Compilation of Groundwater Body GIS Reference Layer

1. Compilation ofGroundwater Body GIS Reference Layer Klaus Duscher ETC/ICM - Federal Institute for Geosciences and Natural Resources (BGR), Germany Event/ date: WG D meeting, 7 April 2011, Brussels Author: Klaus Duscher, ETC/ICM-BGR

2. Topics • GWB definition / delineation • GWB data submission 2010 • GWB layer compilation • Spatial data evaluation • XML attribute data evaluation • Conclusions and outlook Event/ date: WG D meeting, 7 April 2011, Brussels Author: Klaus Duscher, ETC/ICM-BGR

3. GWB – Delineation WFD (Art. 2) - A distinct volume of groundwater within an aquifer or aquifers (Remark: Aquifer – geological strata with significant groundwater flow) GWBs (yellow) overlaying IHME (hydrogeological structures) Comparison of two German sections GWBs partially match hydrogeological structures  Hydrogeological criteria • GWBs do not match • hydrogeological structures • Management criteria

4. GWB Submission 2010 – Specification • New requests with submission 2010 • Space-oriented and 3-dimensional formation of GWBs • Overlying GWB assigned to different vertical horizons • Attributes of GWB dimension and properties requested   • Spatial data as polygon shapes • - GWB Code (EU_CD_GW) • - Horizon • Attribute data as XML schema (database import) • - GWB Code (EU_CD_GW) • - Further GWB characteristics

5. Submitted GWB Data 2010 and Supplements • Delivery by all MS except CY, DK, EE, HU, LU, MT, SI and PT • Nov 2010: Finalised submission by 9 MS and Draft status by 10 MS • Missing XML data from IT and LV • Additional Data of 2008 Submission available for CY, DK, EE, HU, LU and PT  No Data for MT and SI  Vertical stratification of GWBs implemented by 12 MS(AT, BE, BG, CZ, DE, ES, FR, NL, IT, RO, SE, SK)

6. GWB Submission 2010 - Horizon

7. GWB Layer Compilation - Methodology • Polygons of Submission 2010 merged to one shape for each horizon 1 to 5 plusone shape of polygons without allocated horizons  6 shapes with attributes GWB key and Horizon • Merge of polygons of 6 additional countries with submission 2008 data without vertical stratification  1 shape with GWB key • Data of Non-MS (CH) all assigned to horizon 1  1 shape  Compilation of 8 polygon shapes

8. GWB Reference Layer – Survey Map

9. Spatial Data (2010) - Number and Size • Widely varying number of GWBs/ polygons in the MS (16 to 3616) • Many MS report either large and very small GWBs/polygons • 47% of all polygons (total number about 5400) less than 5 km2 • 20% of all polygons (total number about 2500) less than 1 km2 •  Feasibility of monitoring a large amount of small GWB areas • (258 GWBs consist of 2 to 117 polygons (748 polygons) • 40 GWBs consist of 2 to 117 polygons (226 polygons) in same horizon)

10. Spatial Data (2010) – Horizon  Horizon assignment depend on editors

11. Spatial Data (2010) – Segmented GWB • Single GWBs with several spatially separated areas saved as multipart polygons having small subareas

12. Spatial Data (2010) – Polygon/ERM Mismatch  Mismatch of ERM-borders/coastlines and GWB polygon outlines

13. Spatial Data (2010) – Topological Errors  Topological error  Fractional GWB  Multiple fractional GWBs  Geometrical error Polygon quality is not appropriate for use as reference layer

14. Alignment XML – Spatial Data • Draft version of database effective Dec. 2010(ATKINS / BGR check) • Mismatch of spatial and XML data for many MSgreen - matchblue - mostly matchred – often mismatch  Provisional data evaluation

15. Completeness of GWB attribute entries  Insufficient entries for evaluation of several attributes (< 50 % of total datasets - red colored)

16. Attribute Data Evaluation • GWB code, chemical/quantitative status and trend fully displayed in WISE • About 900 values in column area deviate > 5% from BGR calculation • Predominant geological formation are porous aquifers with moderate productivity. Fissured aquifers are of minor relevance • Boolean (Yes/no) columns (e. g. Transboundary GWB) seem to be partially filled by default values

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

18. GWBs with Association to Protected Areas  Inconsistent, because some MS report all GWB and some MS none or a marginal number of GWB (default values?)

19. Layered GWBs  GWBs reported as Layered mismatch pattern of overlying GWBs (default values?)

20. 2010 GWB Reference Layer – Conclusions • Submission 2010 not complete • Missing or not complete data of MS • Lack of entries for XML attributes • Mismatch of spatial (polygons) and attribute (XML) data  Need for replenishment and review of data • Topological and geometrical inconsistencies Spatial data not suitable for reference layer • Inconsistent attribute values (e. g. Horizon) Need for revision of attributes by MS  Replenishment and review of data for further GWB Reference Layer developments are required

21. 2010 GWB Reference Layer – Outlook • Dissemination of Report on draft GWB reference layer • Discussion of actual status with MS and/or in proper panels (e. g. WG D, WG C), need for more guidance? • Specification of data problems on MS level (support by Klaus.Duscher@bgr.de, if required) • Request for review and resubmission of GWB data by MS • Compilation of updated draft layer (15.04./15.10.) by ETC/ICM • Evaluation of draft layer quality and generation of report update • Extract of dataset on transboundary groundwaterbodies for UNECE Event/ date: WG D meeting, 7 April 2011, Brussels Author: Klaus Duscher, ETC/ICM-BGR