1. 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
(Brussels)

2. 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

3. Available GWB Data 2011 . 3

4. 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

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

6. 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

7. 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

8. 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

9. 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

10. Revision – Multipart fragmentation
Multipart polygon consisting of elements elements
Generalisation

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

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

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

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

15. 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)

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

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

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

19. 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

20. 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

21. 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

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 Implementation of older draft guidance

23. Horizon assignment – Current status
 Horizon allocation changes along borders

24. 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!! * 24

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

26. 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