SIST-TP CEN/TR 16151:2011

Water quality - Guidance standard on the design of Multimetric Indices

This document describes methods for developing and applying Multimetric Indices used for assessing rivers, lakes, transitional waters or wetlands. It is suitable for use with data on fish, benthic invertebrates, macrophytes, phytoplankton, and phytobenthos.

Wasserbeschaffenheit - Anleitung zur Planung und Erstellung Multimetrischer Indices

Dieses Dokument beschreibt die Verfahren zur Entwicklung und Anwendung Multimetrischer Indices zur Bewertung von Fließgewässern, Stillgewässern, Übergangsgewässern und Feuchtgebieten. Es ist geeignet zur Verarbeitung von Daten zu Fischen, benthischen Invertebraten, Makrophyten, Phytoplankton und Phytobenthos.

Qualité de l'eau - Norme de recommandations relatives à la conception des indices multimétriques

Kakovost vode - Navodilo za načrtovanje multimetrijskih indeksov

Ta dokument opisuje metode za razvijanje in uporabo multimetrijskih indeksov, ki se uporabljajo za ocenjevanje rek, jezer, somornic in mokrišč. Primeren je za uporabo skupaj s podatki o ribah, bentoloških nevretenčarjih, makrofitih, fitoplanktonu in fitobentosu.

General Information

• Status: Published
• Publication Date: 03-May-2011
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: KAV - Water quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 08-Apr-2011
• Due Date: 13-Jun-2011
• Completion Date: 04-May-2011
• Ref Project: CEN/TR 16151:2011 - Water quality - Guidance on the design of Multimetric Indices

Standards Content (sample)

SLOVENSKI STANDARD
SIST-TP CEN/TR 16151:2011
01-junij-2011
.DNRYRVWYRGH1DYRGLOR]DQDþUWRYDQMHPXOWLPHWULMVNLKLQGHNVRY
Water quality - Guidance standard on the design of Multimetric Indices

Wasserbeschaffenheit - Anleitung zur Planung und Erstellung Multimetrischer Indices

Qualité de l'eau - Norme de recommandations relatives à la conception des indices

multimétriques
Ta slovenski standard je istoveten z: CEN/TR 16151:2011
ICS:
13.060.45 Preiskava vode na splošno Examination of water in
general
SIST-TP CEN/TR 16151:2011 en,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST-TP CEN/TR 16151:2011
---------------------- Page: 2 ----------------------
SIST-TP CEN/TR 16151:2011
TECHNICAL REPORT
CEN/TR 16151
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
April 2011
ICS 13.060.45
English Version
Water quality - Guidance on the design of Multimetric Indices

Qualité de l'eau - Lignes directrices pour la conception des Wasserbeschaffenheit - Anleitung zur Planung und

indices multimétriques Erstellung Multimetrischer Indices

This Technical Report was approved by CEN on 27 December 2010. It has been drawn up by the Technical Committee CEN/TC 230.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16151:2011: E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST-TP CEN/TR 16151:2011
CEN/TR 16151:2011 (E)
Contents Page

Foreword ..............................................................................................................................................................3

Introduction .........................................................................................................................................................4

1 Scope ......................................................................................................................................................5

2 Terms and definitions ...........................................................................................................................5

3 Principle ..................................................................................................................................................6

4 Procedure ...............................................................................................................................................7

4.1 General ....................................................................................................................................................7

4.2 Selection of Candidate Metrics ............................................................................................................8

4.3 Exclusion of redundant metrics ...........................................................................................................8

4.4 Definition of Upper and Lower Anchors ..............................................................................................8

4.5 Transformation into a 0 to 1 score .......................................................................................................9

4.6 Selection of core metrics ......................................................................................................................9

4.7 Combination of Core Metrics to a Multimetric Index indicating a single stressor or

indicating general degradation (general multimetric approach) ......................................................9

4.8 Combination of Core Metrics to a Multimetric Index separating the impact of different

stressors .............................................................................................................................................. 10

Annex A (informative) Examples for metrics used to assess individual Biological Quality

Elements, assigned to metric types.................................................................................................. 11

Bibliography ..................................................................................................................................................... 12

---------------------- Page: 4 ----------------------
SIST-TP CEN/TR 16151:2011
CEN/TR 16151:2011 (E)
Foreword

This document (CEN/TR 16151:2011) has been prepared by Technical Committee CEN/TC 230 “Water

analysis”, the secretariat of which is held by DIN.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

---------------------- Page: 5 ----------------------
SIST-TP CEN/TR 16151:2011
CEN/TR 16151:2011 (E)
Introduction

Multimetric Indices are among the commonly used tools for classification of the quality of fresh water and

brackish water ecosystems (rivers, lakes, transitional waters, wetlands). A Multimetric Index combines several

individual metrics, the results of which are finally combined into a Multimetric result. Thus Multimetric Indices

integrate several attributes of a community (“metrics”) to describe and assess condition. Different categories

of metrics (e.g. taxa richness, share of sensitive and tolerant species, trophic structure) reflecting different

environmental conditions are combined into one Multimetric Index.

Multimetric Indices can be applied to different aquatic ecosystems (rivers, lakes, transitional waters, wetlands)

and to different Biological Quality Elements (fish, benthic invertebrates, macrophytes, phytoplankton,

phytobenthos). They are flexible in terms of the composition of metrics, since different metrics are suited for

the assessment of different ecosystems or different stressors.

In recent years, a wide variety of Multimetric Indices has been developed and is now being applied,

particularly for the purpose of implementing the Water Framework Directive. It can be expected that many

existing Multimetric Indices will be adapted and many new ones will be developed within the next years. To

enhance comparability between Multimetric assessment systems the procedure of developing and applying a

Multimetric Index is described.
---------------------- Page: 6 ----------------------
SIST-TP CEN/TR 16151:2011
CEN/TR 16151:2011 (E)
1 Scope

This document describes methods for developing and applying Multimetric Indices used for assessing rivers,

lakes, transitional waters or wetlands. It is suitable for use with data on fish, benthic invertebrates,

macrophytes, phytoplankton, and phytobenthos.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
Anchors (Upper and Lower Anchors)

values of a metric, which are empirically set and defined as “1” (Upper anchor) and “0” (Lower anchor),

respectively, for transferring a metric’s result into a 0 to 1 score

NOTE The Upper Anchor relates to the reference value (i.e. the metric’s value under reference conditions). The

Upper Anchor can be calculated from the median or mean of reference samples or by other appropriate statistical

methods as described in 4.3.

The Lower Anchor is related to the lower limit of the metric’s value under the worst ecological quality conditions.

2.2

fresh water or brackish water type (river type, lake type, transitional water type)

division into an ecologically meaningful entity of sites with limited biotic and abiotic variation and a

recognisable discontinuity with other types

NOTE Fresh water or brackish water types serve as “units“, to which an assessment system can be applied.

2.3
metric

measurable part or process of a biological system empirically shown to change in value along a gradient of

human influence [2]

NOTE It reflects specific and predictable responses of the community to human activities, either to a single factor or

to the cumulative effects of all events and activities within a watershed.
2.4
metric type

metrics addressing comparable aspects of a community, regardless of the stressor to which the metrics are

responding
NOTE The following metric types can be distinguished (see Annex A):

− composition / abundance metrics: all metrics giving the share of a taxon or taxonomic group in relation to the total

number of individuals counted; all metrics giving the abundance of a taxon or taxonomic group; metrics

comparing reference and observed taxa (e.g. similarity indices);

− richness / diversity metrics: all metrics giving the number of taxa within a certain taxon (including the total number

of taxa), all diversity indices;

− sensitivity / tolerance metrics: all metrics giving the ratio of taxa sensitive and insensitive to stress in general or to

a certain stress-type, either using presence/absence or abundance information;

− functional metrics: all metrics addressing the characteristics of taxa other than their taxonomic definition

(biological or ecological traits, ecological guilds): feeding types, habitat preferences, ecosystem type preferences,

current preferences, life-history parameters, body-size parameters; they can be based on taxa abundance or

richness.
---------------------- Page: 7 ----------------------
SIST-TP CEN/TR 16151:2011
CEN/TR 16151:2011 (E)
2.5
Multimetric Index
combination of the results of three or more metrics
2.6
stressor

category of direct or indirect human impact to a fresh water, which potentially influences the composition and /

or abundance of stream biota
NOTE The following stressors can be distinguished:
− organic pollution: organic matter input induced by human activities;
− eutrophication: nutrient input induced by human activities;

− acid stress: permanently or temporarily decreased pH value due to human activities;

− temperature stress;
− toxic stress: effects of toxic contaminants released by human activities;

− degradation in stream morphology: bed and bank alteration, habitat degradation, riparian land use, straightening,

migration barriers, siltation;

− hydrological stress: alteration of flow regime, e.g. residual flow, pulse releases;

− general degradation: simultaneous and inseparable impacts of more than one stressor.

2.7
stressor gradient

set of sites of a fresh water ecosystem type with a varying intensity of a stressor

3 Principle

Two ways of calculating Multimetric Indices can be distinguished: the “general approach” and the “stressor-

specific approach”.

In the “general approach”, various metrics are calculated from a taxa list. The metric results are individually

compared to the respective metric values under reference conditions. From this comparison, a score for each

metric is determined. These scores are finally combined into a Multimetric Index (Figure 1).

The “stressor-specific” approach sorts a suite of metrics according to their ability to detect a certain stressor.

Thus, the scores of the metrics addressing a single stressor are first combined into a value reflecting the

intensity of this stressor. The assessment results for all stressors are finally combined into the Multimetric

Index (Figure 2).

Both ways of calculating Multimetric Indices may have advantages in certain situations: The “general

approach”, carefully applied, provides an overview of a water body’s status and is, thus, mainly suited if the

specific effects of individual stressors on the targeted organism group are not known in detail. It can, for

example, be applied for the general ecological quality assessment and for intercalibration purposes. The

“stressor specific approach” can only be applied if precise inform
...