1. Basinwide Visual Estimation Technique BVET
2015

2. What is BVET? Stream habitat inventory method A two-stage technique
Hankin and Reeves (1988)
Dolloff et al. (1993)
A two-stage technique
visual estimates & measurements
Products
calibrated estimate of stream area
inventory of habitat attributes

3. BVET Basics Visual estimates in every habitat unit
Pool
Riffle
Visual estimates in every habitat unit
Measurements at pre-determined intervals

4. BVET Habitat: 5 Steps Complete ‘header information’
Select random number & measurement interval
Walk upstream, stopping to record estimates at upstream end of each habitat unit
At randomly selected unit perform visual estimates, then measurements (paired sample unit)
Proceed upstream estimating in every unit and measuring at pre-determined interval
Repeat steps 4 and 5 until stream end is reached

5. Step 1: Header Information
Stream:
Full stream name per USGS quad map
District:
Forest Service District name
Quad:
Name of USGS 1:24,000 quadrangle on which survey start point is located
Date:
Record start date of survey
Recorder & Observer:
Full names – no ab.
DO NOT change mid-survey
Start GPS:
Map datum = NAD83 CONUS
Coordinate System = UTM
Start location:
Detailed written description of starting point
Notes:
Signs of human activity, water condition, weather, hazards, etc.

6. Header Information on iPad

7. Step 2: Random Number & Interval
Stream < 1.0 km
Measure every 5th unit
Random # 1-5
ex) random number = 3
Paired sample at 3, 8, 13, 18, 23, etc.
Stream > 1.0 km
Measure every 10th unit
Random # 1-10
ex) random number = 3
Paired sample at 3, 13, 23, 33, 43, etc.
Need a minimum of 3 fast water, 3 slow water pairs
More paired samples = smaller confidence intervals

8. Step 3: Estimates for all units
Habitat Type & Number
Distance
Estimated Width
Depth
Substrate
Percent Fines
Large Wood
Hemlock Large Wood

9. 1. Five Habitat Unit Types
Fast water
Turbulent
1. Riffle: <12% gradient
2. Cascade: >12% gradient
flat to convex bottom
Non-Turbulent
3. Run
<12% gradient
flat bottom
Slow water
Turbulent or Non-Turbulent
4. Pool
concave bottom
Non-Turbulent
5. Glide
flat bottom
Special situation
Underground: dry channel

10. Fast Water
Riffle
Run
Cascade

11. Fast Water

12. Slow Water
Pools
Glides

13. Slow Water

14. Unit breaks - clear
Riffle
Pool
Riffle
Pool

15. Unit breaks - fuzzy
Riffle
Glide

16. Unit Number Group slow water: (pools & glides)
Group fast water: (riffles, runs, & cascades)
riffle
run
cascade
pool
glide P1 G2 P3 P4 G5 G6 P7 R1 R5 C4 R2
RN3 R6
Quick quiz:
Random number is 5: Where are 1st fast water and slow water paired samples?

17. 2. Distance Meters from start of survey to upstream end of unit
Measured with a hipchain
P2: 29.3
P1: 10.2
R1: 22.3

18. Hipchain

19. 3. Estimated Width Average Wetted Width Take entire unit into account
P2: 3.0
P1: 2.5
R1: 1.5

20. 4. Depths Maximum Depth Average Depth Deepest point
Average of several points
Change to units

21. Riffle Crest Depth
Measure at upstream end of FAST leading into SLOW; record in FAST data

22. Measuring crest depth
Add rc line

23. 5. Substrate Dominant Subdominant 9 size classes
Covers most surface area in unit
Subdominant
Covers second most surface area in unit
9 size classes

24. Substrate Size Classes
1. Organic dead organics
2. Clay sticky
3. Silt slippery
4. Sand silt- 2mm gritty
5. Small Gravel 3-16mm sand to fingernail
6. Large Gravel 17-64mm fingernail to fist
7. Cobble mm fist to head
8. Boulder >256mm bigger than head
9. Bedrock solid rock

25. How to measure substrate
Substrate size classifications
are based on the b-axis or
the second longest axis A
A= longest axis
C= shortest axis B C
Quick quiz:
Identify the three axis positions

26. 6. Percent Fines
Percent of total area covered by sand, silt, or clay

27. 7. Large Wood (LW) Dead, down, and within bankfull channel
>1.0 m long, >10 cm diameter
Four size classes
1. <5 m long, cm diameter
2. <5 m long, >55 cm diameter
3. >5 m long, cm diameter
4. >5 m long, >55 cm diameter
Rootwad – count separately from attached LW

28. 8. Hemlock Large Wood (LW)
Identifiable as hemlock
Already counted in LW Data; this is a separate count of only Hemlock
Dead, down, and within bankfull channel
>1.0 m long, >10 cm diameter
Combine all 4 size classes

29. LW quick quiz:

30. Congratulations! You know what to estimate in every unit What’s next??
Paired Samples

31. Step 4: Paired samples Every paired pool Every paired riffle
Actual wetted width
Every paired riffle
Hemlock abundance
Hemlock condition
Measured Widths
Bankfull channel width (& Avg. bankfull depth)
Riparian width (left & right)
Gradient
Rosgen
Water temperature
Photo

32. 1. Hemlock Abundance
Estimate the total number of standing hemlocks (live or dead with DBH >10 cm) in the riparian zone (water’s edge to 30 m up the streambank; visually estimated) as you walk between paired sample units
None = no hemlocks
Few = 1-10
Some = 1-50
Many = >50 hemlocks

33. 2. Hemlock Condition
Estimate the condition of standing hemlock trees in the riparian zone as you walk between paired sample units
Healthy/Light Infestation (0-25% needle loss)
Infested (25-75% needle loss)
Dead (>75% needle loss)

34. 3a. Actual (measured) Width
Average wetted width
Measure with a tape measure
Measure in at least three locations

35. 3b&c. Bankfull Channel & Riparian Widths
Bankfull channel width
bankfull to bankfull
Riparian Width
2-times maximum bankfull depth to landform (flood depth)

36. 3b&c. Channel and Riparian Widths
Left Riparian Width
Bankfull Channel Width
Right Riparian Width
2X Max Bankfull Depth

37. Riparian width measurement

38. 4. Gradient Percent slope of the water surface
Measure with a clinometer
Riffles, runs, cascades

39. Be careful measuring gradient

40. 5. Rosgen

41. 6. Water Temperature Place thermometer in flowing water
Out of direct sunlight if possible
Record at measured riffles

42. BVET review Visual estimates in every habitat unit
Measurements at pre-determined intervals

43. Stream Features Waterfalls, Dams, Roads, Trails, etc.
Serve as landmarks
Record distance, GPS, DETAILED description
See features in manual for details

44. 7. Photos Face upstream Use wading rod for scale Get a wide angle
Take at paired fast water units and features/crossings
BAD – can’t see channel
GOOD – can see channel

45. GPS Waypoint Labels S## Start location P## Pause location
S## Start location
P## Pause location
E## End location
T##b Tributary with name shown on quad map
W##b Waterfall
B##b Bridge
Fd##b Ford
D##b Dam
V##b Culvert
O##b Other
## = digits of stream ID
b = use b, c, d, etc to create unique labels
when additional waypoints on the
same stream are needed

46. Ending the Survey Stop when you reach Record At home base
Property boundary
Dry stream for > 500 m
Channel < 1.0 m wide for > 500 m
Record
Time and date
Reason for stopping
GPS coordinates and written description
Be sure header info completed
At home base
Back-up data
Record on master list/map that survey is complete
Download GPS