Geology 230 Groundwater/ surface water interaction Tim Horner Geology Department, CSU Sacramento

1. SACRAMENTO STATE Geology 230Groundwater/ surface water interactionTim HornerGeology Department, CSU Sacramento Week 1: Stream classification Reading assignment: 1) EPA Watershed Academy, 2005, Fundamentals of the Rosgen Stream Classification System:  Accessed 8/29/05 at http://www.epa.gov/watertrain/stream_clas/index.htm. 2) Montgomery, D. R., and Buffington, J. M., 1994, Channel-reach morphology in mountain drainage basins: Geological Society of America Bulletin, v. 109, pp. 596-611. 3) Mial, A. D., 1977, Lithofacies Types and Vertical Profile Models in Braided River Deposits: A Summary, in, Fluvial Sedimentology — Memoir 5, Fluvial Facies Models, pp. 597-604.

2. Methods used to characterize streams: Miall- A sedimentologist’s approach Rosgen- Based on channel morphology Montgomery and Buffington- More process based

3. Miall’s lithofacies designations From Miall, 1977

4. Miall’s stream types- braided rivers From Miall, 1977

5. Miall’s stream types- braided rivers Examples are intended to show all of the variability in braided streams. Several are based on glacial outwash High energy with limited sediment supply Debris flow proximal -------------------------distal From Miall, 1977

6. Rosgen’s classification system From: EPA Watershed Academy, 2005 Advantages Disadvantages • Simple key, can be used by inexperienced field hands • Looks mostly at form • Simple key, can be used by inexperienced field hands • May not represent scale accurately

7. Rosgen’s classification system • Three main parts: • Level I classification, which is based on the stream characteristics that result from relief, landform, and valley morphology; • Valley type, a primary determinant of stream form; • Level II classification, which provides more detailed morphological description of stream type from field measurements of channel form and bed composition. From: EPA Watershed Academy, 2005

8. Level I Stream Classification • The Level I stream classification serves four primary functions: • Provide for the initial integration of basin characteristics, valley types, and landforms with stream system morphology. • Provide a consistent initial framework for organizing river information and communicating the aspects of river morphology. Mapping of physiographic attributes at Level I can quickly determine location and approximate percentage of river types within a watershed and/or valley type. • Assist in the setting of priorities for conducting more detailed assessments and/or companion inventories. • Correlate similar general level inventories such as fisheries habitat, river boating categories, and riparian habitat with companion river inventories. • The Level 1 Stream Classification produces a letter: A - G

9. Level I Stream Classification • Is landscape scale • Can be accomplished with topo maps or air photos From: EPA Watershed Academy, 2005

10. Level 1 assessment Depends on basin-scale factors: From: EPA Watershed Academy, 2005

11. From: EPA Watershed Academy, 2005 High energy, high sediment load multiple channels anastomosing stable channel, more entrenched, low relief • Variables: • gradient • width/depth ratio • lateral confinement • sinuosity • entrenchment • meander geometry • erosion • sinuosity

12. Level 2 assessment: Valley type There are 11 Valley Types. Valley types may correlate with Level 1 stream types From: EPA Watershed Academy, 2005

13. Level 2 assessment: Valley type There are 11 Valley Types. Valley types may correlate with Level 1 stream types Type X, XI may include wetlands From: EPA Watershed Academy, 2005

14. Part 3: Level II Stream Classification From: EPA Watershed Academy, 2005 Cross-sectional measurements Entrenchment Ratio: A computed index value which is used to describe the degree of vertical containment of a river channel (width of the flood prone area at an elevation twice the maximum bankfull depth/bankfull width). Width/depth Ratio: An index value which indicates the shape of the channel cross-section (ratio of bankfull width/mean bankfull depth). Dominant Channel Materials: A selected particle size index value, the D50, representing the most prevalent of one of six channel material types or size categories, as determined from a channel material size distribution analysis. Longitudinal Profile measurements Slope: Slope of the water surface averaged for 20-30 channel widths. Bed Features: Secondary delineative criteria describing channel configuration in terms of riffle/pools, rapids, step/pools, cascades and convergence/divergence features which are inferred from channel plan form and gradient. Plan-form (pattern) measurements Sinuosity: Defined as stream length/valley length or valley slope/channel slope). Meander Width Ratio: A secondary delineative criteria defined as meander belt width/bankfull width that describes the degree of lateral channel containment, and is primarily used in assisting aerial photo delineation of stream types.

15. Part 3: Level II Stream Classification From: EPA Watershed Academy, 2005

16. Part 3: Level II Stream Classification From: EPA Watershed Academy, 2005

17. Gathering field data for Level II Stream Classification: Visual or physical indicators of the bankfull stage: The presence of a floodplain at the elevation of incipient flooding. The elevation associated with the top of the highest depositional features (e.g., point bars, central bars within the active channel). These depositional features are especially good stage indicators for channels in the presence of terraces or adjacent colluvial slopes. A break in slope of the banks and/or a change in the particle size distribution, (since finer material is associated with deposition by overflow, rather than deposition of coarser material within the active channel). Evidence of an inundation feature such as small benches. Staining of rocks. Exposed root hairs below an intact soil layer indicating exposure to erosive flow. Lichens and - for some stream types and locales - certain riparian vegetation species From: EPA Watershed Academy, 2005

18. Measuring bankfull stage in the field: From: EPA Watershed Academy, 2005

19. Estimating entrenchment ratio: From: EPA Watershed Academy, 2005

20. Estimating width/depth ratio: From: EPA Watershed Academy, 2005

21. Estimating sinuosity: From: EPA Watershed Academy, 2005

22. Estimating slope: From: EPA Watershed Academy, 2005

23. Estimating channel material (pebble counts): From: EPA Watershed Academy, 2005

24. Summary: Rosgen’s stream classification method From: EPA Watershed Academy, 2005

25. Montgomery and Buffington, 1997: • Looks at reach-level stream features • 7 alluvial channel types: • colluvial • bedrock • cascade • step pool • plane bed • pool riffle • dune riffle Montgomery and Buffington, 1997

26. Montgomery and Buffington channel types: From: Montgomery and Buffington, 1997

27. Montgomery and Buffington channel types: From: Montgomery and Buffington, 1997

28. Montgomery and Buffington channel types: From: Montgomery and Buffington, 1997

29. Montgomery and Buffington: channel type vs. gradient From: Montgomery and Buffington, 1997

30. Montgomery and Buffington: channel type vs. drainage area From: Montgomery and Buffington, 1997

31. Montgomery and Buffington: channel type vs. roughness and grain size From: Montgomery and Buffington, 1997

32. Montgomery and Buffington: channel type vs. roughness and grain size From: Montgomery and Buffington, 1997

33. Montgomery and Buffington: channel type transport capacity From: Montgomery and Buffington, 1997

34. Montgomery and Buffington: channel response to changes in sediment supply and discharge From: Montgomery and Buffington, 1997

35. Other methods of stream characterization: Strahler, order of streams