Typology of surface waters is not a new invention…

1. Introduction to the development of the German typology of surface waters and definition of reference conditions Mario Sommerhäuser Emschergenossenschaft – Lippeverband

2. Typology of surface waters is not a new invention… „Aquae sunt talis qualis terra per quam fluunt.“Plinius the Elder, Naturalis historia, Book 31, § 52, Z. 5

3. The typology of surface waters • For about 100 years (classification of lakes) • Idea: to classify the large variety of natural water bodies to more simple and applicable units • From individual water bodies to the idea of types: Lowland streams, Mountain streams …, Sandy streams, Gravel bed streams … • Now essential part of the philosophy of the WFD

4. Demandsof the WFD Why is typology so important? Base for most of the further steps: • Definiton of type-specific reference conditions • Development of type-specific assessment systems • Designation of water bodies • Type-specific sensitivity against different stressors • Program of measures has to care for type-specific features of water bodies

5. Decisions needed for typology WFD - Annex II: System A or System B? • Same obligatory factors are used in both (geographic position, altitude, size, geology) • System A prescribes categories for these factors, and ecoregions for the spatial aggregation of the types=> types remain rough and often do not reflect reality • System B has no prescriptions, permits additional factors; => types more flexible, reflect reality

6. Methodological approaches Top down approach Abiotic features Similarity analyses River types Expert opinions Biocoenoses, e. g. MZB Bottom up approach

7. Advantages and disadvantages of Top down / Bottom up approach Top down approach… • only few abiotic data needed • not necessarily biological meaningful (types have to be validated) • time-saving (development: weeks – months) Bottom up approach … • huge biotic and abiotic data sets from reference sites needed • depends on availability of data and quality of sites • biologically meaningful, reference conditions implied • time-consuming (up to several years…)

8. Example: Stream typology Germany Philosophy: • one typology for the whole country and all quality components (macrophytes, algae, MZB, fish) • „as many types as necessary, as few as possible“ • scientifically sound and politically reasonable • simple approach (start: top down, validation: bottom up) • biologically meaningful • System B

9. Obligatory parameters:- Ecoregion (Illies 1978)- Geology (Ca, Si, Org)- Size basin size classes 10 - 100 km² 100 - 1 000 km² 1 000 - 10 000 km² > 10 000 km²(acc. System A) Optional parameters:- Sub-ecoregions (aquatic land- scapes): more differentiated geology (granite, moraines…) valley form slope- dominant substratum (river bed material)(acc. System B) Parameters  Clearly a „B-typology“.

10. Step 1: “Ecoregions” Illies(1978) 3 Ecoregions: 4: Alps 9: Lower Mountains 14: Lowlands

11. Step 2: Sub-ecoregions • about 40 ‚aquatic landscape units ‘ (=sub-ecoregions) • homogeneous regions for certain stream types • based on geo- morphology

12. Step 2: Sub-ecoregions Definition of sub-ecoregions (aquatic landscapes) • homogeneous regions with respect to the characters of surface waters (due to geology, soils, relief…) • main distribution areas of certain surface water types, but different types can occure e. g. due to changes in longitudinal zonation • can be depicted in maps for orientation

13. Step 2: Sub-ecoregions • „Super-Parameter“ • integration of many typological relevant parameters as geology, soils, relief, valley sh apes, slope… • important for the drawing of GIS maps of stream types

14. + Longitudinal Zonation (biocoenotic type) Aggregated sub-ecoregions (base type) Step 3: Aggregation of sub-ecoregions Step 4: Longitudinal zonation

15. Biocoenotic analysis of whole Germany (ecoregions) Biocoenotic analysis of several 1000 data sets up to now (best available sites, most of them preclassified as „very good“ or „good ecological status“) Step 5: Biological validation

16. NMS_EPTCOM_gen_total_20.11.2002; Stress: 0,285 Lowlands Achse 2: 32,0 % Ökoregion Alpen Voralpen Mittelgebirge Tiefland Achse 1: 41,8 % • „non-metric multidimen-sional scaling“ (NMS) • Ordination diagram: similiar data sets (sites) are close together, different data sets are apart NMS „Germany “ Lower Mountains/(Pre)Alpine area

17. Typ 20 Typ 15 Typ 11 Typ 17 Typ 14 (+13) Typ 16 NMS Lowlands: biocoenotic stream types

18. Product I: Typology and Types Table of 25 biocoenotic relevant stream types for Germany

19. Product I: Typology and Types 25 stream types: 4 types for the Alps and the Alpine foothills 8 types for the Central highlands 9 types for the Central lowlands 4 „Ecoregion-independent“ types

20. Product II: Map of stream types (GIS) • depiction of stream types as digital map • base: WFD-relevant river network • short description of the types („passports“) serve as a legend for the map

21. Product II: Map of stream types (GIS)

22. Typ 1: 6% Typ 19: 9 % Typ 16: 4 % Typ 5: 17 % Typ 15: 5 % Typ 5.1: 7 % Typ 14: 11 % Typ 9: 5 % Typ 6: 8 % Typ 7: 5 % Product II: Map of stream types (GIS) Most common stream types of Germany: Type 5: Small coarse substrate dominated, siliceous highland rivers (17 %) Type 14: Small sand dominated lowland rivers (11 %) Type 19: Small streams in riverine floodplains (9%)

23. Product II: Map of stream types (GIS) Common stream type of the Ecoregion 4 Alps: Type 1: Alpine streams(95 %) Common stream type of the Ecoregion 9 (8) Central Highlands: Type 5: Small coarse substrate dominated siliceous highland rivers (28 %) Common stream type of the Ecoregion14 Central plain: Type 14: Small sand dominated lowland rivers (28 %)

24. Product III: Type descriptions as passports Morphological features: „... very distinct stream type... , winding to meandering in unregular arches in a U-shaped valley, ... naturally most deep cut stream type. Water often cloudy due to natural erosion of fine minerally particles from the bottom (clay, loam, loess).“ Biocoenoses: Macrophytes and Phytobenthos: „... aquatic flora only rarely to be found due to cloudy water. Mainly float leaf plants occuring e. g. Potamogeton pectinatus...“ Remarks: „... nowadays almost completely destroyed, due to intense land use in fertile loess areas.“ Available in English: www.wasserblick.net or the HR Twinning website Substratum: „... dominant fine minerally particles (clay, loam, loess), organic materials rarely to be found, often aggregations of particles to slab, marl ...“

25. combinations Reference conditions • comparable to high ecological status, (= no or only minimum deviance from undisturbed conditions in hydromorphology, water qualiy and biocoenoses) • starting point of assessment! Basis best available surface waters modelling, reconstruction historical data

26. Criteria for reference conditions (AQEMconsortium 2002, REFCOND toolbox) • Land use : Influence of urbanisation, land use and forest management should be as low as possible Morphology and stream habitats • Floodplain at reference site: natural climax vegetation, extensive forests • no migration barriers • no removal of coarse woody debris • no bank and bed fixation

27. Criteria for reference conditions Hydrology and regulation • no alteration of natural regime • no or only minor alteration of hydrology by dams, reservoirs, weirs, or sediment retaining structures • no water abstraction etc. Especially for large rivers and in the lowlands: impossible! Water quality • no point-source pollution • no point-source eutrophication • no acidification • no alteration of thermal regime • no salinisation • no toxic substances

28. 1. Data base of near-natural rivers or river stretches

29. 2. Historical data: example River Ems 1850-2000

30. Sandy habitats at the stream margins: Ephemera danica several Leptoceridae Wood accumulations: Macronychus quadrituberculatus Potamophilus acuminatus Stenelmis canaliculata Abandoned channels and floodplain ponds: Siphlonurus aestivalis Several Dytiscidae, Haliplidae, Gyrinidae 3. Reconstruction, modelling: River Sieg, 1822

31. Conclusions: stream typology of Germany • top down typology acc. to System B has been developed by expert opinion (integration of existing regional typologies) • base of typology: map of aquatic landscapes (sub-ecoregions) • biocoenotic validation: data base from existing data sets and new collected data has been compiled afterwords • typology could ± be validated „bottom up“ with these data sets • GIS map of stream types has been designed • types have been described in passports • typology as living document and iteration: can be updated in future • accepted by scientific projects and legislation

32. Thank you for your attention!

33. Costs and time needed • typology acc. to System B: some months / 0 € (national experts) • map of aquatic landscapes (sub-ecoregions): 3 years / 75,000 € (private company)!!! hint: map was too detailed, can be developed much faster /~ 40,000 € • biocoenotic validation: ongoing process since 4 years / ~ 60,000 € (scientific institute)!!! hint: data can be collected within the monitoring • GIS map of stream types: 1 year / 60,000 € (private company) • passports: some months / 0 € (national experts)

34. Informations needed for typologies of surface waters (acc. to System B) • rough differentiation of the country and the regions (eco- regions, altitude, size classes, geology, e. g. acc. System A) • (digital) maps of surface waters, geology, soils, topography, relief/altitude lines, borderlines of ecoregions; historical maps • selection of relevant optional parameters for the definition of biocoenotic meaningful types - maybe different for the (sub-)ecoregions • (if available:) data sets of reference sites (abiotic and biotic data) • interdisciplinary experts who know their country and ist surface waters !

35. Examples of stream typologies from neighbor countries typologies of neighbor countries differ due to different abiotic conditions and slightly different methods

36. Examples of stream typologies from neighbor countries • usually System B was chosen, parameters were partly different • in medium sized and large countries number of types varies between 20–30