Water quality - Guidance standard on determining the degree of modification of lake hydromorphology

This European Standard provides guidance on determining the degree of modification of lake hydromorphological features described in EN 16039. It enables consistent comparisons of hydromorphology between lakes within a country and between different countries in Europe, providing a method for broad based characterization across a wide spectrum of hydromorphological modification. Its primary aim is to assess ‘departure from naturalness’ for a given type of lake as a result of human pressures, and it suggests suitable sources of information that may contribute to characterizing the degree of modification of hydromorphological features. For wholly artificial lakes or reservoirs formed by damming rivers the aim is to assess the extent to which processes approximate to those in comparable natural water bodies. However, this standard does not replace methods that have been developed within particular countries for local assessment and reporting. Decisions on management for individual lakes require expert local knowledge and vary according to lake type.

Wasserbeschaffenheit - Anleitung zur Bestimmung der hydromorphologischen Eigenschaften von Seen

Qualité de l'eau - Préconisations pour la détermination du degré de modification des caractéristiques hydromorphologiques des lacs

La présente Norme européenne donne des préconisations sur la détermination du degré de modification des caractéristiques hydromorphologiques des lacs décrites dans l'EN 16039. Elle permet des comparaisons uniformes de l'hydromorphologie entre différents lacs dans un pays, et entre différents pays européens, en offrant une méthode de caractérisation à large échelle à travers un vaste éventail de modifications hydromorphologiques. Elle a pour but premier d'évaluer « l'écart par rapport au caractère naturel » pour un type de lac donné par suite de pressions anthropiques, et elle suggère des sources d'informations pertinentes pouvant contribuer à caractériser le degré de modification des caractéristiques hydromorphologiques. Dans le cas de lacs entièrement artificiels ou de réservoirs créés en construisant un barrage sur un cours d'eau, le but est d'évaluer dans quelle mesure les processus se rapprochent de ceux existant dans des masses d'eau naturelles comparables. La présente norme ne remplace toutefois pas les méthodes locales d'évaluation et de rapportage qui ont été élaborées dans certains pays. Les décisions concernant la gestion de lacs individuels exigent une expertise locale, et varient suivant le type de lac. L'évaluation des conditions hydromorphologiques pour les besoins de la DCE (qui soutiennent les éléments de qualité biologique) reste de la compétence des différents États membres.

Kakovost vode - Navodilo za določevanje stopnje spremenjenosti hidromorfoloških značilnosti jezer

Ta evropski standard podaja navodilo za določevanje stopnje spremenjenosti hidromorfoloških značilnosti jezer, opisanih v standardu EN 16039. Omogoča usklajene primerjave hidromorfologije med jezeri v državi in med različnimi evropskimi državami, za kar zagotavlja metodo za vsesplošno karakterizacijo širokega spektra hidromorfoloških sprememb. Njegov osnovni namen je ocena »odmika od naravnosti« za dano vrsto jezera kot posledica pritiskov s strani človeka in predlaga ustrezne vire informacij, ki lahko prispevajo k karakterizaciji stopnje spremenjenosti hidromorfoloških značilnosti. Pri povsem umetnih jezerih ali vodnih zbiralnikih, nastalih z zajezitvijo rek, je cilj oceniti obseg, v katerem se procesi približajo procesom v primerljivih naravnih vodnih telesih. Vendar pa ta standard ne nadomešča metod, razvitih v posameznih državah za namene lokalne ocene in poročanja. Za odločitve glede upravljanja za posamezna jezera je potrebno lokalno strokovno znanje, ki se razlikuje glede na vrsto jezera.

General Information

Status
Published
Public Enquiry End Date
09-Aug-2015
Publication Date
16-May-2017
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
12-May-2017
Due Date
17-Jul-2017
Completion Date
17-May-2017

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wasserbeschaffenheit - Anleitung zur Bestimmung der hydromorphologischen Eigenschaften von SeenQualité de l'eau - Préconisations pour la détermination du degré de modification des caractéristiques hydromorphologiques des lacsWater quality - Guidance standard on determining the degree of modification of lake hydromorphology13.060.10Voda iz naravnih virovWater of natural resources07.060Geologija. Meteorologija. HidrologijaGeology. Meteorology. HydrologyICS:Ta slovenski standard je istoveten z:EN 16870:2017SIST EN 16870:2017en,fr,de01-junij-2017SIST EN 16870:2017SLOVENSKI

STANDARD
SIST EN 16870:2017
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16870
February
t r s y ICS
r yä r x râ
s uä r x rä v w English Version

Water quality æ Guidance standard on determining the degree of modification of lake hydromorphology Qualité de l 5eau æ Guide pour la détermination des conditions hydromorphologiques des lacs

Wasserbeschaffenheit æ Anleitung zur Bestimmung der hydromorphologischen Eigenschaften von Seen This European Standard was approved by CEN on

v December
t r s xä

egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä

translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä

CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä

EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels

t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN

s x z y rã t r s y ESIST EN 16870:2017

EN 16870:2017 (E) 2 Contents Page European foreword ....................................................................................................................................................... 4 Introduction .................................................................................................................................................................... 5 1 Scope .................................................................................................................................................................... 6 2 Normative references .................................................................................................................................... 6 3 Terms and definitions ................................................................................................................................... 6 4 Principle .......................................................................................................................................................... 10 5 Determining the hydromorphological modifications of lakes .................................................... 10 5.1 Feature categories ....................................................................................................................................... 10 Table 1 — Features to be assessed when determining the hydromorphological modifications of lakes ................................................................................................................................. 11 5.2 Procedure for scoring ................................................................................................................................. 11 Table 2 — Conversion table .................................................................................................................................... 12 6 Interpreting and reporting hydromorphological modifications ................................................ 12 6.1 Modification scores ..................................................................................................................................... 12 Table 3 — Options, applications and procedures for reporting hydromorphological modification scores ..................................................................................................................................... 13 6.2 Assigning classification terms ................................................................................................................. 13 Table 4 —

Classification terms for 5 classes (Score band A) ..................................................................... 14 Table 5 — Classification terms for 3 classes (Score band B) ...................................................................... 14 Annex A (normative)

Characterization of lake modification based on hydromorphological features ............................................................................................................................................................ 15 Table A.1 — Characterization of lake modification based on hydromorphological features ........ 16 Annex B (normative)

Alterations to mean annual water level range..................................................... 29 Table B.1 — Alterations to mean annual water level range ....................................................................... 29 Annex C (normative)

Land cover in the lake catchment ............................................................................. 31 Table C.1 — Land cover in the lake catchment ................................................................................................ 31 Annex D (informative)

Case study examples ................................................................................................... 32 D.1 Lago Maggiore (Italy) .................................................................................................................................. 32 D.1.1 Summary description ................................................................................................................................. 32 Figure D.1 — Location of Lago Maggiore ............................................................................................................ 32 D.1.2 Morphometric characteristics ................................................................................................................. 33 Table D.1 — Morphometric characteristics of Lago Maggiore ................................................................... 33 D.1.3 Degree of modification using Annex A.................................................................................................. 33 Table D.2 — Modification scores for Lago Maggiore, using reporting option 1 .................................. 33 Table D.3 — Modification scores for Lago Maggiore using reporting options 2, 3 and 4 ................. 34 SIST EN 16870:2017

EN 16870:2017 (E) 3 D.1.4 Conclusions ..................................................................................................................................................... 34 D.2 Lago Bidighinzu (Italy) ............................................................................................................................... 35 D.2.1 Summary description .................................................................................................................................. 35 Figure D.2 — Location of Lago Bidighinzu ......................................................................................................... 35 D.2.2 Morphometric characteristics ................................................................................................................. 36 Table D.4 — Morphometric characteristics of Lago Bidighinzu ................................................................ 36 D.2.3 Degree of modification using Annex A .................................................................................................. 36 Table D.5 — Modification scores for Lago Bidighinzu, using reporting option 1 ................................ 36 Table D.6 — Modification scores for Lago Bidighinzu using reporting options 2, 3 and 4 .............. 37 D.2.4 Conclusions ..................................................................................................................................................... 37 D.3 Lake Lidzbarskie (Poland) ........................................................................................................................ 38 D.3.1 Summary description .................................................................................................................................. 38 Figure D.3 — Location of Lake Lidzbarskie and a map of its bathymetry .............................................. 38 D.3.2 Morphometric characteristics ................................................................................................................. 38 Table D.7 — Morphometric characteristics of Lake Lidzbarskie .............................................................. 39 D.3.3 Degree of modification using Annex A .................................................................................................. 39 Table D.8 — Modification scores for Lake Lidzbarskie, using reporting option 1 .............................. 39 Table D.9 — Modification scores for Lake Lidzbarskie using reporting options 2, 3 and 4 ............ 41 D.3.4 Conclusions ..................................................................................................................................................... 41 D.4 Lake Velenje (Slovenia) .............................................................................................................................. 41 D.4.1 Summary description .................................................................................................................................. 41 Figure D.4 — Location of Lake Velenje ................................................................................................................ 42 D.4.2 Morphometric characteristics ................................................................................................................. 42 Table D.10 — Morphometric characteristics of Lake Velenje .................................................................... 42 D.4.3 Degree of modification using Annex A .................................................................................................. 43 Table D.11 — Modification scores for Lake Velenje, using reporting option 1 .................................... 43 Table D.12 — Modification scores for Lake Velenje using reporting options 2, 3 and 4 .................. 44 D.4.4 Conclusions ..................................................................................................................................................... 44 D.5 Arkanj Lake (Serbia) ................................................................................................................................... 44 D.5.1 Summary description .................................................................................................................................. 44 D.5.2 Morphometric characteristics ................................................................................................................. 44 Table D.13 — Morphometric characteristics of Arkanj Lake ...................................................................... 45 D.5.3 Degree of modification using Annex A .................................................................................................. 45 Table D.14 — Modification scores for Arkanj Lake, using reporting option 1 ..................................... 46 Table D.15 — Modification scores for Arkanj Lake, using reporting options 2, 3 and 4 ................... 47 D.5.4 Conclusions ..................................................................................................................................................... 47 SIST EN 16870:2017

EN 16870:2017 (E) 4 European foreword This document (EN 16870:2017) has been prepared by Technical Committee CEN/TC 230 “Water analysis”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2017, and conflicting national standards shall be withdrawn at the latest by August 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 16870:2017

EN 16870:2017 (E) 5 Introduction This European Standard will enable broad comparisons to be made of the hydromorphological condition of lakes throughout Europe (e.g. for reporting by the European Environment Agency). In this document, the word ‘lake’ is used as a generic term for standing waters including natural lakes, reservoirs, excavated pits and other artificial water bodies. The Guidance standard for assessing the hydromorphological features of lakes (EN 16039) describes a protocol for survey (field and remote sensing methods) and feature recording, whereas this standard gives guidance on assessing the condition of those features, and focuses especially on human pressures that affect lakes. This standard has applications for nature conservation, environmental impact assessment, lake management, and guiding lake restoration work. The assessment of lake ‘quality’ in Europe has evolved over the past decades from its focus on chemical conditions to a more comprehensive ecological approach. The EC Water Framework Directive (WFD) has reinforced the need for this broader view of lake ‘quality’ through its requirement for determining ‘ecological status’ based on phytoplankton, phytobenthos, macrophytes, invertebrates and fish. The Directive also requires hydromorphological and physico-chemical conditions to be suitable for supporting biological communities. This standard, therefore, may be helpful for implementing the WFD when indicating the extent to which pressures might have caused a departure from natural hydromorphological conditions. In doing so it complements methods that have been developed within particular countries for assessment and reporting under the WFD. However, this standard makes no links between hydromorphology and biology, nor does it set any hydromorphological condition targets that should be achieved. Whereas decisions on management for individual lakes require expert local knowledge and vary according to lake type, this standard provides a framework to help those decisions to be made consistently. SIST EN 16870:2017

EN 16870:2017 (E) 6 1 Scope This European Standard provides guidance on determining the degree of modification of lake hydromorphological features described in EN 16039. It enables consistent comparisons of hydromorphology between lakes within a country and between different countries in Europe, providing a method for broad based characterization across a wide spectrum of hydromorphological modification. Its primary aim is to assess ‘departure from naturalness’ for a given type of lake as a result of human pressures, and it suggests suitable sources of information that may contribute to characterizing the degree of modification of hydromorphological features. For wholly artificial lakes or reservoirs formed by damming rivers the aim is to assess the extent to which processes approximate to those in comparable natural water bodies. However, this standard does not replace methods that have been developed within particular countries for local assessment and reporting. Decisions on management for individual lakes require expert local knowledge and vary according to lake type. The assessment of the hydromorphological conditions as needed for the WFD (supporting the biological quality elements) remains in the competence of the individual Member States. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 15843:2010, Water quality - Guidance standard on determining the degree of modification of river hydromorphology EN 16039:2011, Water quality - Guidance standard on assessing the hydromorphological features of lakes 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 bank physical edge of the lake shore, or of the island(s) within, generally defined by a wave-cut break in slope at or near the water’s edge of the lake, but can also be defined as the line along which riparian (terrestrial or land) conditions change to littoral in-lake conditions [SOURCE: EN 16039:2011, definition 3.3] 3.2 bar discrete, natural, depositional feature with shallow slope into water composed of unconsolidated material 3.3 bathymetry systematic survey of size, shape and water depth distribution in a lake Note 1 to entry: Bathymetry is the basis of deriving morphometric parameters and to predict thermal stratification, residence time and sediment redistribution processes. [SOURCE: EN 16039:2011, definition 3.5] SIST EN 16870:2017

EN 16870:2017 (E) 7 3.4 catchment drainage basin contributing water and sediment into a lake (also recognized as drainage area) [SOURCE: EN 16039:2011, definition 3.10] 3.5 connectivity continuity uninterrupted movement of water, sediment and organisms into, out of and within a lake system [SOURCE: EN 16039:2011, definition 3.11] 3.6 drawdown lowering of lake levels caused by deliberate water release 3.7 dune underwater ridge formed by wave or current action on the lake bed 3.8 ecological status expression of the quality of the structure and functioning of aquatic ecosystems, by comparing the prevailing conditions with reference conditions Note 1 to entry: As classified in accordance with Annex V of the EC Water Framework Directive. 3.9 embeddedness extent to which fine sediment infiltrates littoral gravels 3.10 gauging board staff gauge graduated scale, fixed to a lake outlet or inflow structure, or directly into the substrate, used to measure the water level in a lake 3.11 geotextile permeable fabric often used to reinforce or protect banks 3.12 groundwater table surface of a body of underground water below which the soil or rocks are permanently saturated with water 3.13 hard engineering stabilization of the shoreline using ‘hard’ materials including concrete walls, gabion baskets and sheet piling SIST EN 16870:2017

EN 16870:2017 (E) 8 3.14 hydromorphology physical and hydrological characteristics of lakes including the underlying physical processes from which they result [SOURCE: EN 16039:2011, definition 3.22] 3.15 island landform protruding from the surface of a lake [SOURCE: EN 16039:2011, definition 3.26] 3.16 lake stratification variations in water column structure with respect to temperature and density [SOURCE: EN 16039:2011, definition 3.30] 3.17 littoral zone habitat extending from the water’s edge to the lakeward limit of rooted macrophytes or algae on the lake bed [SOURCE: EN 16039:2011, definition 3.33] 3.18 pelagic zone open water zone extending from the littoral zone towards the centre of a lake [SOURCE: EN 16039:2011, definition 3.41] 3.19 planform view of lake shape from above, e.g. elongate, circular, etc., and also relevant in relation to the shoreline development index which expresses the degree of irregularity of a lake compared with a circular form of the same area [SOURCE: EN 16039:2011, definition 3.42] 3.20 profundal zone deeper parts of the lake where light does not penetrate and there is no photosynthetic activity 3.21 ramping rate rate of rise and fall of water levels often associated with hydropower generation 3.22 remote sensing group of techniques for acquiring data on land forms and land cover (e.g. aerial photographs, satellite imagery, radar, sonar) SIST EN 16870:2017

EN 16870:2017 (E) 9 3.23 residence time retention time time for water in a lake to be replaced, which can be calculated in a range of ways (e.g. instantaneous, seasonal, annual) and may be applied to the entire lake, to individual lake basins or to strata within the lake 3.24 riparian zone area of land adjoining the lake capable of directly influencing the condition of the aquatic ecosystem (e.g. by shading and leaf litter input) [SOURCE: EN 16039:2011, definition 3.45] 3.25 scour hole depression in the lake bed created by wave or current action 3.26 shore zone comprises riparian, eulittoral and littoral zones around the perimeter of a lake [SOURCE: EN 16039:2011, definition 3.48] 3.27 sidescan sonar sonar scanning obliquely onto the lake bed used to characterize lake-bottom features 3.28 soft engineering stabilization of the shoreline using ‘soft’ materials including basket-work, planted saplings and live willow, dumped natural debris (to re-nourish sediment supply) and degradable synthetic materials Note 1 to entry: Also includes earth-moving where re-sectioning and re-profiling takes place 3.29 step feature of erosion where a lake bank or an old depositional bar has been eroded to create distinct edges (steps) into water Note 1 to entry: Several steps can develop down the shore to reflect different periods of erosion at times of different water level 3.30 substrate (substratum) natural sediment or engineered surfaces comprising the shore and bed of a lake Note 1 to entry: Natural sediments are generally characterized by texture and organic matter content, while artificial substrates are described by their construction materials [SOURCE: EN 16039:2011, definition 3.49] SIST EN 16870:2017

EN 16870:2017 (E) 10 3.31 tracer experiment one of a group of hydrogeological field techniques used to quantify groundwater flow 3.32 water balance flow of water into and out of a lake (e.g. groundwater, rain water, evaporation) 3.33 wetland transitional zone between permanently inundated, and generally dry, environments, e.g. marshes (wet ground without peat), fens (groundwater fed peats) and bogs (rain-fed peat systems) [SOURCE: EN 16039:2011, definition 3.52] 3.34 willow spiling method of soft engineering used to strengthen lake shores using retaining walls constructed of woven willow stems from which trees will sprout 4 Principle A standard protocol is described for assessing the degree of modification of the hydromorphological features of different lake zones. Both this European Standard and EN 16039 focus attention on lake features as surrogates for lake processes. Those making assessments, therefore, do not need to be trained geomorphologists although some geomorphological input may be useful. To ensure consistency in approach, the main feature categories are in general the same as those in EN 16039. However, some minor adjustments have been made to the details to help facilitate scoring. 5 Determining the hydromorphological modifications of lakes 5.1 Feature categories Assessments are made for the feature categories listed in EN 16039, with subdivisions into specific features where appropriate (Table 1). SIST EN 16870:2017

EN 16870:2017 (E) 11 Table 1 — Features to be assessed when determining the hydromorphological modifications of lakes Feature category Feature 1. Hydraulics Water level variability Lake volume 2. Morphometry Slope profile of shore zone Planform Depth distribution 3. Bedforms/Landforms and Substrate Landform and substrate characteristics Bank structure and modifications Littoral substrate Lake bottom bedforms Extent of artificial material/imported natural substrate 4. Connectivity and Continuity Natural exchange with groundwater Connectivity of lake with adjacent riparian wetlands Natural erosion/deposition patterns Natural exchange between groundwater and surface water Migratory movement Sediment transport 5. Aquatic Vegetation Human disturbance or active management of aquatic vegetation (shore zone) Human disturbance or active management of aquatic vegetation (open water zone) 6. Land Cover Land cover in riparian zone 5.2 Procedure for scoring 5.2.1 Users should note whether the lake being assessed is natural (N), heavily modified (H) or artificial (Ar). Annex A sets out guidance on how to allocate scores for each feature category. It contains two separate procedures for scoring – using score band A with quantitative data, or score band B with qualitative data. Score band A is a 5-point scale (1 = lowest degree of modification, 5 = highest degree of modification). Score band B is a 3-point scale (1, 3, 5; following the same general approach as for score band A). Quantitative data should always be used where available; where there are quantitative data for some of the features but not for all, a mix of quantitative and qualitative data may be used. Users should state which scores have been assigned based on quantitative data and which on qualitative descriptions, as this determines the degree of confidence in the assessment. This note should also be added to any maps produced that show the results of lake hydromorphological assessment. 5.2.2 Where the majority of scores have been derived from 5-band scales users may wish to retain the five bands. Where the majority have been derived from 3-band scales users may wish to change the 5-band scores to 3-band scores as follows, making clear in the results which scores have been changed in the way given in Table 2. SIST EN 16870:2017

EN 16870:2017 (E) 12 Table 2 — Conversion table 5-band score 3-band score 1 1 2 1 3 3 4 5 5 5 5.2.3 For those features where scoring 1 = 0 % to 5 % change, an asterisk should be added (i.e. 1*) where the recorded change is only 0 % to 1 %. This is to highlight lakes with extremely low levels of modification. A ''symbol should be added (i.e. 5) to indicate extreme levels of modification. 5.2.4 The importance of each of the features in Annex A for hydromorphological and ecological functioning will not be the same. However, at present there is insufficient scientific evidence to justify differential weighting of the scores allocated. 5.2.5 Three additional annexes are included in this standard. Annex B provides information to support interpretation of the scoring system for the ‘water level variability’ feature. Land cover in the wider catchment (Annex C) is included so that this information can be collated in order to provide context for the scored assessment of a lake. (This is undertaken as a separate assessment and does not form part of the hydromorphological assessment of the lake itself.) Annex D provides case studies to help in understanding and interpreting the overall scoring system. These examples include a description of the lake, a map, a summary of the scores with some interpretation, and a short conclusion. 6 Interpreting and reporting hydromorphological modifications 6.1 Modification scores Scores should be reported as shown in Table 3. This process provides a range of options for different purposes, but shows clearly how each of the three combined scores (options 2, 3 and 4 in Table 3) has been derived. SIST EN 16870:2017

EN 16870:2017 (E) 13 Table 3 — Options, applications and procedures for reporting hydromorphological modification scores Reporting option Examples of applications Procedure 1: Tabulate 16 scores separately Providing maximum amount of information for lake management. Score as in Annex A for all features; do not combine. 2: Create a 2-digit code Reporting lake modification within the two main hydromorphological quality elements given in the WFD (hydrological regime, morphological conditions) but with no attempt to link hydromorphology with biology. Combine the scores for category 1 to create a single mean score for hydrological regime (the first of the two digits). Scores should be rounded up or down to the nearest integer (rounding up any that end in 0,5). Combine the scores for categories 2–6 to create a single mean score for morphological conditions (the second of the two digits). Scores should be rounded up or down to the nearest integer (rounding up any that end in 0,5). [For example, a code of 1,1 would indicate a lake with near-natural hydrology and with the lowest degree of morphological modification.] 3: Group features according to zone Reporting on the three main lake zones: open water pelagic/ profundal zone, shore zone, and riparian zone, as recommended in EN 16039. Feature categories should be grouped and mean scores calculated for the three zones. Scores should be rounded up or down to the nearest integer (rounding up any that end in 0,5).

4: Produce a single score for the lake assessed Reporting overall hydromorphological modification of a lake witho

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