module 2: water budget, pressures and impacts, significant water management issues, monitoring,...
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Module 2: Water Budget, Pressures and Impacts, Significant Water Management Issues, Monitoring, Characterization Report
Hydromorphological quality elements, assessment, results
Alexei Iarochevitch
Antalya
January,15 2015
Content:
Quality elementsAssessment tools3-digits code and overall scoringDanube hydromorphological assessment (ICPDR Joint Danube Survey-3, 2013)
Quality elements supporting the biological elements
Supporting means that the values of the physicochemical and hydromorphological quality elements are such as to support a biological community of a certain ecological status, as this recognises the fact that biological communities are products of their physical and chemical environment
Hydromorphological parametersWFD requires a type specific and reference based
assessment.Based on the typology type-specific reference conditions
should be described for all main parameters (including hydromorphological).
While some parameters were derived from various historical sources (such as plainform, floodplain extent, land use), other parameters are only defined as presence or absence (degree) of human alterations, namely the amount of artificial bank material.
Quality elements for the classification of ecological status
Hydromorphological elements supporting the biological elements
Rivers
Hydrological regimequantity and dynamics of water flowconnection to groundwater bodies
River continuity
Morphological conditionsriver depth and width variationstructure and substrate of the river bedstructure of the riparian zone
EU WFD, annex 5
Quality elements for the classification of ecological status
Hydromorphological elements supporting the biological elements
Lakes
Hydrological regimequantity and dynamics of water flow residence timeconnection to groundwater bodies
Morphological conditions lake depth variationquantity, structure and substrate of the lake bedstructure of the lake shore
EU WFD, annex 5
Quality elements for the classification of ecological status
Hydromorphological elements supporting the biological elements
Transitional waters
Morphological conditionsdepth variationquantity, structure and substrate of the bedstructure of the intertidal zone
Tidal regimefreshwater flowwave exposure
EU WFD, annex 5
Quality elements for the classification of ecological status
Hydromorphological elements supporting the biological elements
Coastal waters
Morphological conditionsdepth variationstructure and substrate of the coastal bedstructure of the intertidal zone
Tidal regimedirection of dominant currentswave exposure
EU WFD, annex 5
Assessment tools
EN 14614 Water Quality – Guidance standard for assessing the hydromorphological features of rivers
EN 15843:2010 Water quality – Guidance standard on determining the degree of modification of river hydromorphology
Länderarbeitsgemeinschaft Wasser (LAWA) (Hrsg.) 2000. Gewässerstrukturgütekartierung in der Bundesrepublik Deutschland – Verfahren für kleine bis mittelgroße Fließgewässer, Berlin.
National methods (e. g. Austria, Slovakia, HYMOQ methods)
Methods of “physical habitat assessment” (hydromorphological quality elements -
HYMOQE) one of the most common methods within the EU include general description of the site, characterisation and a visual
assessment of physical in-stream and riparian habitats. tendency to define high status/reference conditions only on the basis of
presence and abundance of morphological features neglecting the river processes that generate and maintain the morphological units
methods are not comprehensive enough to adequately identify causes of hydromorphological alteration.
increasing need to improve the characterisation and analysis of the hydromorphological conditions of water bodies
EN Guidance standards (1)
Both standards (2004 and 2010) focus more on morphology than on hydrology and continuity, and on lateral and longitudinal continuity rather than on vertical continuity which is difficult to measure
Providing a method for broad-based characterization across a wide spectrum of HYMO modification of river channels, banks, riparian zones and floodplain
EN Guidance standards (2)
5 classes assessment Survey of the whole reach:
single survey: the entire reach is assessed in a single survey unit.
contiguous survey: the reach is split into a series of contiguous survey units
Categories of features for quality assessment
Category Core Subsidiary
1. Channel geometry 1a Planform
1b Channel section (long-section and cross-section) 2. Substrates
2a Extent of artificial material 2b ‘Natural’ substrate mix or character altered
3. Channel vegetation and organic debris 3a Aquatic vegetation structure 3b Extent of woody debris if expected
4. Erosion/deposition character 5. Flow
5a Impacts of artificial in-channel structures within the reach
5b Effects of catchment-wide modifications to natural flow character
6. Longitudinal continuity as affected by artificial structures
7. Bank structure and modifications 8. Vegetation type/structure on banks and adjacent land 9. Adjacent land-use and associated features 10a. Extent of floodplain not allowed to flood regularly due to engineering
10b. Constraint on lateral movement of river channel
Features assessed Score band A - Qualitative Score band B - Quantitative Guidance Examples of methods/data use
1. Channel geometry
1a: Planform(reach-based)
1 = Near-natural planform. 3 = Moderate planform changes.5 Planform changed in majority of reach, orreach completely , or almost completely, straightened.
1 = 0-5% of reach length with changed planform. 2 = >5-15% of reach length with changed planform.3 = >15-35% of reach length with changed planform.4 = >35-75% of reach length with changed change.5 = >75% of reach length with changed planform.
If possible, use absolute or recorded amounts of change rather than estimates from variety of sources. Where a river has some artificial sinuosity, but has lost its natural meandering, assign score 5. If completely straightened add note
Consult maps and compare historical with present-day planform where changes have resulted from engineering, etc. (includes loss of braiding, etc.) (1a/1b);
Engineering construction and maintenance work records (1a/1b);
Local/management personnel/expert assessment (1b);
Survey data (e.g. evidence of deepening or resectioning), structures installed (e.g. deflectors) (1b);
Knowledge of changes to width/depth ratios (1b).
1b: Channel section (long and cross)(use site and other data and combine for whole reach) If no data for 1b, the score for Channel geometry is 1a by itself. Keep two elements separate; take worse case
1 = Near-natural. No, or minimal, change in cross and/or long section. 3 = Moderately altered. Channel partially affected by one or more of the following: resectioning, reinforcement, culvert, berm, or clear evidence of dredging causing some changes in width/depth ratio. 5 = Greatly altered. Channel predominantly affected by one or more of the following: resectioning, reinforcement, culvert, berm, or clear evidence of dredging causing major change in width/depth ratio.
1 = 0-5% of reach length with changed planform. 2 = >5-15% of reach length with changed planform.3 = >15-35% of reach length with changed planform.4 = >35-75% of reach length with changed change.5 = >75% of reach length with changed planform.
Features assessed Score band A - Qualitative Score band B - Quantitative Guidance Examples of methods/data use
5. Flow 5a: Impacts of artificial in-channel structures within the reach
1 = Flow character not, or only slightly, affected by structures within the reach.3 = Flow character moderately altered.5 = Flow character extensively altered.
This feature covers the effects of artificial structures (e.g. groynes and weirs) or water abstraction on flow type diversity and sediment transport. Need hydrological data to establish relevance of discharge alterations. The effect of hydro-peaking regimes varies (e.g. according to timing of release, quantity of residual flow); this will affect scoring.
Local/management personnel/expert assessment (5a/5b);
Hydromorphological and walk-over surveys (5a);
Air photos (5a); Water resource and
operational records for water management, etc. (5b).
5b: Effects of catchment-wide modifications to natural flow character (e.g. by hydropower dams, abstractions, etc. upstream of the reach evaluated)
1 = Discharge near-natural. 3 = Discharge moderately altered. 5 = Discharge greatly altered.
Features assessed Score band A - Qualitative Score band B - Quantitative Guidance Examples of methods/data use
6. Longitudi
nal continuity
- effects of artificial
structures on migratory biota and sediment
transport
Reach-based and local impacts of sluices and weirs on ability of biota (e.g. migratory fish) to travel through reach, and sediment to be transported naturally
1 = No structures.3 = Structures present, but having only minor or moderate effects on migratory biota and sediment transport.5 = Structures that in general are barriers to all species and to sediment
Note: if barriers are large, and the reach is in the downstream part of the catchment, they may affect many other reaches upstream. On some cases fish are prevented from passing through dams even though fish passes have been installed. A score of 3 should be assigned where a dam has a fish-pass fitted that functions effectively. Where all sediment is retained behind a dam a score of 5 should be assigned even if a few species are able to pass through.
Local/management personnel/expert assessment ;
Hydromorphological and walk-over surveys;
Air photos; Fisheries personnel; Special surveys assessing
structures
3-digit code for HYMO scoring
Combine the scores for categories 1, 2, 4, 7, 8, 9, 10 to create a single score for morphology (the first of the three digits). Scores should be rounded up or down to the nearest integer (rounding up any that end in .5)
Report the score for category 5 for flow (the second of the three digits).
Report the score for category 6 for longitudinal continuity (the third of the
three digits).
For example, a code of 111 would indicate a river with the highest morphological quality, near-natural flow, and with no structures inhibiting
upstream and downstream movement of sediment and biota
Single HYMO scoring(overall assessment)
Take the mean features of the 12 scores (1, 2, 3a, 3b, 4, 5, 6, 7, 8, 9, 10a, 10b)
Round up or down to the nearest integer. Scores ending in ‘.5’ should be rounded up.
Five classesScore (Class) Name Map colour
1 Near-natural Blue
2 Slightly altered Green
3 Moderately altered Yellow
4 Extensively altered Orange
5 Severely altered Red
Three classes
Score (Class) Name Map colour
1 Near-natural Blue
3 Slightly to moderately altered Yellow
5 Extensively to severely altered Red
ICPDR Joint Danube Survey – 32013
Once per 6 yearswhole Danube from Kelheim to the delta (about 2,420 rkm):
channel, left/right banks, left/right floodplain Continuous longitudinal hydromorphological assessment of
10 rkm segments (the CEN method used in the JDS assessment are based on principle of “arithmetic mean” value both for WFD 3Digit and for the overall assessments)
Detailed site analysis by field work data, measurements, samples and assessment
Assessment scheme for WFD 3 digit continuous survey
Results for entire Danube: In general, alteration is identified (prevailing classes 3-5), in particular „Morphology“, but also the „Hydrology“. The longitudinal continuity is interrupted by 18 dams. For 2 with functioning fish passes and partial
sediment feeding (Wien-Freudenau and Melk) the value is „3“ according to CEN standard.
Longitudinal visualization of the WFD-3Digit assessment
CEN-Overall assessment
Longitudinal Visualization of the CEN- Overall assessment
Assessment “channel”
Assessment “banks” (left and right bank)
Assessment “floodplains” (left and right floodplain)
Danube WFD-3Digit assessment
HYMO 2-classes assessment, Tisza RBD, Ukraine
Thank you for attention!
Bismil, GAP, 2010
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