Interactions class Getting and understanding watershed flux data Influence of Large Woody Debris (LWD) on rivers Influence of Hillslope materials and processes on rivers Influence of the Atmosphere on rivers, 1927 flood example

Sediment Transport Through Rivers 1 Sediment Transport Through Rivers Bedload -- material moving along the bed, shear forces exerted by water sufficient to move clasts -- rarely measured (at % level) Suspended Load -- material kept in the water column by turbulence and lift forces (easy to measure in grab samples) Dissolved Load -- material in solution (easy to measure in grab samples) Bedload usually <<< than suspended load and ignored Dissolved load varies, usually < than suspended load

Sampling for suspended load……. 1 Sampling for suspended load…….

Mass Loadings and Erosion Rate Estimation 1 Mass Loadings and Erosion Rate Estimation Integrate suspended load over all flows (mass/time) + Integrate bedload load over all flows (mass/time) + Integrate dissolved load over all flows (mass/time)

Dissolved load varies over time and discharge 1 Dissolved load varies over time and discharge

USGS Water Quality Data on line Dissolved and Suspended Load 1 USGS Water Quality Data on line Dissolved and Suspended Load http://nwis.waterdata.usgs.gov/nwis/qwdata?site_no=04282815&agency_cd=USGS&begin_date=&end_date=&format=html_table&inventory_output=0&rdb_inventory_output=file&date_format=YYYY-MM-DD&rdb_compression=file&qw_sample_wide=0&submitted_form=brief_list

m3 = 100 cm* 100 cm* 100 cm = 106 cm3 =103 liters Data Manipulation Data supplied in mg/l (1/1000 g per 1000 g) or ppm Need to sum all constituents (Ca, Na, Mg, Cl, C03) Need to know daily flow (in liters). How many liters/m3? Multiply concentration by flow  Ca Na Mg Flow 15 mg/l 8 mg/l 3 mg/l 4 mg/l 0.1 m3/s m3 = 100 cm* 100 cm* 100 cm = 106 cm3 =103 liters 100 l/s* 60s/min*60min/hr*24hr/day*15mg/l*0.000001kg/mg= 129.6 kg/day dissolved load

1 TO GET YEARLY LOAD Integration over all flows is a non trivial problem! Need Rating Curves (suspended, dissolved, bedload) Suspended Load Note Scatter Hysteresis loop

Other Approaches…Reservoir trapping (may miss dissolved) 1 Other Approaches…Reservoir trapping (may miss dissolved) Nahal Yael, Negev Desert

SEDIMENT YIELD = what comes out 1 SEDIMENT YIELD = what comes out = or ≠ Timescale Steady state Human impact Episodic disturbance SEDIMENT GENERATION = Material generated by erosion

1 Trimblegram

Importance of Vegetation 2 Importance of Vegetation Bank Stabilization, effective soil cohesion Source, Large Woody Debris

Queets River, Olympic Penninusla, Washington 2 Large Woody Debris

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2 Queets -- Meander Jam

Most rivers have been de-snagged 2 Montgomery et al., 2003 Putget Lowland

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Reach Scale Effects 2

In-Channel Effects 2

Valley Bottom Effects - Wood adds Complexity 2 Valley Bottom Effects - Wood adds Complexity Nisqually River w/wood Floodplain Elevation (m)

Effects Felt Downstream 2

2 Briaded Rivers Weak banks High sediment load Flashy

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Influence of Hillslope Materials and Processes on Channels 3 Slides are frequent in mountain environments Example: Chris Brummer, Squire Creek, North Cascades, Slide into Channel

3 Toe of Slide - QT VR

Sediment and Woody Debris Supply - pulsed delivery 3 Sediment and Woody Debris Supply - pulsed delivery

Stepping of Channel Profile Damming of ephemeral lakes by slides 3 Outlet, overtopping dam

3 Help set channel roughness boulders may be delivered by older slides….or underlying bedrock or till

Here, stratigraphic evidence this is not the first slide… 3 Here, stratigraphic evidence this is not the first slide… Recent Slide Debris Older Slide Debris

4 1927 Flood Antecedence --Rainfall during the month of October averaged about 150 percent of normal across the state. In northern and central sections, some stations received 200-300 percent of normal.

Major Channel Change and Realignment - Proctor 4

Major damage at constrictions, e.g., bridges 4 Isohyet map

Winooski-Burlington response 4 Winooski-Burlington response

4 Cause of the 1927 Flood Mositure-laden air was forced to rise as it encountered the Green Mountains, resulting in torrential downpours. Rainfall in Northfield totaled 1.65 inches from 4:00 am to 11:00 am on the 3rd, with 4.24 inches falling from 11:00 am to 8:00 pm. The total from late evening of the 2nd to late morning on the 4th was 8.71 inches.

Wednesday Lab Meet in classroom Move to the field, Bolton Cooler weather, be prepared. Wear sturdy shoes please