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A sampling plan including the location and number of riparian transects
applied should be assigned to based on the above project / area
considerations. An overview field map of the watershed area should be
created to reflect the location and number of riparian transects.
Note: Land owner permission (public or private) should be granted prior
to sampling riparian areas in the field.
4.9.2 Sampling Methods
The intensity of field sampling is a main consideration effecting the
reliability of the photointerpretation. Often increased reliability of land
cover polygon delineation and classification is best achieved through
greater experience and validation through field sampling. Three field
sampling methods for riparian corridors have been identified. Choose
one method which best reflects your project goals and budget.
Method 1: Record riparian land cover classes while traversing upland
cross-sections during SHIM stream survey (also see Cross-section 4.11).
The transect starting point should be located at the end of the floodplain
and continue for at least 50m. Determine the location and extent of each
transect and land cover class using your GPS, compass (set on a specific
bearing) and tight chain. A change in riparian land cover should be
recorded by distance and bearing or GPS co-ordinate. The minimum land
cover class collected should be 5m. The initiation of a new land cover
class, the class type, code, qualifier and structural stage should be
recorded. Field notes and records should enable the project team to
determine the approximate UTM co-ordinate for each change and extent
of land cover class. This is the least intense and least costly sampling
Method 2: Use your assigned land cover class confidence ranking values
to determine the areas needing field sampling. Transect locations should
be selected prior to initiating field sampling. Transect selection should
be based on: (a) 10-20% polygons with high to moderate degree of
confidence, (b) at least 80% polyogns with low degree of confidence. At
least 5% of the entire study should be field sampled. Field photos should
be assigned transects without polygon / land cover class assignments. A
greater number of transects should be planned to allow field crews to
drop inaccessible transects.
Transect location should be determined using UTM co-ordinates from
your map and GPS unit. Use northings and eastings (x and y) co-
rodinates to locate the stream centre line. Local land marks or
knowledge can be used to locate stream centres. From this point,
determine the downstream compass bearing. Perpendicular transects (+
) can be located for left and right banks. This sampling method
provides a moderate field sampling intensity including time and cost.
Method 3: Apply random sampling across all land cover classes to
determine the approximate accuracy of interpreting each class. Point
samples for each polygon should be used to collect this information.
Prior to field sampling, the co-ordinate location of point samples can be
generated from GIS base maps. This information should be transferred
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from the GIS to the field photographs to be used for reference for your
GPS unit in the field. Greater than 5% of the study area is sampled with
this method. This method is the most intensive and requires the greatest
amount of time and budget.
All three field sampling methods should include: (a) observed class for
each area and transect based Table 4.1 (SHIM Land Cover Classes), (b)
Land cover class qualifiers and (c) descriptions of cover structural stage.
The visible dominant and sub-dominant plant species should also be
recorded. Observations made in the field should focus on homogenous
land cover within polygons and avoid transition zones between land cover
Depending on the specific goals of each inventory, additional information
should be collected in the field to describe land cover. This information
ɷ detailed inventory of all vegetation;
ɷ counts of coarse woody debris;
ɷ wildlife species found within the plot;
ɷ diameter at breast height (dbh), height of significant trees;
ɷ description of the site’s soil (e.g. soil pit sampling).
4.10 Field Data Integration And Final Photo-typing
4.10.1 Adding Field Data to the GIS
Following field sampling, collected data should be added to the compiled
GIS project information. If a GPS unit was used to collect field data
points, the x and y co-ordinates and associated notes for each point
should be downloaded and added to the GIS project (each day). Hardcopy
field notes and data should be entered electronically (MS Excel to dbf
format for ESRI ArcView) to incorporate into the GIS project. Field notes
(bearings, distances) should be used to estimate x and y co-ordinates
from the original x/y starting point. Additional field notes should be
added as comments to attribute tables. Tables can be imported into
ArcView GIS using the “Add Event Theme” function. This theme should
now illustrate all the sample data points collected in the field.
4.10.2 Final Photo-typing
Field sample data should be compared with pre-typed photo polygons for
riparian land cover. This review should compare and contrast the field
and map based data by:
ɷ identifying whether land cover or land use classes are under/over
represented in pre-typing polygons;
ɷ building experience in classifying polygons from photos based on
calibration from field observations;
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ɷ understanding the degree of variation in observed characteristics
between and within land cover classes.
During the final photo typing, corrections should be made to the pre-
typed data based (attributes and boundaries for each polygon) on field
sampling experience. When the polygon delineation and attribute coding
is completed, a thorough edit of the database and map against the
original air or ortho-rectified photos is required. Final riparian land cover
should be carefully reviewed to ensure the classes are correct, GIS
polygons are closed areas, structural stages and class qualifiers are
applied (Fig 4.4).
Figure 4.4 Final riparian land cover map and attribute table for the Little
Campbell River. Note land cover polygons extend beyond 100m riparian
4.10.3 Interpretive Mapping
The polygon attribute files for land use and land cover should contain a
complete set of core attributes for each polygon (class names, class
codes, and area), as well as any information collected during field
sampling. GIS projects and software are capable of producing colour
themed maps and summary statistics. Maps can be displayed in many
forms and can include other important SHIM or watershed based themes
including: fish habitat, sensitive areas, impervious surfaces, wildlife
habitat, stormwater runoff, cadastral, and topography.
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4.11 Detailed Stream Channel Cross-sections
A standard SHIM survey involves collection of stream channel wetted, bankfull and
floodplain widths and depths as a general sample of stream conditions along the
channel. When channel complexity increases, more detailed SHIM cross section
survey procedures and tools are needed to sample and describe these channel
areas. More precise measurement of channel shape in conjunction with
descriptions of upland slope and condition can aid in development of hydraulic
models used for regional flood planning. This information is becoming of ever-
greater importance as urban development of headwater areas in British Columbia
continues to increase. Outlined below are the specific field procedures and
measurement points for undertaking detailed channel cross-sections, as well as
description of the accompanying ArcView Cross-Sectional tool designed to
graphically display the collected data.
4.11.1 Cross-sectional Measurement Points
Channel measurements are taken using a folding ruler and a flexible tape
measure stretched perpendicular to the direction of stream flow. A
handheld clinometer and a flexible tape measure are used for
determinations of upland slope. Required cross-sectional measurements
of stream channel widths, depths and elevations as well as upland
riparian features are based on the following survey points defined in
Figure 1 below:
Figure 4.5 Cross section measurement points.
center line - A
left top of bank - J
floodplain edge- F
start of additional riparian bands - I
start of first riparian band - G
bankfull edge -
wetted edge - D
channel measurement - C
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A – channel center line (midpoint of bankfull width)
B – thalweg (deepest channel measurement, may be left or right of
– left channel measurements (CL1 to CL3) – may be taken below or
above water line
– right channel measurements (CR1 to CR3) – may be taken below or
above water line
– left wetted channel edge
– right wetted channel edge
– left bankfull edge
– right bankfull edge
– left floodplain edge
– right floodplain edge
– beginning of first left bank riparian band
– beginning of first right bank riparian band
: measured when a strip of vegetation is too narrow to
include as a distinct riparian band, yet is considered to represent a
significant change in bank slope.
beginning of additional riparian band(s) for left bank
– beginning of additional riparian band(s) for right bank
– top of bank location for left bank
– top of bank location for right bank
Note: Left and right banks are determined facing
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4.11.2 General Field Protocol for Detailed Cross-
1. Stretch out tape measure between two partners and measure/record
2. Go to defined stream center line (midpoint of bankfull width)
3. Measure/record stream center line depth/elevation
4. One partner (who will be the operator of the GPS unit) stays at stream
center line for the duration of the channel measurements and holds
the spool of the tape measure. The second partner (who will actively
take channel measurements) then moves towards the right bank
stretching out the end of the tape measure and using the folding
vertical ruler to take multiple measurements of right channel widths
and depths/elevations and wetted right channel width. After each
channel measurement this partner calls out the associated values to
the GPS operator, who will repeat the numbers (to ensure that the
measurement has been heard correctly in potentially noisy conditions)
and record them in the GPS unit. Upon reaching right bankfull edge,
measure/record right bankfull elevation.
5. Measure/record right floodplain width and elevation.
6. Return to stream center line point and move towards left bank
repeating procedural steps 4 to 6 for all left channel points.
7. Upon completion of channel measurements the GPS operator joins
their partner at the edge of the left floodplain. Begin measurements
of any extra bands (if needed) or left riparian bands from this point.
8. The GPS operator again holds the spool of the tape measure while
their partner stretches out the tape to the end of the extra band or to
the beginning of the next riparian band. This partner calls out the
associated width to the GPS operator who records the measurement.
9. The GPS operator then uses a clinometer to measure the slope of the
left band (in conjunction with their partner providing an adjustment
for ground-to-eye height as described in the following methods
section) and also takes a compass bearing of the transect direction.
Both these measurements are recorded in the GPS data logger.
10. Both partners advance up the left slope taking measurements of
widths and slopes (and associated vegetation information) for each of
the left riparian bands defined. Continue up left bank until all
measured riparian band widths total 50 meters, or (in steeply sloped
areas) extend the riparian measurements to 10m beyond the “top of
bank”, if not included in the 50m measurement.
11. Upon encountering “top of bank”, end the current riparian band at
this point and record a “Yes” in the appropriate data field in the GPS
12. Both partners then walk across the stream channel to the right
floodplain edge and repeat procedural steps 7 to 12 for the right
bank upland measurements from this point.
Note: as an alternative or supplement to tape measurements, “top of bank” and
riparian band breaks may be collected directly as GPS point features.
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Note: a) in the standard SHIM procedures wetted, bankfull and floodplain heights
were measured as depths (+) relative to the stream bottom at channel center line,
whereas; b) in the detailed SHIM cross-sectional procedures channel, wetted,
bankfull and floodplain heights are measured as depths (-) or elevations (+)
relative to the stream water surface level or deepest point in stream channel (if
4.11.3 Measurement Methods
All measurements of cross-sectional channel widths are determined
relative to the stream center line, while measurements of depth (-) and
elevation (+) are determined relative to zero elevation at the level of the
water surface or, if the stream channel is completely dry, at the level of
the deepest point in the stream channel.
Depths: measured by an individual holding a folding ruler vertically
upright from the wetted stream bottom. Markings from the ruler are read
off at the water surface for associated depth measurements taken at
multiple points within the wetted stream channel (CLs and/or CRs).
(Figure 2). All depth measurements (below the water surface) are
recorded as negative values (-).
Elevations: measured by an individual holding a folding ruler vertically
upright from the edge of the water surface (D) while simultaneously
holding one end of a tape measure. For stream channels that are dry the
ruler is held vertically upright from the bottom substrate. A partner
stretches the other end of the tape measure to the appropriate channel
measurement point (i.e., CL, CR, E or F). The first individual then holds
their end of the tape measure horizontal to the folding ruler and reads off
from the ruler the associated elevation measurement for the surveyed
point (Figure 2). Elevation measurements are recorded as positive values
(+). For sections of the stream channel that are dry, channel
measurements (including CLs, CRs or center line) are measured as
elevations (+) relative to the surface level of the existing water flow. If the
entire stream channel is dry (no flowing water), then measurements for
all channel features are recorded as elevations (+) relative to the deepest
point of the channel (B).
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Figure 4.6 Depth and elevation measurements used in the detailed channel
Widths: determined by anchoring one end of a flexible tape measure
(either by one partner holding a tape end or else securing it with a rock
or stick) while stretching the other end across to a desired survey point.
The measured distance is then read off from the markings indicated on
Slope: determined in degrees with a clinometer, a sighting device used to
measure the angle of a line of sight above or below horizontal. To use a
clinometer, you look through the eyepiece with one eye to see the angle
measuring scale and a horizontal line. With the other eye, you sight on
the point of land you want to measure. When the horizontal line is
aligned with your survey point, you simply read the scale to find the
gradient (Figure 3).
Figure 4.7 Slope measurements with a handheld clinometer.
Gradient is a measure of how quickly the land falls (or rises) over a
measured horizontal distance. The higher the gradient, the steeper the
slope. Steep, high gradient slopes lose height quickly over short
distances, whereas gentle, low gradient slopes lose very little height over
comparable distances. To use the clinometer in the field, first determine
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the height from the ground to the eyes of the person holding the
instrument. This height can be flagged on a pole or stick as an
adjustable siting marker, which will be held vertical from the base of the
survey point by a second team member. All clinometer readings should
then be taken in line with this marker to adjust for individual variations in
observer height (Figure 4). Before commencing measurements of the
slope, determine the aspect (direction that the slope is facing) with a
magnetic compass (correctly adjusted for declination).
Figure 4.8 Adjusting for ground to eye height when taking clinometer
4.11.4 Channel Measurements
Center line: no width is taken here (only depth or elevation), as the
channel center line (A) provides the zero reference point for all cross-
sectional width measurements. Accurate spatial co-ordinates for this
point are captured with a Trimble Pathfinder GPS unit.
Left channel widths (CL1, CL2 and CL3): measured for each by
stretching a tape measure from the stream center line (A) and
determining incremental widths across the channel (Figure 5). One to
three channel widths may be taken in conjunction with depths or
elevations to provide a good representation of the channel bottom. A
separate left channel width (D
) is taken at the wetted edge of the stream.
Right channel widths (CR1, CR2 and CR3): measured by stretching a
tape measure from the channel center line (A) and determining
incremental widths across the channel (Figure 5). One to three channel
widths may be taken in conjunction with depths or elevations to provide a
good representation of the channel bottom. A separate right channel
) is taken at the wetted edge of the stream.
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