The Role of Hydromorphology in WFD. The Relation of Biology and Hydromorphology

European Union Water Initiative plus
for Eastern Partnership
© iStockphoto.com/ansonsaw
Support of Water Policy Reforms
towards Integrated Water Resources Management
WORKSHOP ON
ECOLOGICAL CLASSIFICATION
The Role of Hydromorphology in WFD
The Relation of Biology and Hydromorphology
Karin Deutsch/Gisela Ofenböck
Kyiv, 19-20 June 2018

HYMO ASSESSMENT IS RELEVANT FOR …
Typology
Pressure &impact
analysis
Development of
status classification
Water body
delineation
Programme of
measures
HMWB
designation
Definition of good
ecological
potential
Monitoring
Gap-Analysis
Design of appropriate
restoration measure
Risk analysis

HYMO ASSESSMENT RELEVANT FOR …
Typology
Pressure &impact
analysis
Development of
status classification
Water body
delineation
Programme of
measures
HMWB
designation
Definition of good
ecological
potential
Monitoring
Gap-Analysis
Design of appropriate
restoration measure
Risk analysis

Hydromorphology and WFD: Quality Element
Water Framework Directive, Annex V – Normative definitions:
Rivers
 Biological elements
 Composition and abundance of aquatic flora
 Composition and abundance of benthic invertebrate fauna
 Composition, abundance and age structure of fish fauna
 Hydromorphological elements supporting the biological elements
 Hydrological regime
quantity and dynamics of water flow
connection to groundwater bodies
 River continuity
 Morphological conditions
channel patterns, river depth and width variation
flow velocities, substrate conditions,
structure and condition of the riparian zone
 Chemical and physico-chemical elements supporting the biological elements
Correlated
with condition
of biological
QE

Hydromorphology as a Quality Element according WFD
Water Framework Directive, Annex V (Normative definitions of ecological status classifications):
Definition of High, Good and Moderate Status for Hydromorphological Quality Elements of Rivers
Element High status Good status Moderate status
Hydrological
regime
The quantity and dynamics of
flow, and the resultant
connection to groundwaters,
reflect totally, or nearly totally,
undisturbed conditions.
Conditions consistent with the
achievement of the values
specified above for the
biological quality elements.
River continuity
The continuity of the river is
not disturbed by anthropogenic
activities and allows undisturbed
migration of aquatic organisms
and sediment transport.
Morphological
conditions
Channel patterns, width and
depth variations, flow velocities,
substrate conditions and both the
structure and condition of the
riparian zone correspond totally
or nearly totally to undisturbed
conditions.

HYMO DATA NEEDED FOR…
Definition of typespecific reference conditions &
high status class
• hydromorphological characteristics
(e.g. width, depth, slope, shape of river bed, substrate,
discharge,…)
• physico-chemical conditions
• and the related aquatic communities (biological quality
elements)
… description of undisturbed conditions
High status
range from undisturbed conditions to nearly undisturbed
conditions

HYMO Assessment needed for…
Calibration of biological classification methods
Need of site selection with graded pressures/altered hymo
conditions to prove correlation with condition of (pressure
sensitive) BQEs
scale: site/segment
…. to be able to derive a 5 classes assessment system for biological
QE

Surface Water body (CIS Guidance No 2): a discrete and significant element
of surface water - „Management Unit“
– to which the environmental objectives must apply
(compliance checking unit)
– enable the status to be accurately described and compared to
environmental objectives
…within water body : uniform reference conditions
and uniform status/conditions
scale: site/segment
Interlinkage pressure /altered conditions – impact- ecological status
HYMO Assessment needed for…
Water body delineation

CIS GUIDANCE No 2 - IDENTIFICATION OF WATER BODIES
However, identifying water
bodies that will provide for an
accurate description of the
status of surface water … will
require information from the
Art. 5 analyses and reviews,
and the Art. 8 monitoring
programmes.

Pressure/
impact
information
as a
surrogate
for status
information

Water Body Delineation
Detailed delineation according to pressures
Pressures eg water
abstraction, continuity
interruptions
Waterbody Type x
Waterbody
1
Waterbody
2
Exact localisation of pressures
/altered conditions is crucial
for water body delineation

• Identification of significant hydromorphological pressures
→ several levels of alteration intensity
(at least 3 levels:
• no pressure
• pressure but not significant
• significant pressure
scale:
site/segment
Pressure and impact analysis (Art. 5 WFD)
= Alterations of hymo conditions

Pressure/ impact information aggregated for a water body:
At least 2 classes required: 1- not at risk, 2- at risk
Most common 3 grades:
1 – at risk, 2 – possibly at risk, 3 – not at risk
(more appropriate to streamline monitoring for status assessment;
easy to add 4th grade: „no risk at all“ as there is no pressure )
scale: water body
Risk assessment

Wb has to be substantially changed in character
→ knowledge needed on the grade of hydromorphological alteration:
to proof that hydromorphology is altered to such an extent that the wb is not only
significantly impacted by hymo pressures but even changed in character - being the
reason that bological QE are failing good status
Changes in hydromorphological charcteristics for achieving GES (=restoration
measures) would have a significant adverse effect on use(s) or wider environment
(Art. 4.3. WFD)
→ possible restoration measures (physical alterations) to achieve GES and their
effect on use can only be defined, when detailed information on hydromorphological
pressure(s) and the causing driver(s) is known.
HMWB designation

HMWB delineation

Status assessment:
Site/segment information is needed for selection of
representative monitoring site(s)
Monitoring

Koller-Kreimel/ BMLFUW VII 1
EXAMPLE: MORPHOLOGICAL ALTERATIONS (SEGMENTS) -
HIGH VARIATION OF ALTERATIONS
Where to set representative monitoring
site?

EXAMPLE: HYDROLOGICAL PRESSURES AND MIGRATION
BARRIERS –HIGH VARIATION OF PRESSURES
Reduced
flow
Migration barrier
Impound-
ment
Where to set representative
monitoring site ?

Detailed info on hymo pressures/impacts (exact location/ segment
magnitude/extent, …) allows:
• calculation of restoration costs on an overview level
• Allocating clear identification of the „causer“
• assessment of magnitude of possible negative effects on use (i.e. loss in
electricity generation)
… also relevant for HMWB designation, exemption
• Selection of the most cost-effective set of measures
Development of PoM/ design of technical restoration
measures

FRAMEWORK CONDITIONS FOR
METHOD SELECTION

WHAT TO BE TAKEN INTO ACCOUNT?
Manageability
 applicability on whole river net
 affordability (costs: time, manpower, equipment, …)
 reproducibility of assessment results (variation between
groups, clear criteria/decisions)
 easy to be updated

Efficiency
• Appropriate level of information/details required
• Make use of existing data / synergies
As simple as possible
&
as detailed as necessary!

Appropriateness & effectiveness
 Scale
 Parameter
 Independent from water body size
 Assessing the degree of deviation from typespecific reference conditions
 Is the method suitable for identification of variation of different pressures and
their level of intensity within a water body?
 Parameter with clear correlation with biology

THE RELATION OF BIOLOGY AND
HYDROMORPHOLOGY
Gisela Ofenböck
Federal Ministry for Sustainability and Tourism
gisela.ofenboeck@bmnt.gv.at

BACKGROUND
Hydromorphological processes create and shape different river types
(habitat diversity, river bed and bank dynamics,…)
Organisms are adapted to specific habitats , e.g.
 size of substrate: lithic fauna, sand fauna,…
 flow velocity: rheophilic, stagnophilic,
 …
Water body types can be described using
 abiotic factors (hydromorphological conditions and physico-chemical conditions) and
 biotic factors (aquatic communities, taxonomic composition, metrics,…)
 reference conditions for ecological status assessment

BACKGROUND
 Hydromorphological alterations cause mainly a loss of habitats or habitat diversity.
 The degree of habitat loss is reflected in the loss of fauna and leads to
 Reduced number of species
 Reduced number of sensitive species and habitat specialists
 Reduced diversity
 the higher the hymo-alteration, the more biology deviates from typespecific reference
conditions
 Possible cumulative effects can be detected by diverse sensitivity of organism groups

BACKGROUND
EXAMPLE: IMPOUNDMENT
… anthropogenic pressure changes
 hydromorphological conditions, e.g.
 flow velocity: decrease
 Substrate: decrease in size: (large stones  stones  gravel
 fine gravel  sand  silt)
 habitats
macrolithal  mesolithal  microlithal  akal  psammal  pelal
 diversity of habitat (decrease in number of habitats)
 aquatic communities: change in species composition
 ecological status: assessment: deterioration of status

Detailed risk assessment helps in
 Design of target-oriented and cost-effective monitoring system
 Status assessment (grouping of information!)
 Predict the effect of new projects/measures!
RISK ASSESSMENT
Identification of significant hydromorphological
pressures such as
• River straigthening/regulation
• Transversal structures/ obstacles
• Impoundments /reservoirs
• Water abstraction
• Hydro peaking
Knowledge on
hydromorphological
conditions
is crucial for risk
assessment!
= Likelihood, that a water body will fail to achieve the environmental objectives
of the WFD (good status!) due to the impact resulting from significant
pressures

RISK ASSESSMENT NEEDS
 Knowledge on hydromorphological conditions
(graded assessment system!)
 Knowledge on relationship between hydromorphological
conditions/alterations and biological response
changing habitats  changing aquatic community
 Close cooperation between experts on hydromorphology &
biology!

RISK ASSESSMENT – WHAT IS NEEDED?
Describe effect of hymo-pressures to
 habitats and
 habitat diversity
= Alterations to hydromorphological
conditions
 Classified hymo pressure information
according to significance
- Water abstraction (5 classes)
- Morphological alterations (5 classes)
- Impoundments (length of impoundment)
- River continuity (3 classes)
 risk assessment in classes
+
+
=

HYMO-SENSITIVE
ASSESSMENT METHODS

AUSTRIAN ASSESSMENT METHODS
GENERAL APPROACH: RIVER TYPE SPECIFIC AND STRESSOR SPECIFIC
organic pollutionhydromorphological alterations
(impoundment, channelisation, hydropeaking, water
abstraction,…
nutrient pollution

BIOLOGICAL SENSITIVITY
Phyto-
benthos
Makro
phytes
Makrozoo-
benthos
Fish
Changes in water quality
Nutrients/ eutrophication +++ ++ ++ +
Oxygen regime/ Organic pollution + + +++ ++
Temperature + + ++ +++
Salinity ++ ++ ++ ++
Acidification + ++ +++ ++
Hydromorphological changes
Morphological alterations (m.a.) + + ++ +++
m.a. only river bed/soil fixation + + +++ ++
Water abstraction/ residual flow + ++ ++ +++
Flow fluctuations (hydropeaking) + ++ ++ +++
Impoundment + ++ +++ ++
Migration barriers ++ +++

KEY FACTORS
 TYPOLOGY REFLECTS BIOLOGY
keep variation in reference conditions as low as possible, BQE specific
typology
 INFORMATION ON HYDROMORPHOLOGICAL ALTERATIONS
preclassification of sites, metric selection, testing
 MULTI-METRIC INDIZES
stressor specific metric composition, typespecific metric composition
 AVOID ADDITIONAL VARIATION
(standardised methods, quality assurance,…)

…A GOOD TYPOLOGY
 Water body types are the basis of the classification system
describe reference conditions
Biological communities define the types not the other way round!
 Typology needs to reflect the biological conditions
 the metrics cannot distinguish between natural variation and anthropogenic stressors  if
variation in reference conditions is to high, assessment method will not work
 System A/B typology is not enough – types have to be tested with biological data
 It might be necessary to define different types for different BQEs!
Different parameters and level of detail, e.g. PHB requires less types than fish or benthic
invertebrates

…INFORMATION ABOUT HYMO PRESSURES
Describe effect of hymo-pressures to
 habitats and
 habitat diversity
= Alterations to hydromorphological conditions
Classified hymo pressure information
according to significance
- Water abstraction
- Morphological alterations
- Impoundments (e.g. length of impoundment)
- River continuity
Use existing hydromorphological surveys and expert judgement
Sites used for method development were preclassified to 5
status classes

Use preclassified sites to test metrics and MMI
 Reference sites
 used for definition of reference conditions
 Whole Range of sites
 used for selection of metrics (testing reaction to pressure)
 Sites in the range of good/moderate
 used for testing plausibility of results (need for action?)
 Poor/bad: „clear-cut-situations“
METRIC SELECTION AND TESTING Non-Outlier Max
Non-Outlier Min
75%
25%
Median
Bioregion: Hungarian Plains
Ecological Quality Class
#EPT-Taxa
-2
2
6
10
14
18
22
26
30
5 4 3 2 1
Non-Outlier Max
Non-Outlier Min
75%
25%
Median
Bioregion: Granite-Gneiss Region
Ecological Qualitiy Class
#sensitivetaxa
-2
2
6
10
14
18
5 4 3 2 1
Non-Outlier Max
Non-Outlier Min
75%
25%
Median
Bioregion: Hungarian Plains
Diversity(Margalef)
2
4
6
8
10
12
14
5 4 3 2 1
Non-Outlier Max
Non-Outlier Min
75%
25%
Median
Bioregion: Granite-Gneiss Region
#TotalTaxa
0
20
40
60
80
100
120
140
5 4 3 2 1

CLEAR-CUT CRITERIA
Significant impact - effect of hymo alteration is well known:
 effect is obvious
 research studies
 monitoring experience
 expert knowledge of biological effects…
 Water abstraction: Water abstraction with no residual flow regulations or
river stretch is permanently or temporarily falling dry
 Large impoundments or chain of impoundments
Reduced flow velocity  changed substrate and oxygenation conditions impact on benthic invertebrates
research study: at least 50% is failing good status, increases with length of impoundment
 Hydro peaking: Amplitude > 1:5
 Morphology: banks are totally anthropogenically altered,
no formation of natural bank structures, river is cased
Most methods will detect effects of extreme pressures!
NO MONITORING NECESSARY!
class 4 class 5

…MULTI-METRIC-INDIZES
 Response of metrics to different pressures – might react in opposite
directions!
Rhithron-Feeding type-Index (RETI)
(% shredders and grazers related to detritus feeders and filterers)
Decreases with organic pollution or impoundment
Increases with channelisation (Rhitralisation)
Why? No habitats for detritus feeders, no food
% EPT-Taxa will increase
 An index that detects organic pollution/impoundment will maybe not detect
effects of channelisation
 different metrics/metric composition needed!
AN ALL-IN-ONE-DEVICE THAT FITS EVERY PURPOSE?

Biological Quality
element
Hydromorphol.
pressures
Nutrients Organic pollution
Acidifi-
cation
Macro-invertebrates +++ ++ +++ ++
General Degradation
(Multi-Metric Indices)
Nutrient Pollution and „Potamalisation“
Species Richness/Diversity (loss of habitats,
species deficiency) „Rhithralisation“
Saprobic Index
(typespecific)
Acidification
Index
(Braukmann &
Biss)
4 separate Indices
Example: Austrian method for benthic Invertebrates

AUSTRIAN METHOD FOR BENTIC INVERTEBRATES
MMI –“Potamalisation“ MMI – „Rhithralisation“
Nutrient pollution
Impoundment
Siltation
Water abstraction
Nutrient pollution
Habitat degradation
(e.g. channel straightening,
stream bed construction,
sanding,…)
Hydropeaking
Toxic substances
Alien species
 2 separate MMIs cover 2 main pressure situations:
Includes only metrics that
react to habitat degradation
explicitely in one direction
“Species
Richness/Diversity
Index”

 use standardised sampling methods (e.g. MHS)
 define appropriate sampling period
(taxonomic determination e.g. benthic invertebrates larval stages)
 use standardised taxa lists, identification keys,…
 quality assurance: training courses, controls, validation of results…
…AVOID ADDITIONAL VARIATION

THANK YOU!

The Role of Hydromorphology in WFD. The Relation of Biology and Hydromorphology

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to The Role of Hydromorphology in WFD. The Relation of Biology and Hydromorphology

Similar to The Role of Hydromorphology in WFD. The Relation of Biology and Hydromorphology (20)

More from EU Water Initiative plus for Eastern Partnership

More from EU Water Initiative plus for Eastern Partnership (20)

Recently uploaded

Recently uploaded (20)

The Role of Hydromorphology in WFD. The Relation of Biology and Hydromorphology