Detroit District Sediment and River Features...US Army Corps of Engineers Detroit District From FISRWG, 1998 and Schumm, 1977 Sediment Delivery Sediment Delivery is driven by Gravity

Sediment and River Features

Where does sediment come from?

Why do we care about sediment?

Overview of river features

US Army Corps of Engineers

Detroit District

Great Lakes Hydraulics and Hydrology Office


Detroit District

Sediment Sources

• River Bank Erosion

• Overland Runoff Erosion

Source: Iowa State Extension

Source: Geograph.org.uk


Detroit District

From U. of Nebraska-Lincoln, 2008

Overland Runoff Erosion Detachment


Detroit District

On mild slopes, raindrop impact is the dominant mode of displacement.

As slope increases, detachment due to overland flow increases.


Detroit District

Soil Erodibility

Texture and Particle Size Affect Erodibility

• Silt is most easily eroded component. Loess sediments are

particularly susceptible. (0.004mm - 0.062mm)

• Clays are cohesive and tend to remain bound to the soil

structure; however, once detached they remain in in suspension

(<0.004mm)

• Sand is relatively large and difficult to entrain. Sand also

promotes infiltration (0.062mm - 2mm)

• Organic matter increases infiltration and builds soil structure

(blocky or platy nature)


Detroit District

Factors Affecting Soil Loss

Rainfall – intensity, duration and energy

Soil Erodibility – texture, structure, organic matter content

Topography – slope length and steepness

Surface Condition – bare soil, vegetated, mulched

Erosion Control Practices – sediment basin, silt fences, terracing,

contour planting

Source: Michigan State University, IWR

ErosivityyErodibilitErosionBank

Lateral

Movement of

bank.

Measured in

feet/year

Resisting Force

Intrinsic property

of bank.

Function of:

Soil

Vegetation

Bank Angle

Etc.

Eroding Force

Property of the

hydraulics.

Function of:

Near Bank Shear

Stress

Stream Bank Erosion


Detroit District

Stream Bank Erosion

Source: Rosgen 1996


Detroit District

Activities that produce sediment

1. Landuse

Agriculture

Forest Management (logging)

Urban and Construction

2. Channel Incision/erosion

3. Dam Removal


Detroit District

Agricultural Sediments

• Bare soil is biggest producer

• Spring is critical time due to:

Degraded crop residue

Recent tillage

Lack of crop canopy


Detroit District

Forest Sediments

• Very low sediment yield in closed forest

• Sediment sources are:

Logging roads

ATV trails

Flashier hydrograph (bank erosion)

Bare soil due to logging activities


Detroit District

Urban Sediments

• Urbanization armors the watershed and reduces the

sediment production from upland sources

• Increases peak flows, accelerating bank and bed

erosion

Source: Selegean, USACE


Detroit District

Dam Removal Sediments

• Dams contain impounded sediment

• If not removed wisely, they can be a major source of

sediment


Detroit District

Dam Removal Sediments Reservoir Drawn Down Slowly



Detroit District

Dam Removal Sediments Profile Readjustment



Detroit District

Land Uses and Erosion

75

7.50.4 0.04

0

10

20

30

40

50

60

70

80

Soil Loss

(tons/acre/

yr)

Con

stru

ctio

n

Row

Cro

p

Gra

ss

Fores

t

Source EPA, 1973


Detroit District

From FISRWG, 1998 and Schumm, 1977

Sediment Delivery

Sediment Delivery is driven

by Gravity

• Just like water, sediment

will flow downhill until

deposited into the Great

Lakes

• Sediment sitting at a

higher elevation than the

lakes has potential energy

stored in it

• The higher the change in

elevation, the greater the

energy stored in each

particle.


Detroit District

Sediment Delivery

Flat Field

Little or no potential to move sediment from

field to stream

Field Stream


Detroit District

Sediment Delivery

Mild Sloped Field

Sediment begins moving off field into stream

Field Stream


Detroit District

Sediment Delivery

Steep Hill Slopes

Sediment rapidly moves off field into stream

Hill Slope Stream


Detroit District

Sediment Delivery Slope Matters


Detroit District

Great Lakes Relief

Around the Great

Lakes, there is little

topographic relief to

drive sediment delivery

…but that wasn’t always the case

Source: Ray Sterner, Johns Hopkins University


Detroit District

Historic Relief in Michigan

From Dorr and Eschman, 1970

Penokean orogeny build this range during Middle

Precambrian (1640 million years ago). This range has long

since eroded away.


Detroit District

Mountain Building – high sediment yield

Mountains Eroding –

moderate sediment yield

Mountains gone – Low relief, low sediment yield

Erosion Cycle

Drawings from Dorr and Eschman, 1970


Detroit District

Source: National Geographic


Detroit District

Appalachian Orogeny and the Death of

Hexagonoria

Hexagonoria percarinata

Source: Dorr and Eschman, 1970

Source: Dorr and Eschman, 1970

Devonian Great Lakes

(~350 Mybp)

http://www.pbase.com/qjul73/michigan


Detroit District

Appalachian Orogeny and the Death of

Hexagonoria

350 mya

From King, 1977

Sediment – The Good and the Bad

All erosion is NOT bad! Without erosion, we would not

have:

Pools for the big fish to hide in

Overhanging trees to shade the stream and provide refuge

Scoured material to build riffles with

Erosion can be natural – Grand Canyon!

Erosion becomes a problem when:

we build our infrastructure too close to the stream

we cause is to accelerate through our management of the

water and sediment supplies

Reduced visibility

Damage to fish gills

Infilling of habitat

Reduction in food supply

Increase temperature

* This slide was adapted from the website of Canada’s Department of Fisheries & Oceans

Sediment – The Good and the Bad Sediment Impact on Fish Habitat

Sediment – The Good and the Bad

Stream “Stability”

Definition of Stability: The tendency of a stream to

maintain its cross-section, planform and profile

geometry over time, effectively transporting its water

and sediment supply without aggrading (building up),

degrading (down-cutting)

Erosion occurs in a Stable stream


Detroit District

Stream Stability Lane’s Diagram

Source: Rosgen, 1996

There is only a thin veneer of “living”, organic soil

in most places on Earth

It takes 500-1,000 years to form 1 inch of soil

We are losing soil faster than it is being produced

Sediment – The Good and the Bad Soils are Non-Renewable

Sediment – The Good and the Bad Aggradation on Whittlesey Cr

Sediment – The Good and the Bad Exposed Infrastructure

Sediment – The Good and the Bad Aggradation Increases Flooding

Source: USACE - ERDC


Detroit District

Sediment moves slowly and episodically The sediment train

• add figure

•

Tillage relocates sediment

Sediment trapped in buffer strips Sediment Stored in point bar

Sediment starts here

Storm mobilizes sediment

10-yr flood deposits sediment on floodplain



Sediment Stored in mid-channel bar

Source: Microsoft Live Maps


Detroit District

Sediment moves slowly and episodically St. Joseph River – Normal Flow


Detroit District

Sediment moves slowly and episodically St. Joseph River – 2-yr Flow


Detroit District

Sediment moves slowly and episodically St. Joseph River – 5-yr Flow


Detroit District

Sediment and High Flows

Most sediment moves during the largest few flow events

each year

Year

Model Conditions

Total Soil Erosion in

the Watershed

(m3 per year)

Total Sediment at

Harbor Mouth

(m3 per year)

1830

Pre-Development

55,000

21,000

1992

Reference Condition

676,000

44,000

Historic Sediment Supplies St. Joseph River


Detroit District

Stream Features

Source: North Carolina Sea Grant

Source: West Virginia DEP


Detroit District

Stream Features

Source: Michigan Stream Team


Detroit District

Stream Features

Riffles – Steep and shallow; poorly defined thalweg (deepest spot across);

riffles control the flow in a stream (hydraulic choke point); usually found in

straight reaches; this is where your canoe usually rubs bottom.


Detroit District

Stream Features

Pools – Deepest spot along a reach; Water-surface is nearly

flat; Often has large bed material at the bottom; often located at

the outside of meander bends

Source: EPA


Detroit District

Stream Features

Runs – Steep, but much deeper than riffles (steep and deep);

usually have a well defined thalweg; it is said that water “runs”

smooth through a run (as opposed to with ripples in the riffle);

smaller fish are often found here since they can’t yet compete

for the pools.


Detroit District

Stream Features

Glides – Located immediately downstream of the pool; Adverse

bed slope; water has to accelerate to get “uphill” often resulting

in gravel beds free of fine material (spawning beds)

Source: Rosgen


Detroit District

Stream Features

You run into a pool and glide out.


Detroit District

What Moves Sediment?

Shear Stress

τ = γ•s•d

Shear Stress = Unit wt water x slope x depth

Velocity Profile

No Friction With Friction

Pool

Riffle

Riffle

d=high

Slope = very low

Low Flow

Shear Stress

(Sediment Transport)

Low-Moderate

Shear Stress


Very Low

τ = γ•s•d

Pool

Riffle

Riffle

d = very high

d = moderate

Shear Stress


High

Shear Stress


Very High

τ = γ•s•d

High (bankfull) Flow

Pool

Riffle

Riffle

d=high

Receding Flow

Shear Stress


Moderate

Shear Stress


High

τ = γ•s•d

Pool

Riffle

Riffle

d=high

Slope = very low

Low Flow

Shear Stress


Low-Moderate

Shear Stress


Very Low

τ = γ•s•d

Pool

Riffle

Riffle

d=high

Slope = very low

Low Flow

Shear Stress


Low-Moderate

Shear Stress


Very Low

τ = γ•s•d

Sediment in storage

Pool

Riffle

Riffle d = very high

d = moderate

Shear Stress


High

Shear Stress


Very High

τ = γ•s•d


Sediment in

transport

Pool

Riffle

Riffle

d=high

Receding Flow

Shear Stress


Moderate

Shear Stress


High

τ = γ•s•d

Sediment in

storage

Sediment in

transport

Pool

Riffle

Riffle

d=high

Slope = very low

Low Flow

Shear Stress


Low-Moderate

Shear Stress


Very Low

τ = γ•s•d

Sediment in storage

Questions?


Detroit District

Pool

Riffle

Riffle Slope = very low

Low Flow

Shear Stress


Low-Moderate

Shear Stress


Very Low

Bedload and Suspended Load

Pool

Riffle

Riffle

Shear Stress


High

Shear Stress


Very High

τ = γ•s•d


Bedload and Suspended Load

Pool

Riffle

Riffle

d=high

Receding Flow

Shear Stress


Moderate

Shear Stress


High

τ = γ•s•d

Documents

Detroit District Sediment and River Features...US Army Corps of Engineers Detroit District From FISRWG, 1998 and Schumm, 1977 Sediment Delivery Sediment Delivery is driven by Gravity