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Rivers Intercalibration Phase 2 Key Cross-GIG activities 2008-2011

This project aims to stabilize concepts, harmonize criteria, quantify thresholds, and produce a common procedure for intercalibration, with a focus on large rivers. The relationship between driving forces and biological response in different human and natural contexts will be examined, as well as the use of expert judgement and underlying concepts for reference thresholds.

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Rivers Intercalibration Phase 2 Key Cross-GIG activities 2008-2011

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  1. Rivers Intercalibration Phase 2Key Cross-GIG activities 2008-2011 Refining Reference Conditions Intercalibrating Large River Ecological Status Initial scoping meeting Lyon May 2008 Roger Owen Jean-Gabriel Wasson John Murray-Bligh

  2. Reference conditionsWe need to: Intercalibration Phase 2 2008-2011: Rivers • Stabilise the concepts • Harmonise the criteria (QE, GIGs) • Quantify the thresholds : search for "no effect" thresholds • Produce a common procedure

  3. Reference conditions : the present situation Intercalibration Phase 2 2008-2011: Rivers • Mix of quantitative criteria and "qualitative" evaluation • Mix of: • Driving forces (land cover), • Pressures (dams, effluents) • Stressors (chemical parameters) • Is the relationship maintained in different human and natural contexts ? • Reference Thresholds based on expert judgement • What underlying concepts ? Data ? • Same criteria for all QE ? all types ?

  4. Driving forces (Agricultural land cover) Pressure - response relationship Intercalibration Phase 2 2008-2011: Rivers • The relationship between the driving forces and the biological response is dependent upon the natural and human context

  5. Intercalibration Phase 2 2008-2011: Rivers FRANCE

  6. Intercalibration Phase 2 2008-2011: Rivers NORWAY

  7. Pressures - responses relationships Intercalibration Phase 2 2008-2011: Rivers In this case, a very low biological impact can be observed with a medium level of pressures.

  8. Consequences for reference criteria (1) Intercalibration Phase 2 2008-2011: Rivers • The relationship between agricultural land cover and biological impact is highly dependent of the structure of the landscape • The relationship is poorly predictive, and cannot be easily extrapolated • Can be used as a first "filter" to select "candidate" REF sites • The relationship with artificial/urban land cover is much more reliable (REBECCA results). • Can be a valid reference criterion

  9. Consequences for reference criteria (2) Intercalibration Phase 2 2008-2011: Rivers • A very low level of pressures corresponds always to a very low biological impact : valid reference criteria. • The reverse is not always true : a very low biological impact can be encountered also with a medium level of pressures • We should not reject all the sites with a low to medium level of pressures • The validation must be done at the "stressors" level (i.e. abiotic parameters) • This supports the GIG's practical approach based on "reference" and "rejection" threshold • This could apply also to the Urban land- cover indicator

  10. Consequences for reference criteria (3) Intercalibration Phase 2 2008-2011: Rivers • The relationships between the "stressors" (i.e. abiotic parameters) and the biology is NOT dependent upon the human context. • Can we find the threshold corresponding to the beginning of the biological impact : "no-impact threshold“? • But it can vary according to the natural typology.

  11. What happens here ? ? No-impact threshold : myth or reality ? Intercalibration Phase 2 2008-2011: Rivers

  12. Intercalibration Phase 2 2008-2011: Rivers No-impact threshold : is there a conceptual model ? About 100 experts.. Allan, Barbour, Cormier, Gerritsen, Hawkins, Hughues, Karr, Larsen, Mc Cormick, Mc Intyre, Rankin, Wang, Yoder…

  13. Intercalibration Phase 2 2008-2011: Rivers Native or natural condition 1 Minimal loss of species; some density changes may occur 2 Natural Some replacement of sensitive-rare species; functions fully maintained Some sensitive species maintained; altered distributions; functions largely maintained 3 4 Biological Condition Tolerant species show increasing dominance; sensitive species are rare; functions altered 5 Degraded Severe alteration of structure and function 6 Low Increasing Effect of Disturbance [Stressor gradient] High

  14. No impact threshold Intercalibration Phase 2 2008-2011: Rivers • ICMi vs BOD5 • All CB types, France

  15. Intercalibration Phase 2 2008-2011: Rivers Large rivers - Main issues • Deep rivers in scope (non-wadeable)? • Reference values • Almost no large rivers exist in reference condition (>5000 Km2?) • IC typology limited to rivers <10,000 Km2 and reference values probably not applicable • Sampling methods • Shallow water sampling methods are inappropriate for deep waters (non-wading depth) • Survey/sampling costs could be high

  16. Intercalibration Phase 2 2008-2011: Rivers Defining reference values • Consider heavily modified and natural rivers • Check reference screening criteria for large rivers • Investigate alternative approaches for defining reference values/EQRs: • Option: Define the G/M boundary based on physico-chemistry and hydromorphology then biological community

  17. Large Rivers Typology Intercalibration Phase 2 2008-2011: Rivers • Can we define realistic reference values for EQRs (new typology?) • IC Phase 1: Some MS included deep rivers in intercalibration of RC-5 (large lowland rivers on mixed geology, 1000-10000 km2). • Are reference values for shallow water samples appropriate for deep water methods for any BQE?

  18. Loss of sinuosity (from historical reference) Intercalibration Phase 2 2008-2011: Rivers Reference Coût écologique H/G Boundary Sinuosité From Wasson et al. 1998

  19. Intercalibration Phase 2 2008-2011: Rivers Sampling • Sampling large rivers can be expensive • Consider use of other information to supplement biological data • e.g. measure of lateral freedom space in river types that should have multiple channels

  20. Intercalibration Phase 2 2008-2011: Rivers Sampling • Investigate sampling methods for deep and large rivers • Identify the biological communities that best reflect the ecological quality of large rivers • Fish (already done in Fish IC?) • Invertebrates • Phytobenthos & diatoms • Others: (eg.Riparian vegetation?)

  21. Proposed working strategy • River Steering Group provides a unified approach across all GIGs and biological quality elements (also communicate with lakes GIGs) • Intercalibration of large rivers will be undertaken by existing BQE groups of experts working across GIGs • First step are 2 papers with outline proposals (Nov 08); also a questionnaire to collect information about existing data and methods for all BQEs from all river GIGs – (ready now) • All river GIG meeting to agree detailed work programme Spring 2009

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