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

Rivers Intercalibration Phase 2 Key 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. Reference conditions We need to:.

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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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