Hydrogeological modeling of the Landenian sands Hydroland project, Aquale sprl

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1 ARTESIA ENVIRONNEMENT Hydrogéologie, Géologie, Géothermie en région bruxelloise Nouveaux outils, données et connaissances Hydrogeological modeling of the Landenian sands Hydroland project, Aquale sprl March 19 1

2 PLAN 1. Context and et objectives 2. Conceptual model and numerical model 3. Calibration 4. Sensitivity study 5. Results 6. Conclusions 7. Consultation March 19 2

3 1. CONTEXT AND OBJECTIVES March 19 3

4 1. CONTEXT AND OBJECTIVES The objectives were : reference piezometric maps for all the hydrogeological units in Brussels and free distribution via web platforms construction of an internal decision-making tool at Brussels Environment simulate groundwater flow processes estimate available resources quantify groundwater exchanges with the Flemish Region Regional scale Geological model developed by SGB March 19 4

5 1. CONTEXT AND OBJECTIVES Piezometric reference maps : - Alluvial aquifer system - Perched aquifer system - Brusselian aquifer - Tielt aquitard - Kortrijk aquitard system - Landenian aquifer => Hydroland - data - collection Phreatic heads - Phreatic depths Proactive groundwater management : - piezometric sustainability : global warming, catchments, piezometric network optimization - groundwater quality sustainability : groundwater pollution sources, quality network optimization - geothermal energy developpement management - permitting : catchments, urban developpement, geothermal energy March 19 5

6 2. CONCEPTUAL MODEL AND NUMERICAL MODEL March 19 6

7 2. CONCEPTUAL MODEL AND NUMERICAL MODEL Top : the base of the Member of Saint-Maur Bottom : the base of the Grandglise Member March 19 7

8 2. CONCEPTUAL MODEL AND NUMERICAL MODEL March 19 8

9 2. CONCEPTUAL MODEL AND NUMERICAL MODEL March 19 9

10 2. CONCEPTUAL MODEL AND NUMERICAL MODEL March 19 10

11 2. CONCEPTUAL MODEL AND NUMERICAL MODEL March 19 11

12 3. CALIBRATION March 19 12

13 3. CALIBRATION et cote du réseau hydrographique March 19 13

14 3. CALIBRATION March 19 14

15 3. CALIBRATION Adjustment of aquifer properties : Hydraulic conductivity Infiltration Porosity Storage coefficient March 19 15

16 3. CALIBRATION SRMFS : 1.3 % for the whole model SRMFS : 1.3 % for the Brussels Region March 19 16

17 3. CALIBRATION March 19 17

18 3. CALIBRATION March 19 18

19 3. CALIBRATION It is considered that the calibration level will have to be improved by the acquisition of additional data to reproduce the transient phenomena observed in the short and long term. March 19 19

20 4. SENSITIVITY STUDY March 19 20

21 4. SENSITIVITY STUDY March 19 21

22 4. SENSITIVITY STUDY Infiltration Hydraulic conductivity Pumping rate Boundary conditions Porosity Storage coefficient March 19 22

23 5. RESULTS March 19 23

24 5. RESULTS and many scenarios to meet the goals March 19 24

25 6. CONCLUSIONS March 19 25

26 6. CONCLUSIONS The groundwater of the Landenian Sands flows from South-East to North-West in the Brussels Region. The piezometry is mainly influenced by the variation of the recharge, and therefore of the rainfall, the outside temperature and urbanization (at the level of the recharge zone, therefore outside Brussels). The pumping rate also has a very important influence on the piezometry. It clearly appears from historical piezometric data but also through the results obtained using the different scenarios. The current state of resources is satisfactory and has grown significantly for many years. It will remain satisfactory if the exploitation of the aquifer remains reasonable. March 19 26

27 6. CONCLUSIONS Decision-making tool Ready-to-use Multiple uses Use this map considering that : there are many uncertainties on the source data there is a lot of missing data the water levels are calibrated with 1-2 m error the model is calibrated for regional use March 19 27

28 7. CONSULTATION March 19 28

29 7. CONSULTATION Dataset : HE/BHG 1 Quartaire aquifersysteem HE/BHG 2 Hangend zandige aquifersysteem HE/BHG 4 Zand van Wemmel, Lede, Brussel en Vlierzele aquifersysteem HE/BHG 6 Zand en klei van Tielt aquitard HE/BHG 7 Zand en klei van Kortrijk aquitardsystem HE/BHG 8 Landeniaan zand aquifer (HYDROLAND) Diepte van het freatisch vlak (m) Hoogte van het freatisch vlak (m-taw) Data diffusion : Isolines = 2 m Spatial Data Infrastructure (SDI) Web Feature Services (WFS) March 19 29

30 THANK YOU FOR YOUR ATTENTION March 19 30