BEC_Proposal

RTI International
RTI International is a trade name of Research Triangle Institute.www.rti.org
Proposed approach to develop a
Biological-Environmental Classification
(BEC) system and supporting flow –
biology relationships in North Carolina
Funded by: Environmental Defense Fund
Conducted by: RTI International
RTI International
Background:
Biofidelity Analysis showed:
–EFS and McManamay stream classifications systems could
not be extrapolated beyond catchments with USGS gages
49-64% match between classifications based on USGS gage
versus WaterFALL modeled hydrologic data
~ 270 USGS gages in NC
~70,000 NHD+ catchments
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Background:
CONCLUSION:
Need a classification system that is:
–Not based on sensitive threshold values
–Consistent and reproducible using USGS stream gage and
modeled data
–Easy to understand and implement
–Can be applied throughout state
–Captures the distribution of aquatic biota in North Carolina
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Objectives of Proposed Project:
1.Develop a classification system based on geographical
assemblages of aquatic biota (fish) and associated
environmental (physiographic and hydrologic) attributes
– Biological-Environmental Classification (BEC) system
2.Determine flow–biology response relationships for each
BEC class
3.Link significant flow metrics (and associated flow–
biology relationships) to each BEC class to support
ecological flow determinations
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Step 1 – Determine
BEC classes based on
aquatic biota
assemblages and
environmental
characteristics
Step 2 – Determine
flow-biology
relationships for each
BEC class
Step 3 –Link
significant flow metrics
to each BEC class to
support determination
of ecological flows
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Step 1 – Determination of BEC class
-Iterative, cluster-classification approach using
aquatic biota and environmental attribute data to
develop BEC classes:
-Aquatic biota:
-NC fish (DWQ Fish community dataset) – 858 monitoring
stations
-Environmental attributes:
-Regional classifications (6 classifications – ecological,
physiographic, hydrologic)
-Physiographic (watershed and stream channel)
characteristics
-Climatic variables
-Hydrologic variables
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Environmental attributes potentially used in
BEC classes
Environmental Attributes Variable
Average precipitation
Average temperature
Elevation
Channel Width
Channel Gradient
Channel Sinuosity
Local connectivity (stream
fragmentation)
Stream size/Drainage area
Geology (catchment and local)
Hydrologic Stream hydrologic regime (ground-
water vs. surface water dominated)
Climatic
Physiographic
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Step 1 – Determination of BEC class
-Iterative, cluster-classification approach using
aquatic biota and environmental attribute data to
develop BEC classes
RTI International
Abundance
Species
Si
t
e
s
Variables
Environment
Si
t
e
s
Cluster
Analysis
3 4 5 X7X
Analysis of
Similarity
Biology
7
Classification
Decision Tree
Environment
Environmental
Attribute Based
Classes
Environmental
Attribute Based
Classes
APPROACH 1 APPROACH 2
Environment
5
Environment
Biology
Based
Classes
Biology
Based
Classes
53
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NCDENR
– EF SAB
feedback
Biology
Based
Classes
Biology
Based
Classes
Environmental
Attribute
Based Classes
Environmental
Attribute
Based Classes
APPROACH 1 APPROACH 2
Final BEC
Classes
Final BEC
Classes
RTI International
Step 1 – Determine
BEC classes based on
aquatic biota
assemblages and
environmental
characteristics
Step 2 – Determine
flow-biology
relationships for each
BEC class
Step 3 –Link
significant flow metrics
to each BEC class to
support determination
of ecological flows
RTI International
Step 2. Determination of Flow-Biology
Relationships
Flow alteration – biological response relationships
for each BEC class:
–Flow alteration (% change):
Ecologically-relevant flow metrics
based on TNC Indicators of Hydrologic Alteration (IHA)
NC DENR management-focused
Generated using WaterFALL model
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Expressed as % change:
-Historic = 1970’s land-cover or Potential Natural Vegetation
(PNV), no in-stream flow alterations
-Current = 2006 land-cover, with discharges, withdrawals, and
impoundments
Flow Metrics
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Step 2. Determination of Flow-Biology
Relationships
Flow alteration – biological response relationships
for each class:
–Biological response:
NC Fish Community data (858 catchments with monitoring
stations)
Level Analysis metric
- Individual species - Species abundance (count of individuals)
- Full community - Number of species (diversity)
- Habitat guilds (6) - Shannon Weaver Diversity Index
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Step 2. Determination of Flow-Biology
Relationships
Flow alteration – biological response relationships
for each class:
–Analysis:
Space-for-time analysis
Quantile regression (90th percentile)
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90% of zero flow alteration“gold standard”
No observed
values
No
observed
values
90th %
Regression
(p<0.001)
90th %
Regression (p
= 0.08)
Example of Flow-Biology Relationship
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Step 1 – Determine
BEC classes based on
aquatic biota
assemblages and
environmental
characteristics
Step 2 – Determine
flow-biology
relationships for each
BEC class
Step 3 –Link
significant flow metrics
to each BEC class to
support determination
of ecological flows
RTI International
Link statistically significant flow metrics (from the
flow-biology analyses) to each BEC class
Some metrics (associated with individual species
analyses) may be associated with more than one
BEC class
Step 3. Link flow metrics to each BEC class
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Questions?