Compilation and Assessment of a European-wide Groundwater Body Reference Layer Federal Institute for Geosciences and Natural Resources (BGR), Germany Klaus Duscher Working Group C Plenary Meeting 20.03.2012 (Brussels)

GWB reference layer compilation GWB quality assurance issues Topics GWB submission status GWB reference layer compilation GWB quality assurance issues GWB reference layer revision Case study: Horizon assignment Conclusions

Available GWB Data 2011 . 3

GWB Layer Compilation - Methodology 12590 polygons from RBMP data merged to one shape for each horizon 1 to 5 plus one shape of polygons without allocated horizons  6 shapes with attributes GWB key and Horizon Merge of 531 polygons of countries providing only WFD article 5 data without vertical stratification  1 shape with GWB key 29 polygons of Non MS (CH) assigned to horizon 1  1 shape with GWB key  Compilation of 8 individually portrayable layers 4

GWB Reference Layer – Survey Map Remark: Data evaluation comprises exclusively WFD article 13 data of EU member states 5

BGR is mandated to generate a GWB reference layer by ETC/ICM GWB Layer Assessment BGR is mandated to generate a GWB reference layer by ETC/ICM Report on compilation of GWB map with description of quality assurance issues in general Documents describing selected QA issues per MS including examples  No complete list Workshop Dec 2011 organised by EuroGeoSurveys/BGR  QA issues in terms of generating a GWB reference layer are no deficits concerning WFD obligations  Relevance of a coherent European-wide mapping of the WFD GW survey results 6

GWB Reference Layer – Assessment Results WFD article 13 reporting not complete Missing data of MS Lack of entries for GWB attributes (XML data) Data inconsistency Spatial data  e.g. Topological and geometric errors Attribute data  e. g. Transboundary GWBs Mismatch of spatial (polygons) and attribute (XML) data Demand of coordination between MS GWB outlines not adjusted along country borders Harmonisation of GWB delineation methodology (e. g. Horizon)  Replenishment and review of data for further GWB Layer developments is required

GWB Layer Revision Improvement of current GWB reference layer by a coordinated revising of following issues: Unique GWB code GWB size and amount GWB multipart fragmentation Generalisation of GWB outline / details ERM border topology Topology and geometry Unique GWB position Attribute data quality Interpreting Horizons

Revision – Size / Amount 46% of all polygons (5831) less than 5 km2 and 20% of all polygons (about 2500) less than 1 km2 Majority of small GWBs in FI and SE  Feasibility of monitoring a large amount of small GWBs? GWBs of small size may be aggregated / generalised

Revision – Multipart fragmentation Multipart polygon consisting of - 1175 elements - 433 elements Generalisation

Spatial Data – Border Topology  GWB polygon outline do not match ERM country border  overlaying GWBs along border 11

Revision – Spatial data quality  Cleaning of topological inconsistent spatial data

Revision – Technical Deficits  Fractional GWB  Multiple fractional GWBs  Geometrical error

Spatial Data – Uncovered Areas SE ES IT SK GWBs do not cover entire territory Small GWBs or no GW resources or reporting deficit? 14

Completeness of GWB Attribute Entries Six mandatory attributes marked as blue rows, reporting of 15 remaining characteristics related to GWBs is optional  Insufficient entries for evaluation of several attributes (< 50 % of total datasets - red coloured)

Transboundary GWBs  Inconsistent, because occurrence only on certain borders and in some cases only on one side of a border

GWB Delineation – Vertical positioning 3-dimensional delineation Position in vertical aquifer sequence Horizon Layer Assignment Thickness Depth Inclination 17

Horizon assignment – Current status  Horizon allocation changes along borders 18

Revision – GWB unique vertical position GWB FRFG080 consisting of several polygons in several horizons GWBs in horizon 1 overlying each other Assessment problems  preferable structure GWB confined to a single horizon No overlying GWBs in same horizon

GIS Guidance – Horizon concepts Horizons simply numbered from surface Multiple 4th horizon for deep GW resources Current GIS Guidance Document 22, App. 13.3, p.29 (2009)  Uppermost GWB always assigned horizon 1? Older draft version GIS Guidance Document 22, App. 13.3, p.21 Hydrogeological horizon definition Main layer is second horizon  Concept for comparable assignment in different MS?  Majority of GWB allocated in horizon 1 / 2

French GWB Horizon Concept Systematic assignment of upper GWB to horizon 1 Upper GWB changes from horizon 1 to 2 in areas with overlying GWB (see GWB B below) GWB is split in several spatial elements in case of changing horizons  Complicated GWB structure with several polygons in different horizons  Implementation of current guidance GWB FRHG 310 GWB FRFG 080

Horizon assignment in CZ / SK Overlay GWBs horizon 1 - IHME GWBs horizon 2 - IHME  Implementation of older draft guidance

Horizon assignment – Current status  Horizon allocation changes along borders

WISE – Groundwater Viewer * Outline of GWBs in a single or several horizons Qualitative and quantitative GWB status Trend und trend reversal Basic informations (GWB name, code, area,..) Display of GWBs in a scale over 1 : 2,500,000 Scales below 1 : 2,500,000 show aggregated values per RBD or MS!! * http://www.eea.europa.eu/themes/water/interactive/soe-wfd/wfd-gw/ 24

Horizon assignment – Solution proposal GWBs of DE, AT, PL in section  horizon number + 1

Summary First RBMP reporting of GWBs is not complete yet and process of GWB qualification is ongoing Spatial data of GWBs from WFD article 13 or 5 for all MS Current quality of GWB spatial data not sufficient for use as reference layer More precise guidance preferable Harmonisation between MS and revision requested QA issues may be optimised with reasonable expenditure Improvement of data quality can be expected with next RBMP  Mutual efforts required to achieve a GWB reference layer for use in GIS analysis