Rc101 Day 1 Jennings 10

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  • 1. Stream Morphology Assessment
    Greg Jennings, PhD, PE
    Professor, Biological & Agricultural Engineering
    North Carolina State University
    jennings@ncsu.edu
    Barbara Doll, PE
    Jan Patterson, PE
    Jason Zink, PE
    Zan Price, PE
    Kris Bass, PE
    Justin Church, PE
    Mike Geenen, EI
    Mike Shaffer, EI
    Karen Hall
    Dave Penrose
  • 2. Why Restoration?
    • Water quality impairments
    • 3. Habitat loss
    • 4. Ecosystem degradation
    • 5. Land loss
    • 6. Safety concerns
    • 7. Infrastructure damage
    • 8. Flooding
    • 9. Aesthetics
  • Stream Insults
    • Straightening & dredging
    • 10. Floodplain filling
    • 11. Watershed manipulation
    • 12. Sedimentation & stormwater
    • 13. Pollution discharges
    • 14. Utilities & culverts
    • 15. Buffer removal
    • 16. Disdain & neglect
  • Stream Impairment Causes (US EPA)
    Pathogens
    Sediment
    Nutrients
    Habitat Alterations
    Organic Enrichment
    Metals
    PCBs
    Temperature
    Flow Alterations
    Mercury
  • 17. Restoration Components
    • Channel morphology & floodplain connection
    • 18. In-stream structures
    • 19. Streambank bioengineering
    • 20. Riparian buffers & habitat enhancements
    • 21. Stream crossings
    • 22. Stormwater/watershed management
    • 23. Monitoring & maintenance
    • 24. Public access & education
  • Stream Morphology Assessment
    Fluvial Processes & Forms
    Streams & Watersheds
    Stream Ecosystems
    Stream Morphology
    Stream Classification
    Assessment of Condition
  • 25. Fluvial Processes and Landforms
    How do stream systems work?
    What determines stream size & shape (i.e. morphology)?
  • 26. Fluvial Geomorphology:
    study of landforms and the fluvial processes that shape them
  • 27. Fluvial Processes:
    associated with flowing water, including sediment erosion, transport, and deposition
  • 28. Hydrologic Cycle
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 29. Fluvial Forms
  • What is a Stream?
    … a body of water with a current, confined within a bed and streambanks
    Synonyms:  bayou, beck, branch, brook, burn, creek, crick, kill, lick, rill, river, rivulet, run, slough, syke
    Streams are conduits in the water cycle and also important habitats
    Photo Credit: Eve Brantley, Auburn University
  • 45. Watershed
  • 46. Watershed:
    “Area of land that drains water, sediment, and dissolved materials to a common outlet at some point along a stream channel”
    Dunne and Leopold, 1978
    Watershed form is influenced by:
    Climate
    Geology & Soils
    Fluvial Geomorphology
    Vegetation
    Land Uses
  • 47. From Webster's Revised Unabridged Dictionary (1913) :
    Watershed, n [Cf. G. wasserscheide; wasserwater + scheidea place where two things separate, fr. scheidento separate.]
    The whole region or extent of country which contributes to the supply of a river or lake.
    The line of division between two adjacent rivers or lakes with respect to the flow of water by natural channels into them; the natural boundary of a basin.
    Other Terms: Catchment, Drainage basin, River basin
  • 48. North Carolina River Basins
  • 49. Watershed Functions:
    Transport & Storage:
    Water
    Sediment
    Dissolved Materials
    Habitat:
    Animals
    Plants
    Humans
  • 50. Water Transport & Storage
    Hydrology: The study of the flow of the earth’s waters through the hydrologic cycle
    Hydrograph: Displays change in flow (discharge over time
    Peak Flow
    Rising Limb
    Falling Limb
    Mean Daily Flow
    www.Geology.com
  • 51. Precipitation
    Runoff
    Infiltration
    Evapotranspiration
  • 52.
  • 53. Extreme Weather!
  • 54. Water Transport to Streams
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 55. Land use in a watershed affects:- water quality- water quantity- ecosystem services
  • 56. Watershed Stream Network
    Neuse River Basin, NC
  • 57. Strahler Stream Order
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 58. USGS Topographic Map – 1:24,000 scale
    Courtesy of John Dorney and Perianne Russell, NC Division of Water Quality
  • 59. How to determine stream origins?h2o.enr.state.nc.us/ncwetlands
  • 60.
  • 61. Contributing Drainage Areas for Stream Origins(Ephemeral to Intermittent/Perennial)
    Courtesy of John Dorney and Perianne Russell, NC Division of Water Quality
  • 62. Problems with Contiguous USGS Maps
    Headwater stream shown on one map and not the other
    Tributaries shown on one map and not the other
    McDaniel Bald and Marble Quadrangles, Cherokee County, NC
    Courtesy of John Dorney and Perianne Russell, NC Division of Water Quality
  • 63. Groundwater Influences Streamflow
    Losing Stream Gaining Stream
    Groundwater Recharge Groundwater Discharge
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 64. Ephemeral
    Intermittent
    Perennial
  • 65. Stream: A system of fluvial forms & habitats
    Photo Credit: Eve Brantley, Auburn University
  • 70. Streams are ecosystems
    • Communities of organisms and their physical, chemical, and biological environments
    Courtesy of Francois Birgand, NCSU
  • 71. Ecosystem Services
    • Provisioning – food, energy, industry
    • 72. Regulating – climate, waste, nutrients
    • 73. Supporting – water quality, pest control
    • 74. Cultural – recreation, inspiration
    • 75. Preserving – species diversity
  • Self-Design
    The reorganization, substitution and shifting of an ecosystem (dynamics and functional processes) whereby it adapts to the environment superimposed upon it. (Mitsch & Jorgensen, Ecological Engineering)
  • 76. Fish Biodiversity
    41
    185
    150
    195
    41
    250
    32
    236
    792
    154
  • 77. River Continuum Concept
    Connections
    • Watershed to Corridor to Stream
    • 78. Biological communities upstream and downstream
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 79. Field Investigations
    What is living in the stream?
    What are the physical and chemical conditions of the stream?
  • 80. Food Web
  • 81. Stream Ecosystems
    Mostly downstream fluxes of energy and matter
    Lateral and vertical connections to the riparian and hyporheic zones
    Courtesy of Francois Birgand, NCSU
  • 82. Hyporheic Zone
  • 83. Stream Functions
    Transport water
    Transport sediment
    Habitat (aquatic & terrestrial)
    Recreation & aesthetics
    Safe Water Supply
  • 84. Stream Corridor Longitudinal Profile
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 85. Sediment Transport
    Flowing water does work:
    • Erosion
    • 86. Transportation
    • 87. Deposition (of alluvium)
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 88. Erosion: Detachment of material from bed and banks
    95% of stream energy used to overcome friction
    Remaining energy used for Erosion Processes:
    • Flowing water dissolves materials
    • 89. Hydraulic action dislodges materials
    • 90. Abrasion of heavy materials rolling on bottom
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 91. Transportation: Movement of material by water
    Stream Load includes:
    dissolved + suspended + bed load
    Capacity: maximum load that can be transported for a given discharge (increases with velocity and turbulence)
    Competence: largest size material that can be transported for a given discharge
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 92. Bedload is related to Discharge for Each River
  • 93. Deposition:
    Aggradation: Raising the bed elevation
    Bars: Depositional areas that may change flow directions
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 94. Bed Material (Substrate)
    Silt/Clay: < 0.062 mm
    Sand: 0.062 – 2 mm
    Gravel: 2 – 64 mm
    Cobble: 64 – 256 mm
    Boulder: 256 – 2048 mm
  • 95. Substrate CharacterizationWolman Pebble Count
  • 96. High Slope Moderate Slope Low Slope
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 97. Sediment Deposition:
  • Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 102. Point Bars:
    Inside meander bends
  • 103. Lateral Bars:
    Formed in straight channels
  • 104. Lateral Bars:
    Formed in straight channels
  • 105. Mid-channel Bars:
    Formed in over-wide channels
  • 106. Transverse Bars:
    Formed in straight channels
  • 107. Meandering Stream: Alluvial Forms
    Flow Downstream
    Floodplain
    Scarp
    Bankfull Stage
    Point Bar
    Pool
    Left Bank
    Right Bank
    Riffle
    Thalweg
  • 108. Bankfull Stage
    “corresponds to the discharge at which channel maintenance is the most effective, that is, the discharge at which moving sediment, forming or removing bars, forming or changing bends and meanders, and generally doing work results in the average morphologic characteristics” (Dunne and Leopold,1978)
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 109. Bankfull
  • 110. Channel Evolution (incision)
  • 111. Terrace
    Bankfull
  • 112. Incised System: Floodplain Creation
    Terrace
    Floodplain
  • 113. Stream Morphology:size and shape of channel & floodplain (dimension, pattern, profile)
  • 114.
  • 115. Valley type affects stream morphology
    Colluvium is loose sediment transported by gravity and deposited at the bottom of a slope.
    Alluvium is sediment deposited by a river in the channel or floodplain
    Alluvial valleys occur where sediment particles are dropped by slow-moving water.
  • 116. Valley Types: (www.epa.gov/watertrain/stream_class)
    Valley Type II Moderately steep, gentle sloping side slopes often in colluvial valleys
    From EPA Watershed Academy: Fundamentals of the Rosgen Stream Classification System
  • 117. Valley Types: (www.epa.gov/watertrain/stream_class)
    Valley Type VIII Wide, gentle valley slope with well-developed floodplain adjacent to river terraces
    From EPA Watershed Academy: Fundamentals of the Rosgen Stream Classification System
  • 118. Stream Corridor Lateral Profile
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 119. Floodplains: Critical Stream Components
  • 120. Floodplain Functions
  • 127. Terrace
    Floodplain
    Left Bank
    Right Bank
    Thalweg
    Streambed
    Downstream
  • 128. Terrace
    Floodplain
    Right Bank
    Left Bank
    Thalweg
    Streambed
    Downstream
  • 129. Pool Cross-Section (Meandering Stream)
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 130. Cross-Section of Channel and Floodplain
  • 131. Pattern (plan form)
    Alluvial (low-gradient) streams naturally meander across a valley with a somewhat predictable pattern
  • 132. Alluvial River Processes
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 133. Sellin and Willetts, Floodplain Processes, Walling, 1996
  • 134. Oxbow Formation in Meandering Streams
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 135. Chute cutoff across tight meander bend
  • 136. Oxbows
  • 137. Oxbows
  • 138. Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 139. Meandering Stream: Alluvial Forms
    Riffle
    Point Bar (deposition)
    Run
    Glide
    Pool
  • 140. Stream Bedform Variability:Slope Substrate size Velocity OxygenationShear stress Habitats
  • 141. Profile (bed form)
    Water Surface
    Riffle Slope
    Run Slope
    Glide Slope
    Pool Slope
    Thalweg
    Pool Spacing
  • 142. Riffles
  • Importance of Riffles
    Areas of oxygenation
    Highly diverse substrate and habitat
    Diverse macroinvertebrate population
  • 147. Pools
  • Importance of Pools
    Refuge for fish during low flow, drought periods
    Rest stop and food area for fish
    Predator refuge for young fish
  • 152. River Dimensions
  • 153. Velocities:Low flow and Flood flow
    Little Garvin Creek, Clemson, SC
  • 154. Channel dimensions in a meandering stream
    www.uwsp.edu/gEo/faculty/lemke/geomorphology/lecture_outlines/04_fluvial_landforms.html
  • 155. Profile is related to Pattern
  • 156. Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 157. Step Pool Streams
    (high gradient)
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 158. Grade Controls
    Nickpoints
  • 159. Flow diversity improves habitat:
  • Diversity of habitats
  • 162. Stream Habitats
    Macrohabitats: riffles, runs, pools, glides, steps, side channels
    Microhabitats: roots, leaf packs, wood, rocks, plants, hyporheic zone
  • 163. What habitats do you see?
    Pool
    Leaf Pack
    Wood
    Rocks
    Roots
    Riffle
  • 164. What habitats do you see?
    Roots
    Wood
    Pool
    Leaf Pack
    Riffle
    Rocks
  • 165. What habitats do you see?
  • 166. Natural Stream Channel Stability
    (from Leopold)
    River has a stable dimension, pattern and profile
    Maintains channel features (riffles, pools, steps)
    Does not aggrade (fills) or degrade (erodes)
  • 167. Equilibrium Controlling Variables
    Leopold et al (1964)
  • 175. Velocity & Discharge
    Q = VA = Discharge (cfs)
    V = Velocity (ft/s)
    A = Cross-Section Area (ft2)
    V related to slope, channel shape, and channel roughness
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 176. Manning Formula
  • 177.
  • 178. A = 40 sq ft
    W = 22 ft
    R = 1.7 ft
    S = 0.010 ft/ft
    n = 0.040
    V = 5.0 ft/s
    Q = 200 cfs
    A = 220 sq ft
    W = 55 ft
    R = 3.5 ft
    S = 0.004 ft/ft
    n = 0.035
    V = 6.1 ft/s
    Q = 1350 cfs
  • 179. Sediment Transport
    Flowing water does work:
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 182. Velocity & Particle Size Determine Process
    V = 5 ft/s
    V = 1 ft/s
    http://www.uwsp.edu/gEo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html
  • 183. Stream Competence (www.epa.gov/WARSSS)
  • 184. Shear Stress: fluid force per unit area acting on the streambed
     = Rs = Shear Stress (lb/ft2)
     = Unit Weight of Water = 62.4 lb/ft3
    R = Hydraulic Radius (ft) = A / P
    S = Average Water Surface Slope (ft/ft)
    A = Riffle Cross-Section Area (ft2)
    P = Wetted Perimeter (ft)
    P = Wbkf +2*Dbkf (approx)
  • 185. A = 40 sq ft
    W = 22 ft
    R = 1.7 ft
    S = 0.010 ft/ft
    • = 1.0 lb/sq ft
    Competence = ~250 mm
    A = 220 sq ft
    W = 55 ft
    R = 3.5 ft
    S = 0.004 ft/ft
    • = 0.8 lb/sq ft
    Competence = ~200 mm
  • 186. R = 1.5 ft
    S = 0.0012 ft/ft
    n = 0.038
    V = 1.8 ft/s
    Q = 89 cfs
    • = 0.11 lb/sq ft
    Competence = ~30 mm
  • 187. Channel Forming Discharges
    and Regional Curves
  • 188. Channel-forming (dominant) discharge
    Estimated using:
    • Effective discharge
    • 189. Bankfull discharge
    • 190. Discharge associated with recurrence interval (typically 1 to 2 year)
  • Effective Discharge
    Transports the most sediment over a long time
  • 191. Bankfull Discharge
    Flow fills active channel and spreads onto floodplain
    Represents break between channel & floodplain processes
    For channel in equilibrium, assumed to equal the effective discharge
    Return Period typically 1 to 2 years
  • 192. Bankfull Stage
    “corresponds to the discharge at which channel maintenance is the most effective, that is, the discharge at which moving sediment, forming or removing bars, forming or changing bends and meanders, and generally doing work results in the average morphologic characteristics” (Dunne and Leopold,1978)
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 193. Bankfull
  • 194. Bankfull Indicators
    • Top of streambank (floodplain)
    • 195. Break in slope on streambank
    • 196. Top of point bar
    Bankfull
    Bankfull
  • 197. Bankfull
  • 198. Bankfull
  • 199. Bankfull
  • 200. Bankfull
  • 201. Channel Evolution
    (Succession)
    Response to incising forces
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 202. Terrace
    Bankfull
  • 203. Bankfull
  • 204.
  • 205. Bankfull
  • 206. Bankfull
  • 207. Taking the Mystery out of Bankfull
  • 208. Predicting Stream Morphology:
    Hydraulic Geometry Relationships
  • 209.
  • 210.
  • 211. NC Coastal Plain Regional Curve
  • 212.
  • 213.
  • 214.
  • 215. Stream Morphology:size and shape of channel & floodplain (dimension, pattern, profile)
  • 216. Dimension (cross-section)
  • Dimension: Cross-Section
  • 222. Riffle Dimensions
    Wbkf
    Bankfull
    Abkf
    dbkf
    Measure Bankfull Width (Wbkf) and Bankfull Area (Abkf)
    Mean Depth, dbkf = Abkf / Wbkf
    Width to Depth Ratio, W/d = Wbkf / dbkf
  • 223. W/d = 9.3 / 1.5 = 6.2
    Wbkf
    dbkf
    Abkf
  • 224. Entrenchment Ratio
    ER = Wfpa / Wbkf
    Wfpa = Width of Flood Prone Area measured at the elevation twice bankfull max depth above thalweg
    Wbkf = Width of Bankfull Channel
    Wfpa
    Bankfull
    2 x dmax
    above thalweg
    dmax
    Wbkf
  • 225. ER = Wfpa / Wbkf = 75/ 15 = 5.0
    Wfpa
    Wbkf
  • 226. Rocky Branch Phase II Reach 2:
    Priority 2 (floodplain excavation, C channel)
    Entrenchment Ratio = Wfpa / Wbkf = 90/20 = 4.5
    Wfpa
    Wbkf
    Flood water flows onto floodplain several times each year
  • 227. Rocky Branch Phase II Reach 1:
    Priority 3 (floodplain excavation, Bc channel)
    Entrenchment Ratio = Wfpa / Wbkf = 40/20 = 2
    Wfpa
    Wbkf
  • 228. Bank Height Ratio
    BHR = dmax tob/ dmax
    dmax tob= Max Depth from top of low bank to thalweg
    dmax = Max Depth from bankfull stage to thalweg
    Bankfull
    dmax tob
    dmax
  • 229. BHR = 5.3 / 2.5 = 2.1
    Top of Bank
    Bankfull
    dmax tob
    dmax
  • 230. Pattern: Plan form
    Alluvial (low-gradient) streams naturally meander across a valley with a somewhat predictable pattern
  • 231. Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 232. Sinuosity = stream length / valley length
    K = 1850 / 980 = 1.9
    Valley Length
  • 233. Maximum Sinuosity Decreases with Slope
  • 234. Plan Form Relationships
  • 235. Meander Length Ratio = meander length / width = 78/15 = 5.2
    Meander Width Ratio = belt width / width = 57/15 = 3.8
    Radius of Curvature Ratio = radius / width = 23/15 = 1.5
    Belt Width
    Meander Length
  • 236.
  • 237. Profile: Bed Form
    Water Surface
    Riffle Slope
    Run Slope
    Glide Slope
    Pool Slope
    Thalweg
    Pool Spacing
    Pool Spacing
  • 238.
  • 239. Profile is related to Pattern
  • 240. Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 241. Step Pool Streams
    (high gradient)
    Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.
  • 242. Grade Controls
    Nickpoints