1. Changes in the Discharge of Suspended Sediment along the Missouri-Mississippi River System, 1940-2007 VIII ENES, Campo Grande, Brasil 6 November 2008 John Moody and Bob Meade

2. Introduction Bob Meade John Moody

3. Motivation: New Orleans after Hurricane Katrina Photos: Smiley N. Pool and Michael Amsworth, WWLTV

4. Because deposition constructs barrier islands and wetlands that are protection for New Orleans Remember that sediment deposition can be good

5. Some Candeleur islands before Katrina Two days after Katrina

6. Summary of talk 1.Virtual tour a.Landscapes along the Missouri and Mississippi b.Engineering activities along the Missouri and Mississippi River System 2.The mystery of the missing sediment

7. Rainbow Great Falls of the Missouri River River Horseshoe Black Eagle Note: water has little sediment Montana

8. Photo by Bob Lindholm Airphoto-Jim Wark Missouri Breaks Montana Note: water has little sediment

9. Missouri Breaks McClelland Ferry Montana Note: water has little sediment

10. Fort Peck Dam View: upriver Montana

11. Confluence below Fork Peck Dam Rio Milk Rio Missouri Montana Airphoto-Jim Wark Note: water of the Missouri River has little sediment Vista: abaixo

12. Reservoir Francis Case Upriver from Fort Randall Dam in South Dakota Meade 2002 South Dakota

13. Fort Randall Dam Fort Randall Dam on Missouri River

14. Yankton South Dakota Gavins Point Dam on Missouri River Free-flowing Missouri River begins here

15. View: downriver from Gavins Point Dam Yankton Nebraska 1.8 million t/a

16. Rio Missouri Bodmer Loess bluffs Omaha, Nebraska Moody Eppley Airport 1833 2002 Omaha Nebraska

17. Missouri River in Omaha, Nebraska Omaha Nebraska 26 million t/a

18. Nebraska Kansas Pile Dikes Indian Cave Bend View: downriver

19. Adapted from Funk and Robinson, 1974 -49% Water -41% Channels -99% Islands Channelization of Missouri River Reduced source of sediment and increased storage in new floodplains

20. Airphoto-Jim Wark View: Upriver Confluence of the Osage and Missouri Missouri Kansas

21. Photo: R. Stallard Missouri Storage of sediment behind dikes Missouri River at Mile 189 View: Downriver

22. Missouri River at Hermann, Missouri View: Upriver Hermann Missouri 88 million t/a

23. 0 50 milhão t/a Adapted from Parker, 1988, IAHS Pub. 174 Increase in suspended sediment discharge principle from loess landscape in Iowa Iowa ~ 60 million t/a Total = 88 million t/a Missouri Iowa Confluence of the Missouri and Nishnabotna Rivers Missouri Yankton Hermann

24. Wing Dams or Rock Dikes L-Dikes View: below Hermann and upriver Missouri 400 m

25. Missouri Sand dredging in the Missouri River near St. Louis, Missouri

26. Missouri Illinois St. Louis Missouri Illinois St. Louis Mississippi in St. Louis, Missouri 97 million t/a View: from the left bank

27. Missouri Illinois Mississippi River at Cape Girardeau, Missouri View: Upriver Bank revetment

28. Mississippi River Upper Mile 51.0 Missouri Illinois L-Head dike

29. Missouri Illinois Mississippi River Upper Mile 37 Alternate dikes

30. Missouri Illinois Mississippi at Thebes, Illinois View: downriver The end of rocky outcrops along the banks

31. Missouri Kentucky Tennessee Ohio Mississippi Confluence of the Ohio and Mississippi Rivers View: downrivier 800 m

32. Mississippi River at Mile 388 Bank protection and trapping of the sediment Vegetation mat with rock protection at the toe of the bank Articulated concrete mat

33. Red River Mississippi River Atchafalaya River Mississippi River Tarbert Landing Knox Landing Simmesport Old River Outflow Channel Navigation Lock Low-sill Hydropower dam Auxiliary control Arkan- sas Louis- iana

34. 0 10 20 Profundidade, m 02004006008001000 Q = 21,000 m 3 s -1 Lagura, m Velocity, m s -1 0 2.0 1.0 Mississippi River at Arkan- sas Louis- iana Tarbert Landing, Mississippi 190 million t/a

35. Ohio Missouri Ohio Missouri Flux of water and suspended sediment from the Mississippi River Catchment about 1980

36. Louis- iana Lake Pontchartrain Mississippi River flowing through New Orleans Louis- iana

37. Mouth of the Mississippi River Gulf of México

38. Barrier island protection the coast of New Orleans

39. The mystery of the missing suspended sediment at Tarbert Landing Integrated bag sampler

40. Significant decline after 1800 Suspended sediment discharge, million t/a 0 200 400 cerca de 1800 cerca de 1980cerca de 1800cerca de 1980about 1800about 1980

41. Sediment Water Mississippi River at Tarbert Landing Sediment Water Million t/a km 3 / a Water year in northern hemisphere (October through September) 190 130 ~ 370 million t/a

43. Tarbert Landing Hermann Omaha Yankton Sediment Water = Amount entering between Omaha and Hermann km 3 / a Sediment Water 0 50 million t/a Adapted from Parker, 1988, IAHS Pub. 174 Hermann Omaha Milhões t/a Water year in the northern hemisphere

44. Other causes Annual suspended-sediment discharge, million metric tons Cumulative protection of the bank or cumulative construction of dikes, kilometers Bank protection dikes year ~ 150 million t/a ~ ??? million t/a

45. Other causes Soil conservation USDA Photo: Tim McCabe ~ 150 million t/a ~ ??? million t/a Area, ha Many small reservation in catchment of the Missouri River

46. Effect: Change in the C-Q relation Tarbert Landing 1950-1966 1967- 2007 C Mean annual concentration of suspended sediment, mg / L Q, Water discharge, km 3 / a Transport-limited system Supply-limited system ~ 150 million t/a ~ ??? million t/a

47. Our Conclusions and Thoughts 1.Some of the missing sediment is behind the large dams. 2.Structures like dikes and “wing dams”, designed to protect banks store sediment and prevent erosion of the sediment. 3.Soil conservation probable has bee effective in reducing the sediment discharge to the Missouri-Mississippi River system. 4. The Missouri-Mississippi system has changed from transport limited system to a supply-limited system.

48. 5. Sediment deposition can be a problem and sediment deposition can be beneficial depending upon the human assessment of the situation.. 6. We need to continue to collect good data on sediment discharge. Good data lives forever and are fundament to modeling sediment transport. Good data lives forever and are fundament to modeling sediment transport. Models should only be used to synthesize the data. In the world of “non-stationary”, continuity of data is critical. Our Conclusions and Thoughts

49. 7.The scientific paper in press on this subject could not have been possible without data collected over a long period of time (decades) 8. We need to understand river ecosystems completely and not only in terms of engineering structures. Our Conclusions and Thoughts

50. 9. “Lean by listening and observing the river— each river is different.”. Our Conclusions and Thoughts

51. Obrigado por sua atenção. Questões?