Transcript Reference Condition

EXPECTED CONDITION
Introduction to Some Basic Concepts
for the Development of
Colorado’s Conceptual Model
PROJECT OBJECTIVES
 Develop a ‘top down’ reference stream/reach
screening approach
 Develop a process to identify ‘least disturbed’
reference sites in any bio-physical stratum
 Key: practical, based on readily available data,
reproducible, regionally flexible
 Develop a Protocol or Guidance document that
will reflect Colorado’s approach to Biological
Assessments
“The true health of our aquatic
environments is reflected by the
biological communities that reside
within them”
Prof. J. Karr
University of Washington
WHAT ARE REFERENCE CONDITIONS?
(from EPA)
• Reference conditions represent the best
biological conditions that can be found in a
body of water that has not been impacted by
humans.
REFERENCE CONDITION
CAN BE:
• Minimally Disturbed Condition
• Least Disturbed Condition
• Best Attainable Condition
MINIMALLY DISTURBED CONDITION
• Condition in the absence of significant, or minimal
human disturbance (e.g., “natural”, “pristine”, or
“undisturbed”)
• An absolute. Some regions might have no sites
that meet minimal disturbance criteria.
• MDC changes little over time, due to natural
processes
• Stable benchmark
• Derived from minimally disturbed reference sites
LEAST DISTURBED CONDITION
• Best available given today’s state of the landscape
• Found in conjunction with the best available
physical, chemical, and biological habitat given
today’s state of the landscape
• Relative. No matter how disturbed the region,
some sites are likely less disturbed than others.
• Can change over time as land use and
management practices change
• Derived by characterizing least disturbed
reference sites
BEST ATTAINABLE CONDITION
• Best Attainable Condition - this condition
is equivalent to the ecological condition of
(hypothetical) least disturbed sites where
the best possible management practices are
in use
COLORADO’S PROPOSED DEFINITION
 Expected Condition – the physical, chemical and
biological conditions found at reference sites should
represent the best attainable conditions that can be
achieved by similar streams within a particular
geographic region, given today’s state of the
landscape
THERE ARE TWO APPROACHES TO
ESTIMATE THE REFERENCE (EXPECTED)
CONDITION:
– Classification predicts the expected biotic
condition of a waterbody from previously
observed associations between biotic attributes
and categorical descriptors of a waterbody’s
environmental setting.
– Modeling predicts the expected biotic condition by
mathematically describing how biota vary along
environmental gradients.
IMPROPER CLASSIFICATION LEADS TO
BAD DECISIONS:
Scientist,
Manager, or
Regulator
Stakeholder
THE EXPECTED CONDITION OF A SITE
WILL ALWAYS BE SOMEWHAT “FUZZY”
BECAUSE:
o
Un-impaired sites are not static - they are in
dynamic equilibria.
o
There is measurement error associated with
estimating the value of an indicator.
o
There is variance associated with the effects of unmeasured, naturally occurring factors.
Reference Site Selection
THE WORLD IS NATURALLY
HETEROGENEOUS AND “EXPECTED”
MAY NOT BE OBVIOUS
We need to establish the correct match
between an assessed site and its
expected condition, so we need …
GOOD REFERENCE SITES THAT
• Mimic natural gradients of the region of interest,
and ….
• are representative of the stream and habitat of
interest
REFERENCE SITE SELECTION IS:
• An iterative screening process for selecting sites
• That are minimally or least disturbed by
human activities and resultant stressors
• That are representative of the aquatic
resource in the region of interest
THE PROBLEM OF REPRESENTATIVENESS
o
This problem really boils down to whether the
range of environmental and biological
conditions in the population of reference sites
is equivalent to the range that would occur in
the population of all other sites of interest.
o
Reference site ‘quality’ will almost always
vary across classes of sites, so we must be
careful about what we mean by “reference”.
ACCOUNTING FOR NATURAL
VARIABILITY – HOW MUCH IS ENOUGH?
o
How much we need to account for is a
function of how small of a response we
want/need to detect, which needs to be
decided by stakeholders up front!!!
THE ROLE OF REFERENCE SITES IN
CLASSIFICATION AND MODELING:
o
o
The use of reference sites is an empirical approach
to estimating Reference Condition.
Accurate and precise predictions from reference
site data depend on:
– Agreed upon and acceptable criteria for defining
reference site quality,
– Acceptable means of extrapolating/interpolating.
A SIMPLE CONCEPTUAL MODEL:
The key is to identify common patterns of
biological responses to human disturbances
Human Activities
(Disturbance)
Stressors
(Habitat Responses)
Biological Responses
A more complex conceptual model
(from Bryce et al. 1999. J. Am. Wat. Resour. Assoc. 35:23-36)
Human
Activity
Urbanization
Ag/CAFO/
Silviculture
Channelization
Levees
Roads/Culverts
Erosion
MWTPs/CSOs
Septic systems
Imperviousness
Fragmentation
Stressors
(Habitat
change)
Biological
Responses
Grazing
Harvest
Dams
Channelization
Diversions
Levees
Roads/Culverts
Erosion
Fertilizer
Pesticides
Compaction
Fragmentation
Mining/
Drilling
Extraction
Metals
Liming
Tailings
Valley Fill
Diversions
Roads/Culverts
Erosion
Petroleum
Pipelines
Fragmentation
Compaction
Industry/
Power Gen.
Dams
Stacks
Liming
Wastewater
WTP/CSOs
Roads/Culverts
Channelization
Revetments
Imperviousness
Fragmentation
Habitat Flow Sediment Nutrient Oxygen Temperature Toxics
Altered Biological Structure/Function
EXTENSIVE DATA
• Identify sources of complete coverages
– GIS resources?
– Geo-Referenced databases?
• Sources of data
– At the landscape screening level
• Land use/cover (TM imagery; other satellite
imagery)
• Roads
• Population density/points sources
• Mines
• Feedlots
•…
OFFICE DATA
• Identify sources of candidate sites
– Air photos, digital orthophoto quads, maps
• Sources of data
– Terraserver
– USGS topo maps/local maps
– National High Altitude Photography (NHAP)
– Satellite imagery
SITE RECONNAISSANCE
•
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By air
By ground site visit
ID disturbances missed by the coarser filters
Local knowledge/local land managers
Input from Best Professional Judgement
SITE MEASUREMENTS
• Apply routine field protocol
– EMAP
– USGS
– STATE
– RIVPACS
• To identify disturbances missed by coarser
screens:
– Riparian habitat
– Physical habitat
– Water quality
– Biota
SOME EXAMPLES OF CRITERIA TO
SELECT REFERENCE SITES
CRITERIA SET # 1
• Drainage: entirely within subregion
• Land use: >80% forest; no ag/urban; no recent
disturbance, e.g., construction; clearcutting
• Habitat: No cattle in w/s; no disturbances
• Channel: Characteristic of region
• Riparian veg: > 30m buffer for most of w/s
• Instream substrate: no significant siltation or
embeddedness
• Water Quality: No point sources; no recent spills;
pH>6.
CRITERIA SET # 2
“Filters”: exclude all sites with:
• sulfate over 400 ueq/L (mine drainage)
• acid neutralizing capacity less than 50 ueq/L (acid rain)
• average RBP habitat score less than 16 (habitat)
• total phosphorus over 100 ug/L (nutrient enrichment)
• total nitrogen over 750 ug/L (nutrient enrichment)
• chloride over 100 ueq/L (general watershed disturbance
• total benthic count less than 100 individuals (inadequate
sample)
Criteria for Alaska Reference Sites
(Must meet all criteria)
 no channelization
 no upstream impoundments
 no known point source dischargers
 dissolved oxygen greater or equal to 5 ppm
 urban land use less than 15% in catchment
 mining and/or logging affecting less than 15% in
catchment
 forest land use (or other natural wetland, grassland)
greater than 70% in catchment
 riparian buffer width greater or equal to 18 m
EXAMPLE OF CRITERIA FROM
MISSOURI
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Wastewater treatment plants and other point sources
Confined animal feeding operations
Instream habitat
Riparian habitat
Land use and land cover, broad scale
Land use and land cover, site specific
Physical and chemical water parameters
Biological metrics
Faunal assemblages
Altered hydrologic regime
Representativeness
Bioassessment and Biocriteria Program Development Timeline
INITIAL DEVEOPMENT PHASE
0-18 MONTHS
INITIAL IMPLEMENTATION PHASE
12-24 MONTHS
INITIAL ASSESSMENT PHASE
18 MO – 6 YEARS
FULL ASSESSMENT PHASE
5 – 10 YEARS
Start-Up Tasks: Logistics
Acquire Staffing:
 Professional biologists with
expertise & training
 Database manager
 Interns/technicians (field work,
lab tasks
Acquire Facilities & Equipment:
 Outfit laboratory and field facility
 Office accommodations
 Database support infrastructure
Methods Development:
 Review and select candidate
methods and protocols
 Consider MQO/DQO needs
 Test methods for applicability
 Analyze test results – select
methods
Start-Up Tasks:
Implementation
Program Implementation
Initiate Field Sampling:
 Review spatial designs
 Develop QA/QC and QAPP
 Develop sampling plans in
accordance with monitoring
strategy
 Pilot assessments
Classification Issues:
 Consider spatial stratification
issues
 Develop and test reference
condition approach
 Select and sample reference
sites
 Develop index development
and calibration strategy
Biocriteria Development:
 Select candidate metrics and/or
assessment tools
 Develop refined uses narratives
 Test metrics and develop
calibrated indices
 Evaluate via bioassessments
Water quality Program Support:
 Develop capacity to support
WQ programs (WQS/UAAs,
TMDLs, permits, planning)
 Formalize water quality
program support as capacity is
developed
Program Maintenance
Biocriteria Development:
 Refine metrics and develop
calibrated indices
 Develop reference benchmarks
for calibrated indices according
to classification scheme and by
major aquatic ecotype
Water quality Program Support:
 Fully functioning bioassessment
program supports WQS (UAAs,
aquatic life use support) and
basic program needs
(305b/303d)
 Program development should
be fully initiated – e.g.,
integrated chemical, physical,
and biological database
supports criteria & policy
development
Continuously evaluate program
Quality Improvement Process
Evaluate effectiveness of initial decisions – make needed adjustments