Module 10/11 Stream Surveys

1
Module 10/11Stream Surveys

• Stream Surveys February 2004Part 5 Watershed
  Assessment

2
Objectives

• Students will be able to
• list characteristics used to describe
  floodplains.
• categorize channel types and patterns of streams.
• calculate the slope of a stream.
• compare bankfull width and wetted width of
  streams.
• list indicators of bankfull discharge.
• categorize stream bank shapes.

3
Stream assessments

• Water quality
• Habitat
• Hydrologic
• Biological
• Watershed

4
Watershed assessments
5
Watershed Assessment

• Land use
• Current and historical pollution sources
• Identify water uses, users, diversions, and
  stream obstructions

6
Floodplain Characteristics

• Land use
• Width
• Active, inactive (incised), inactive (incised),
  anthropogenic (fill)
• Width of riparian buffer zone

7
Stream morphology

• Channel type
• Channel pattern
• Substrate
• Slope
• Sinuosity
• Bankfull discharge
• Riparian characteristics

8
Channel type

• Bedrock
• Colluvial
• Alluvial
• A. Cascade
• B. Step-pool
• C. Plane-bed
• D. Pool riffle
• E. Dune ripple

9
Channel Pattern

• Straight
• Sinuous (image not shown)
• Braided
• Meandering

10
Slope

• Major determinant of river and stream form,
  structure, and performance.
• Determined by measuring the rise of the stream
  water surface over a distance greater than 20
  times the stream's width.

11
Sinuosity

• The ratio of stream length to valley length
• A straight stream has a sinuosity of 1
• Slide to be completed by 3/31/04

12
Bankfull Discharge

• The stream discharge that fills the stream to the
  top of its banks before spilling onto the
  floodplain.

13
Bankfull Discharge

• Indicators (from Harrelson, 1994)
• height of depositional features (bars) indicate
  lowest possible level
• change in vegetation (lower limit of perennial
  species)
• slope changes along bank
• change in particle size along bank
• undercuts on bank
• stain lines

14
Bankfull Discharge
15
Riparian Characteristics

• Width of riparian zone
• Buffer strip
• Type of vegetation
• Trees, bushes, and tall grass
• Lawns
• Bare soil and pavement

16
Canopy cover

• Visual estimate
• Densiometer

17
Stream bank shape
18
Stream surveys - references

• Techniques of Water-Resources Investigations
  Reports
• http//water.usgs.gov/pubs/twri/
• National Field Manual for the Collection of
  Water-Quality Data
• http//water.usgs.gov/owq/FieldManual/
• Rapid bioassessment protocols for wadeable
  streams
• http//www.epa.gov/owow/monitoring/rbp/