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EXPECTED CONDITION

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Develop a top down' reference stream/reach screening approach ... Some regions might have no sites that meet minimal disturbance criteria. ... – PowerPoint PPT presentation

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Title: EXPECTED CONDITION


1
EXPECTED CONDITION
  • Introduction to Some Basic Concepts
  • for the Development of
  • Colorados Conceptual Model

2
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 Colorados approach to Biological
    Assessments

3
The true health of our aquatic environments is
reflected by the biological communities that
reside within them Prof. J. Karr
University of Washington
4
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.

5
REFERENCE CONDITIONCAN BE
  • Minimally Disturbed Condition
  • Least Disturbed Condition
  • Best Attainable Condition

6
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

7
LEAST DISTURBED CONDITION
  • Best available given todays state of the
    landscape
  • Found in conjunction with the best available
    physical, chemical, and biological habitat given
    todays 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

8
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

9
COLORADOS 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 todays state of the landscape

10
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 waterbodys
    environmental setting.
  • Modeling predicts the expected biotic condition
    by mathematically describing how biota vary along
    environmental gradients.

11
IMPROPER CLASSIFICATION LEADS TO BAD DECISIONS
Scientist, Manager, or Regulator
Stakeholder
12
THE EXPECTED CONDITION OF A SITE WILL ALWAYS BE
SOMEWHAT FUZZY BECAUSE
  • Un-impaired sites are not static - they are in
    dynamic equilibria.
  • There is measurement error associated with
    estimating the value of an indicator.
  • There is variance associated with the effects of
    un-measured, naturally occurring factors.

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15
Reference Site Selection
16
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

17
GOOD REFERENCE SITES THAT
  • Mimic natural gradients of the region of
    interest, and .
  • are representative of the stream and habitat of
    interest

18
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

19
THE PROBLEM OF REPRESENTATIVENESS
  • 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.
  • Reference site quality will almost always vary
    across classes of sites, so we must be careful
    about what we mean by reference.

20
ACCOUNTING FOR NATURAL VARIABILITY HOW MUCH IS
ENOUGH?
  • 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!!!

21
THE ROLE OF REFERENCE SITES IN CLASSIFICATION AND
MODELING
  • 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.

22
A SIMPLE CONCEPTUAL MODELThe key is to identify
common patterns of biological responses to human
disturbances
23
A more complex conceptual model
(from Bryce et al. 1999. J. Am. Wat. Resour.
Assoc. 3523-36)
Urbanization Channelization Levees
Roads/Culverts Erosion MWTPs/CSOs
Septic systems Imperviousness
Fragmentation
Ag/CAFO/ Silviculture 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
Human Activity
Stressors (Habitat change)
Habitat Flow Sediment Nutrient Oxygen
Temperature Toxics
Biological Responses
Altered Biological Structure/Function
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25
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

26
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

27
SITE RECONNAISSANCE
  • By air
  • By ground site visit
  • ID disturbances missed by the coarser filters
  • Local knowledge/local land managers
  • Input from Best Professional Judgement

28
SITE MEASUREMENTS
  • Apply routine field protocol
  • EMAP
  • USGS
  • STATE
  • RIVPACS
  • To identify disturbances missed by coarser
    screens
  • Riparian habitat
  • Physical habitat
  • Water quality
  • Biota

29
SOME EXAMPLES OF CRITERIA TO SELECT REFERENCE
SITES
30
CRITERIA SET 1
  • Drainage entirely within subregion
  • Land use gt80 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 gt 30m buffer for most of w/s
  • Instream substrate no significant siltation or
    embeddedness
  • Water Quality No point sources no recent
    spills pHgt6.

31
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)

32
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

33
EXAMPLE OF CRITERIA FROM MISSOURI
  • 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

34
Bioassessment and Biocriteria Program Development
Timeline
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