Changes in the Discharge of Suspended Sediment along the Missouri-Mississippi River System, 1940-2007

VIII ENES, Campo Grande, Brasil6 November 2008

John Moody and Bob Meade

IntroductionIntroduction

Bob MeadeBob MeadeJohn MoodyJohn Moody

Motivation: New Orleans after Hurricane Katrina

Photos: Smiley N. Pool and Michael Amsworth, WWLTV

Because deposition constructs barrier islands and wetlands that are protection for New Orleans

Remember that sediment deposition can be good

Some Candeleur Some Candeleur islands before islands before KatrinaKatrina

Two days after Two days after KatrinaKatrina

Summary of talkSummary of talk

1.1. Virtual tourVirtual tour

a.a. Landscapes along the Landscapes along the Missouri Missouri and and MississippiMississippi

b.b. Engineering activities along the Engineering activities along the Missouri Missouri and and Mississippi River Mississippi River SystemSystem

2.2. The mystery of the missing sedimentThe mystery of the missing sediment

Rainbow

Great Falls of the Missouri River River

Horseshoe

Black Eagle

Note: water has little sediment

Montana

Photo by Bob LindholmAirphoto-Jim Wark

Missouri BreaksMontana

Note: water has little sediment

Missouri BreaksMissouri Breaks

McClelland McClelland FerryFerry

Montana

Note: water has little Note: water has little sedimentsediment

Fort Peck DamFort Peck Dam

View: upriverView: upriver

Montana

Confluence belowConfluence below

Fork Peck DamFork Peck Dam

Rio Milk

Rio Missouri

Montana

Airphoto-Jim Wark

Note: water of the Missouri River has

little sedimentVista: abaixoVista: abaixo

Reservoir

Francis Case

Upriver from

Fort Randall Dam

in South DakotaMeade 2002

South Dakota

South Dakota

Fort Randall DamFort Randall Dam

on on Missouri RiverMissouri River

Yankton

South Dakota

Gavins Point DamGavins Point Dam

on on Missouri RiverMissouri River

Free-flowing Missouri

River begins here

View: downriver

from

Gavins Point Dam

YanktonNebraska

1.8 million t/a

Rio Missouri

Bodmer

Loess bluffsLoess bluffs

Omaha, Nebraska

Moody

Eppley Airport

1833

2002

OmahaNebraska

Missouri River in

Omaha, Nebraska

OmahaNebraska

26 million t/a

Nebraska

Kansas

Pile Dikes

Indian Cave Bend

View: downriver

Adapted from Funk and Robinson, 1974

-49%

Water

-41%Channels

-99%Islands

Channelization of Missouri RiverReduced source of sediment and increased storage in new

floodplains

Airphoto-Jim Wark

View: Upriver

Confluence of the Osage and Missouri

Missouri

Kansas

Photo: R. Stallard

Missouri

Storage of sediment behind dikes

Missouri River at Mile 189

View: Downriver

Missouri River at Hermann, Missouri

View: UpriverHermann

Missouri

88 million t/a

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

MissouriYanktonYankton

HermannHermann

Wing Dams

or Rock Dikes

L-Dikes

View: below Hermann and upriver

Missouri

400 m400 m

Missouri

Sand dredging in the

Missouri River

near

St. Louis, Missouri

Missouri

IllinoisSt. LouisMissouri

IllinoisSt. Louis

Mississippi in

St. Louis, Missouri

97 million t/a

View: from the left bank

Missouri

Illinois

Mississippi River at

Cape Girardeau, Missouri

View: Upriver

Bank revetment

Mississippi River Mississippi River Upper Mile 51.0Upper Mile 51.0

Missouri

Illinois

L-Head dikeL-Head dike

Missouri

Illinois

Mississippi River Upper Mile 37

Alternate dikes

Missouri

Illinois

Mississippi at

Thebes, Illinois

View: downriver

The end of rocky

outcrops along the

banks

MissouriKentucky

Tennessee

Ohio Mississippi

Confluence of the Ohio and Mississippi

Rivers

View: downrivier

800 m

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

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

0

10

20

Pro

fun

did

ade,

m

0 200 400 600 800 1000

Q = 21,000 m3 s-1

Lagura, m

Velocity, m s-1

0 2.01.0

Mississippi River

at Arkan-

sas

Louis-iana

Tarbert Landing, Mississippi

190 million t/a

Ohio

Missouri

Ohio

Missouri

Flux of water and suspended sediment from the Mississippi River Catchment

about 1980

Louis-iana

Lake Pontchartrain

Mississippi River Mississippi River flowing throughflowing through

New OrleansNew Orleans Louis-iana

Louis-iana

Mouth of theMouth of the

Mississippi RiverMississippi River

Gulf of MéxicoGulf of México

Barrier island Barrier island protection the coast of protection the coast of

New OrleansNew Orleans

The mystery of the missing The mystery of the missing suspended sedimentsuspended sediment

at at

Tarbert Tarbert LandingLanding

Integrated bag Integrated bag samplersampler

Significant decline after 1800

Suspended sediment discharge, million t/a

0 200 400

cerca de 1800 cerca de 1980cerca de 1800 cerca de 1980about 1800 about 1980

0

200

400

600

1950 1960 1970 1980 1990 2000

Water year

Cu

bic

km

per

yea

r

0

100

200

300

400

500

1950 1960 1970 1980 1990 2000

Mil

lio

ns

of

ton

s p

er y

ear

Sediment

Water

Mississippi River at Tarbert Landing

Sediment

Water

Mill

ion

t/a

km

3 / a

Water year in northern hemisphere (October through September)

190130

~ 370 million t/a

0

100

200

300

400

500

600

1950 1960 1970 1980

Water year

Millio

ns o

f to

ns p

er

ye

ar

One cause: Effect of damsclosed

110 million t/a40 million t/a

~ 150 million t/a

Mil

hões

t/a

0

100

200

300

1940 1950 1960 1970 1980

0

100

200

300

400

0

100

200

300

1940 1950 1960

Yankton

Omaha

Hermann

Tarbert Landing

Gavins Point Dam

Fort Randall Dam

CanadaUSA

Gulf of Mexico

Missouri River

Miss

issip

pi R

iver

Ohio River

0 500

kilometers

N

Amount entering between Omaha and Hermann

Water year in the northern hemisphere

0

200

400

600

1950 1960 1970 1980

Water year

Cu

bic

km

per

yea

r0

100

200

300

400

500

600

1950 1960 1970 1980M

illi

on

s o

f to

ns

per

yea

r

Tarbert Landing

Hermann

Omaha

Yankton

Sediment

Water

= Amount entering between Omaha and Hermann

km

3 / a

Sediment

Water0 50 million t/a

Adapted from Parker, 1988, IAHS Pub. 174

Hermann

Omaha

Milh

ões

t/a

Water year in the northern hemisphere

Other causes

Decline = - 23 million tons y-1

R2 = 0.52

Decline = - 3.3 million tons y-1

R2 = 0.47

0

200

400

600

800

1000

1930 1950 1970 1990 2010

Year

An

nu

al s

usp

end

ed-s

edim

ent

dis

char

ge,

m

illi

on

to

ns

Cu

mu

lati

ve R

evet

men

t o

r D

ike

Co

nst

ruct

ion

,km

0

400

300

200

100

An

nu

al s

usp

end

ed-s

edim

ent

dis

char

ge, m

illio

n m

etri

c to

ns

Cu

mu

lati

ve p

rote

ctio

n o

f th

e b

ank

or

cum

ula

tive

con

stru

ctio

n o

f d

ikes

, k

ilom

eter

s

Bank protection

dikes

year

~ 150 million t/a~ ??? million t/a

Other causes

Soil conservationUSDA Photo: Tim McCabe

~ 150 million t/a~ ??? million t/a~ ??? million t/a

Area, ha

Many small reservation in catchment of the

Missouri River

Effect: Change in the C-Q relation

Tarbert Landing

0

200

400

600

800

1000

200 300 400 500 600 700

Discharge, km3 y-1

Me

an

an

nu

al

su

sp

en

de

d-s

ed

ime

nt

co

nc

en

tra

tio

n,

mg

L-1

1950-1966

1967- 2007

C

Mea

n a

nn

ual

con

cen

trat

ion

of

susp

ende

d se

dim

ent,

mg

/ L

Q, Water discharge, km3 / a

Transport-limited system

Supply-limited system

~ 150 million t/a~ ??? million t/a~ ??? million t/a

Our Conclusions and ThoughtsOur Conclusions and Thoughts

1.1. Some of the missing sediment is behind Some of the missing sediment is behind the large dams. the large dams.

2.2. Structures like dikes and “Structures like dikes and “wing damswing dams”, ”, designed to protect banks store sediment designed to protect banks store sediment and prevent erosion of the sediment.and prevent erosion of the sediment.

3.3. Soil conservation probable has bee Soil conservation probable has bee effective in reducing the sediment effective in reducing the sediment discharge to the Missouri-Mississippi discharge to the Missouri-Mississippi River system.River system.

4. The 4. The Missouri-MississippiMissouri-Mississippi system has changed from transport system has changed from transport limited system to a supply-limited system. limited system to a supply-limited system.

5. Sediment deposition can be a problem 5. Sediment deposition can be a problem and sediment deposition can be and sediment deposition can be beneficial depending upon the human beneficial depending upon the human assessment of the situation..assessment of the situation..

6. We need to continue to collect good data 6. We need to continue to collect good data on sediment discharge. on sediment discharge.

Good data lives forever and are Good data lives forever and are fundament to modeling sediment fundament to modeling sediment transport. transport.

Models should only be used to synthesize the data. Models should only be used to synthesize the data.

In the world of “non-stationary”, continuity of data is critical. In the world of “non-stationary”, continuity of data is critical.

Our Conclusions and ThoughtsOur Conclusions and Thoughts

7.7. The scientific paper in press on this The scientific paper in press on this subject could not have been possible subject could not have been possible without data collected over a long without data collected over a long period of time (decades)period of time (decades)

8.8. We need to understand river We need to understand river ecosystems completely and not only in ecosystems completely and not only in terms of engineering structures. terms of engineering structures.

Our Conclusions and ThoughtsOur Conclusions and Thoughts

9. “Lean by listening and 9. “Lean by listening and observing the river—observing the river—each river is each river is different.”.different.”.

Our Conclusions and ThoughtsOur Conclusions and Thoughts

Obrigado por sua atenção.Obrigado por sua atenção.

Questões?Questões?