methodology................................................................................................................... 2 Water and Sediment Measurements.................................................................................... 2 Computational and Measurement Methods ........................................................................ 5 Upland Erosion ................................................................................................................... 9 Channel Dynamics and Processes..................................................................................... 11 Bed Forms..................................................................................................................... 11 Sediment Transport....................................................................................................... 12 Morphology and Migration........................................................................................... 18 Revetments.................................................................................................................... 21 Marsh and Wetland Impacts ............................................................................................. 30 Dredging ....................................................................................................................... 31 Delta and Shelf Processes ............................................................................................. 32 Water Quality.................................................................................................................... 42 Conclusion ........................................................................................................................ 47 References......................................................................................................................... 49 iii List of Figures Figure 1: Mississippi River drainage basin......................................................................... 1 Figure 2: Example of gaging stations, represented by black triangles, located within the state of Missouri.................................................................................................................. 3 Figure 3: Location maps, from the USGS, for the Mississippi River at St.Louis, MO gaging station...................................................................................................................... 3 Figure 4: Sample hydrograph, from the USGS, for the Mississippi River at St.Louis, MO gaging station...................................................................................................................... 4 Figure 5: Sample suspended sediment data for the Mississippi River at St.Louis, MO gaging station...................................................................................................................... 4 Figure 6: Observed and computed sediment concentration using the ANN approach....... 6 Figure 7: Observed and modeled sediment concentration using a phase-space reconstruction approach...................................................................................................... 7 Figure 8: Sheet erosion in the Upper Mississippi River basin............................................ 9 Figure 9: Areas of significant cropland erosion................................................................ 11 Figure 10: Rill erosion in the Mississippi River Valley ................................................... 13 Figure 11: Headcutting in the lower Missisisippi River. .................................................. 15 Figure 12: Confluence of the Mississippi and Missouri River in August of 1993. .......... 16 Figure 13: Aerial view of the Mississippi River before (top) and after the flood of 1993 (bottom)............................................................................................................................. 17 Figure 14: Levee failure on the Mississippi River during the 1993 flood event .............. 18 Figure 15: Evidence of channel migration in the Mississippi River................................. 19 Figure 16: Examples of a levee located in the upper Mississippi River........................... 21 Figure 17: Dike field in the lower Mississippi River........................................................ 22 Figure 18: Fort Peck dam in Montana on the Missouri River .......................................... 23 Figure 19: Lock and dam structure in the upper Mississippi River.................................. 24 Figure 20: Articulated concrete mattress installation in the upper Mississippi River ...... 25 Figure 21: Example of a channel bar formed as a result of revetments............................ 25 Figure 22: Dredging and revetments at Choctaw bar of the Mississippi River to improve navigation.......................................................................................................................... 26 Figure 23: Example of a cutoff bend in the lower Mississippi River ............................... 27 Figure 24: Atchafalaya control structure in the lower Mississippi River. ........................ 28 Figure 25: Regime of the Mississippi River ..................................................................... 29 Figure 26: Changes in sediment discharge in the Mississippi River Basin since 1940.... 30 Figure 27: Example of dredging on the Lower Mississippi River.................................... 31 Figure 28: Example of barrier island loss due to hurricane Katrina................................. 34 Figure 29: Marsh in the Mississippi River delta region.................................................... 36 Figure 30: Mississippi River sediment plume. ................................................................. 38 Figure 31: Marsh deterioration in the Mississippi River delta region .............................. 40 Figure 32: Wetland subsidence cycle and causes ............................................................. 41 Figure 33: Turbidity and tow traffic on the upper Mississippi River. .............................. 43 Figure 34: Confluence of Minnesota (lower) and Mississippi Rivers (upper) ................. 45 Figure 35: Water quality processes in the delta area of the Mississippi River................. 46 iv Introduction Background Sedimentation on the Mississippi River and its major tributaries, like the Missouri, Ohio, and Illinois Rivers, has long been an issue of serious concern (Figure 1). The sedimentation issues have had broad effects upon several aspects of life within the Mississippi River Basin. Recent advances have aided in the understanding and implementation of improvements within the basin. Problems like upland erosion, chemical leaks and spills, and other types of pollution have been prevalent throughout the basin and have been amplified by pollutant/sediment transport, creating environmental problems for humans, wildlife, and especially aquatic life. Several revetments have been implemented with the intent of mitigating these problems. The success of the revetments has generally
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