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Integrating Geological Information in City Management to Prevent Environmental Risks. GeoInforM LIFE06 TCY/ROS/000267. SHUVALOVO area First step GWFM. Michel Fasoli Piergiorgio Valentini, Roberta Donati Province of Milan Environmental Information System Department
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Integrating Geological Information in City Management to Prevent Environmental Risks GeoInforM LIFE06 TCY/ROS/000267 SHUVALOVO area First step GWFM Michel Fasoli Piergiorgio Valentini, Roberta Donati Province of Milan Environmental Information System Department Central Directorate Environmental Resources
1. Problem Definition 2. Conceptual Model 3. MathematicalModel 4. Numerical Formulation 5. Sensitivity Analysis 6. Calibration 7. Model Application Modelling phases procedure
Aims identification for modelling • Pilot area identification • Collecting data about pilot area and regional area • Organizing data with GIS software first of all in an ArcMap project and then in a geodatabase with all original data e new data elaboration • Geological and hydrogeological data interpretation • Conceptual model definition • SOIL-GIS 2008 • Definition of Modflow and MT3D input: grid cell dimensions, boundary conditions, layers geometry, permeability, recharge, withdrawals, porosity, pollutant concentration, ecc … • Flow simulation with SOIL-GIS 2008 • Transport simulation with SOIL-GIS 2008 • Sensitivity analysis compared with K • Calibration limits compared with target wells • Application of the model in the case study after the calibration PHASE 1 PHASE 2 PHASE 3 PHASE 4 PHASE 5-6 PHASE 7 Modelling phases procedure
GG1 cross-section Conceptual model All layers are continuous in the model !!!
Elevation data from: Altitude points Boreholes (from database and from sections) Water levels Daylight relief isolines Lakes fictitious points Top inter moraine isolines Prequaternary relief isolines Tops correction fictitious points Numerical formulation Top of prequaternary is the bottom of 8 layer
Numerical formulation
The interpolation for some layers (with few elevation points) gives problems of intersections between contiguous layers (see example in the next slide) In this case is necessary to put in some fictitious points to avoid the problem Tops correction
In this example layer 8 bottom (below/green) intersects layer 8 top (above/grey) in three areas Tops correction
3D Surfer representation 9 surfaces elevation
3D Surfer representation 9 surfaces elevation
3D Surfer representation 9 surfaces elevation
Tables GEODB Database Shapefiles Raster Geological and Hydrogeological interpretation Interpolation GridConvert ESRI grid for SOIL-GIS 3D Surfer grid Modelling methodology
Constant head Lakes as constant head Rivers Lakes as constant head Rivers GW aquifer Boundary conditions (layers 1-2-3)
? Constant head Constant head IM aquifer Boundary conditions (layers 5-6-7)
Grid cells of 10-50 meters are the ideal to study Shuvalovo area and in particular the lakes, the most important elements to modelling. Discretization domain
The next steps will be the definition of: permeability grids for each layers (we will simulate a situation with minimum K values and another with maximum K values); porosity grids estimate from K values; withdrawals grids (known or estimated); recharge grids (% infiltration); wells as control target. In the next future …
K range ? ? Is correct? Permeability
? Dusty sand in Lithology.shp Fine sand in Boreholes.mdb Permeability
Various grain size sand in Lithology.shp Medium grain size sand in Boreholes.mdb ? Permeability
Piezometry Differences between GW_Water_level_max.shp in blue and Daylight_Relief.shp in black
Piezometry Differences between GW_Water_level_max.shp in blue and interpolation of GW boreholes maximum water level in red
Piezometry Differences between IM_Water_level_max.shp in blue and interpolation of IM boreholes minimum water level in red
DEM Differences between Daylight_Relief.shp in black and interpolation of altitude points in red
Static and dynamic piezometric surface (checked with target control) Water exchange estimate between GW aquifer and IM aquifer according to reciprocal K values Flow expected results
Future actions ? To respect the future actions of the Province of Milan we need to know the data necessary for a complete flow and transport simulation
THANKS for your precious attention !!!