Functioning and values of streams

Transcription

1 Functioning and values of streams Flow regimes and ecological functioning Difference between perennial, intermittent and ephemeral streams The ecological relevancy of hydrological regimes Characterisation according to the EU Water Framework Directive Environmental and ecological flows Emek Hefer January J.L.Fiselier Royal HaskoningDHV

2 Perennial, intermittent and ephemerial streams Stream ecology is determined by water The major difference between rivers is determined by its hydraulic regime: Perennial rivers: permanently flowing Flow and floods Intermittent rivers: flowing most of the time Pools and soil moistures Ephemeral rivers: flowing occassionally Groundwater 2

3 Perennial, intermittent and ephemerial streams Presence in Israel and classification All types are present in Israel, albeit strongly modified and many perennial streams have been lost. nalysis 3

4 Perennial, intermittent and ephemerial streams All types are present in Israel, albeit strongly modified and many perennial streams have been lost. nalysis 4

5 Perennial rivers Flow regimes and ecological functioning

6 Perennial rivers Examples in Israel Jordan river Kishon river 6

7 Perennial streams Flood and baseflows of perennial streams Hydrological characteristics High flows Elevated flows Baseflow Floods Baseflow Floods Timing Mediterrean streams Floods in winter Baseflow in summer Rain-runoff Groundwatersprings Rain-runoff Spring-fed baseflows 7

8 Perennial streams High oxygen and rheophile species Ecological characteristics High flows Elevated flows Baseflow Floods Flow leads to higher oxygen levels, connectivity, gradients in food material, stability in habitats. Rheophile species Interaction with estuary mouths 8

9 Perennial streams Flood and baseflows of perennial streams Ecological relevancy Migration of fish Flooding of floodplains Recharge of groundwater Connectivity and refuges on baseflow 9

10 Perennial rivers Important concepts for perennial rivers Mainly based on the presence of fish 10

11 Perennial rivers in the WFD From effluent standards, to specific ecological objectives The EU Water framework directive is foremostly directed at perennial rivers Effluent standards related to flow classes Physical-chemical parameters Effluent standards related to good status In water quality standards based on stream ecology System related physicalchemical parameters Non-system priority and toxic substances Ecological parameters, algae, macro-fauna, vegetation and fish 11

12 Perennial rivers in the WFD Classification and objectives within the WFD framework Distinction of natural water types Conditioning factors en characterisation Delineation of water bodies Designation of water bodies Geology Climate Hydrology and morphology Water quality and priority substances Size Vegetation Macroinvertebrates, fishes

13 Perennial rivers in the WFD Classification and objectives within the WFD framework Distinction of natural water types Delineation of water bodies Designation of water bodies Conditioning factors en characterisation Boundaries Geology Hydrology and morphology Types Climate Water quality and priority substances Priority areas Size Vegetation Major modifications Macroinvertebrates, fishes Major point pollution sources 13

14 Perennial rivers in the WFD Classification and objectives within the WFD framework Distinction of natural water types Delineation of water bodies Designation of water bodies Conditioning factors en characterisation Geology Hydrology and morphology Boundaries Types Status Natural Climate Water quality and priority substances Priority areas Heavily modified Size Vegetation Major modifications Artificial Macroinvertebrates, fishes Major point pollution sources 14

15 Perennial rivers in WFD Classification and objectives within the WFD framework Delineation of waterbodies Objectives of waterbodies Minimum status for each characteristic Types Close to reference conditions Optimum Priority areas Nature areas that depend on water Additional objectives Good Fish/shellfish water Bathing water Nitrate directive/drinking water Additional objectives Moderate Bad 15

16 Perennial rivers in the WFD Guidance documents Ecological aspects and characterisation Delineation and designation Economic analyses and financing Monitoring and intercalibration Planning and public participation 16