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RTI International is a trade name of Research Triangle Institute.www.rti.org
Biological Fidelity Analysis
of EFS Stream Classes
Funded by: Environmental Defense Fund
Conducted by: RTI International
RTI International
Project Objectives:
To adopt a stream classification system that
represents the distribution of aquatic biota in North
Carolina
–evaluate the 7 stream classes of the Environmental Flow
Specialist (EFS) hydrological stream classification system:
A. Coastal Streams
B. Small Stable Streams
F. Medium Stable Streams
C. Large Stable Streams
E. Large Piedmont Rivers
D. Small Flashy Streams
G. Small Seasonal
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Project Objectives:
To adopt a stream classification system that
represents the distribution of aquatic biota in North
Carolina
–Compare fidelities of aquatic biota to different stream
classification systems
–If necessary, modify the EFS stream classes to more
accurately describe the distribution of biota
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Stream Class – Biological Fidelity Analysis
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Step 1.
Objective: Examine the biological fidelity of aquatic
biota to the 7 EFS stream classes
Pair USGS gages (185 gages) to biota at biological
monitoring sites to determine stream class –
biology assignments
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Step 1.
Aquatic Biota
Database
Supporting NC Agency, Department or
Program
Benthic
macroinvertebrate
N.C. Department of Environment and Natural
Resources (NCDENR) Division of Water Quality
(DWQ)
Stream fish
community
NCDENR DWQ
Natural Heritage
Inventory
NCDENR Natural Heritage Program
Trout database N.C. Wildlife Resources Commission
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Step 1.
Objective: Examine the biological fidelity of aquatic
biota to the 7 EFS stream classes
Pair USGS gages (185 gages) to biota at biological
monitoring sites to determine stream class – biology
assignments
Generate 500 “virtual gages” with WaterFALLTM
hydrologic data to assign stream classes to
biological monitoring stations without gages
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Criteria for biological monitoring stations
Monitoring stations distributed evenly across the
state
Eliminate:
–catchments with impaired water quality (as determined by
NC Division of Water Quality – 303d listings)
–catchments with major in-stream flow alterations
(impoundments, discharges and/or intake points)
–catchments with “poor” or “questionable” biological
monitoring data
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Criteria for biological monitoring stations
Select:
–catchments that contain biological monitoring stations from
multiple aquatic biota datasets
–biological monitoring stations sampled during years with
average climate conditions
–biological monitoring stations with most recent biological
data
–biological monitoring stations with multiple biological
measurement dates and presence/absence that doesn’t
change by > 10%
–biological monitoring stations upstream from USGS
reference gages
RTI International
Step 1.
Objective: Examine the biological fidelity of aquatic
biota to the 7 EFS stream classes
Pair USGS gages (185 gages) to biota at biological
monitoring sites to determine stream class – biology
assignments
Generate 500 “virtual gages” with WaterFALLTM
hydrologic data to assign stream classes to biological
monitoring stations without gages
Random Forest non-parametric analyses to
determine probability of species occurrence and
biological fidelity to stream classes
RTI International
Random Forest is a decision-tree modeling and classification
approach (Cutler et al., 2007)
A decision tree is a predictive model that uses a set of binary
rules (yes/no) to split the data based on the predictor variable
Random Forest Approach
All Stream Class
and Aquatic
Biology Data
Stream Class A
Species 1
present
Species 2
present
Species 3
present
Species 4
present
YesYes No No
Stream Class B
Predictive
Variable
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Random Forest Analysis -Biological fidelity
to stream class
= high probability
= medium probability
= low probability
= absent
Aquatic
species
Stream Class
ABCDEFG
1
2
3
4
5
6
7
8
9
10
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= high probability
= medium probability
= low probability
= absent
Random Forest Analysis –NO Biological
fidelity to stream class
Aquatic
species
Stream Class
ABCDEFG
1
2
3
4
5
6
7
8
9
10
RTI International
Step 1.
Objective: Examine the biological fidelity of aquatic
biota to the 7 EFS stream classes
Pair USGS gages (185 gages) to biota at biological
monitoring sites to determine stream class – biology
assignments
Generate 500 “virtual gages” with WaterFALLTM
hydrologic data and EFS software to assign stream
classes to biological monitoring stations without gages
Random Forest non-parametric analyses to determine
probability of species occurrence and biological fidelity
to stream classes
RTI International
Stream Class – Biological Fidelity Analysis
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Step 1a.
Objective: To test biological fidelity to other stream
classification systems and compare with EFS
–Other stream classifications:
McManamay et al. (2011) – regional classification of
unregulated streams
Konrad (in review) –hydrological classification in
southeastern U.S.
–Analyses:
comparison of classes determined by the three classification
systems
comparison of biological fidelities to the three stream
classification systems
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Stream Class – Biological Fidelity Analysis
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Step 2.
Objective: Assess the biological fidelity of aquatic
biota to stream classes that only include streams that
are not altered (i.e., minimal instream flow
alterations).
re-classify streams (at 185 gage locations) using
WaterFALLTM hydrologic data (unaltered condition) and
EFS software
streams that change classes with the reclassification are
considered “altered”
eliminate “altered” streams from dataset
repeat Random Forest non-parametric analyses to
determine if biological fidelity to stream classes is
improved with dataset restricted to non-altered streams
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Stream Class – Biological Fidelity Analysis
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Step 3.
Objective: Evaluate the ability to improve biological
fidelity to stream classes by sub-dividing and/or
aggregating the 7 EFS stream classes
•Repeat Random Forest non-parametric statistical
analyses to determine aquatic biota associations to
stream classes divided by:
Physiographic/Eco region
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Physiographic/Eco Region Classifications
Classification System Reference
Ecoregions of the
Conterminous United
States
Omernik (1987)
Bailey’s Ecoregions and
Subregions of the United
States
http://www.nationalatlas.gov/mld/ecoregp.html,
http://na.fs.fed.us/sustainability/ecomap/sectio
n_descriptions.pdf
Physiographic Regions
of the Conterminous
United States
Fenneman and Johnson (1964)
TNC Ecological
Drainage Units
http://www.2c1forest.org/atlas/metadata/edu_
metadata.htm
Hydrologic Landscapes Wolock (2003)
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Omernik Ecoregions – Level III
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Bailey Ecoregions
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Fenneman Physiographic Regions
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TNC Environmental Drainage Units
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Wolock’s Hydrologic Landscape Regions
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Step 3.
Objective: Evaluate the ability to improve biological
fidelity to stream classes by sub-dividing and/or
aggregating the current NC hydrological stream
classifications
Repeat Random Forest non-parametric statistical
analyses to determine aquatic biota associations to
stream classes divided by:
Physiographic/Eco region
Flow metrics that determine stream class
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Step 3.
Objective: Evaluate the ability to improve biological
fidelity to stream classes by sub-dividing and/or
aggregating the current NC hydrological stream
classifications
“Clusters” of biota may indicate the ability to divide
stream classes
Biota occurring in multiple stream classes may offer
opportunity to combine classes
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Questions?