1. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville Fluvial Geomorphology Keil J. Neff, Ph.D. University of Tennessee Department of Civil and Environmental Engineering Water Resources

2. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 2 Fluvial Geomorphology Defined The study of valley and channel landform development as influenced by moving water such as rivers and streams. Changes in the independent variables of discharge, sediment load supplied to reach, and valley slope give rise to adjustments in the dependent variables of sediment load and particle size, hydraulic characteristics, and morphologies, all of which interact with each other. http://ak.water.usgs.gov

3. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 3 Watersheds and Hydrologic Cycle Terms: watershed, tributary, headwaters, mouth Image courtesy of FISRWG

4. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 4 4 Spatial Scale Frissell et al (1996)

5. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 5 Knighton, 1998 Channel Geometry Controls

6. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 6 Functional Characteristics Stream bed: channel bottom of a stream, river or creek; the physical confine of the normal water flow Stream bank: lateral confines or channel margins, during all but flood stage Flood plain: flat or nearly flat land adjacent to a stream or river that experiences occasional or periodic flooding Riparian corridor: interface between land and a stream: vegetated area above stream bank which provides canopy cover and partially protect a stream from the impact of adjacent land uses

7. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 7 In-stream Features Terms: Pool - water depth is above average and the stream velocity is below average Riffle - current is above the average stream velocity and where the water forms small rippled waves as a result Glide/Run - section of a stream with a relatively high velocity and with little or no turbulence on the surface of the water In-stream cover - areas of shelter in a stream channel that provide aquatic organisms protection from predators or competitors and/or a place in which to rest and conserve energy due to a reduction in the force of the current

8. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 8 8 Pool-Riffle Sequence Riffle-Pool Sequence: The development of alternating deeps (pools) and shallows (riffles) is characteristic of both straight and meandering channels with heterogeneous bed materials, containing gravel, in the size range of 2 to 256 mm. In general, riffle-pool sequences occur with bed slopes 5%.

9. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 9 Point Bars and Cutbacks A point bar is a depositional feature of streams. Point bars are found in abundance in mature or meandering streams. They are crescent-shaped and located on the inside of a stream bend

10. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 10 Channel Pattern: Sinuosity Sinuosity = Channel length / Valley length

11. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 11 Rosgen Stream Types Rosgen 1996 Terms: braided, sinuosity, slope

12. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 12 Rosgen Stream Classification Rosgen (1996) System of Stream Classification Based on: 1. slope 2. sinuosity 3. W/D ratio 4. entrenchment 5. bed sediment Rosgen 1996

13. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 13 Stream Stability Balance Resistive ForcesErosive Forces Channel and Bank Stability The dominant controls of channel form adjustment include discharge and sediment load (notably bed material load). Lane’s Law stable channel balance: Qs·ds= Q · S Hey (1992)adds bank sediment and vegetation to the above set of independent variables (dominant controls). Qs = Sediment load Ds = Sediment size Q = Water discharge S = Slope

14. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 14 Effective Discharge Stormflows in the ~1.3-year to 1.7-year recurrence interval range have the most effect on channel erosion (Dunne and Leopold, 1978). The flow rate at which the maximum channel forming work is performed is called the “effective discharge” (Wolman and Miller, 1960).

15. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 15 Sediment Sources Channel ErosionUpland Erosion

16. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 16 Fluvial Processes Mechanics of Flow (Hydraulics) –Velocity profiles and flow resistance Sediment Transport –Thresholds of erosion –Initiation of motion –Transport processes (bedload, suspended load, wash load) Bank Erosion –part fluvial, part geotechnical Sediment Deposition Velocity and Shear Profiles

17. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 17 Channel Roughness Elements hydraulic grade control bank stabilization from concrete, rocks to trees …..

18. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 18 Deposition/Erosion Aggradation –Deposition of sediment on the stream bed –Excessive bedload input –Increase stream bed elevation Degradation –Erosion of sediment from the stream bed –Generally follows a sharp reduction in the amount of sediment entering the stream –Decrease in stream bed elevation Represent disequilibrium conditions: modifications in watershed impact bed elevation and slope, and bedload.

19. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 19 Channel and Bank Stability: Channel Evolution Model Simon 1995

20. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 20 Environmental Flows Environmental Flows refer to the regulated-flow management of water resources for multiple uses, balancing the uses for human basic needs and economies (e.g., clean drinking water, flood mitigation, food and industrial production, and recreational opportunities), and sustaining aquatic ecosystems. NEPAL GRSM

21. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 21 Disturbance: Environmental Impacts Disturbance is an interruption of “normal” ecosystem processes resulting in a change in the community of species. This can result from fluvial, chemical, geomorphic instabilities in the system. Anthropogenic Impacts to the Environment: –Watershed land use changes (e.g., urbanization, deforestation) –Channelization of River and Streams; Dams; Canals –Habitat loss or modification; Introduction of exotic species –Agricultural, Forestry, and Mining practices –Climatic change; Water withdrawals; Pollutant Discharges –Over exploitation of fish and wildlife Northbrook Restoration Project, W. North Branch of Chicago River; Northbrook, IL Chicago, Schwartz, 2002.

22. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 22 Causes of Stream Impairment - Bank Erosion - Bank Failure - Sediment Deposition - Channelization - Habitat Loss - Riparian Loss - Unsustainable Environmental Flows - Water Quality Impairment - Ecological Condition Dysfunction - Loss of Biotic Interactions Twin Creek, OK Wilson, 2008.

23. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 23 Post-Developed Pre-Developed Decreased Baseflow Increased Runoff Volume Increased Peak Flowrate Runoff Rate Time Gradual Recession and Good Baseflow Urbanization Impacts On Hydrology Increased imperviousness and loss of watershed storage leading to increased flow volumes, peaks and durations Channel straightening and armoring, road crossings

24. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 24 Stream Channelization

25. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 25 Channel and Bank Stability in Urbanizing Watersheds Beaver Creek, Knox Co. TN Increased Suspended Sediment (TSS)

26. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 26 Water Quality Nonpoint source (NPS) pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water. These pollutants include: Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas Oil, grease, and toxic chemicals from urban runoff and energy production Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks Salt from irrigation practices and acid drainage from abandoned mines Bacteria and nutrients from livestock, pet wastes, and faulty septic systems

27. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 27 Over 5,500 stream miles are listed for sedimentation/habitat alteration in Tennessee

28. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 28 Urbanization Impacts to Lotic Habitats Deposition of fine sediment Destruction of habitat structure (pool riffle sequence) Fish loss due to reduced baseflows Loss of hydraulic refugia due to reduced baseflow Loss of habitat connectivity Increased temperatures Increased pollutant loading

29. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 29 Process Framework for Stream Habitat Relationships between hydro-geomorphic systems and physical stream habitat; in addition to in- stream flows and water quality.

30. AmeriCorps Water Quality Team Training - Geomorphology, 29 August 2011, Knoxville 30 Questions Keil J. Neff kjn.water@gmail.com