Mathematical model of Baltic artesian basin version V0€¦ · 20 calculations. Verification of the...
Transcript of Mathematical model of Baltic artesian basin version V0€¦ · 20 calculations. Verification of the...
Mathematical model of Baltic artesian basin – version V0
Juris Seņņikovs Laboratory for Mathematical Modelling
of Environmental and Technological
Processes UNIVERSITY OF LATVIA
Introduction
Structure of
presentation
1.Conception of model
system
2.Geometry model
3.Conception of the
modeling task
4.Results
5.Future perspective
Introduction – groundwater modeling
Model –”An object, which is designed to replace the object under consideration,
and which resembles the studied object.“
One of the project objectives is to create mathematical model of the Baltic
artesian basin (BAB).
Model should be able to show:
1.BAB geological structure
2.BAB groundwater flow (groundwater filtration model)
3.BAB flow and transformations of solubles in the groundwater
(groundwater chemistry model)
Model will be created as a computer model. Parrarel to model development
software for data processing and vizualization of the modeling results is
created (HiFiGeo).
All of the objects needed for model operation (data, software, equations,...)
will be denoted as model system.
Information base Geometry model Hydrogeological
model
Closed 3D spatial model, which includes geological structure and properties of geological materials
Geological data monitoring data
•Objects(layers, faults, materials) • Automatic mesh generation • Stratigraphy (hronological generation)
• input • update • storage • access • remote access(web)
• 3D mesh • equations • numerical method • boundary conditions • solutions
• Result: groundwater flow in BAB •Used in activities 4a, 4b, 4c
Scheme of intergrated model system development
Development of 3D geological structure geometry
model
Geometrical model is created in layers.
Creation of each layer geometry involves several data sources, depending
on data availability, usebility....
Borehole data
Other model
data
3D
geological
structure
Layer surface and
thickness data Maps of layer
distribution
(geological maps)
Geological know-how
in areas with no data
Input data – borehole database
D3 gj-am surface
distribution borehole
data
Cm surface distribution
borehole data
Deeper you go, less
data you get...
Input data – structural surface isoline maps
Isolines and
traces of
faults on the
basement
surface
Input data– structural surface isoline maps
Basement surface
data:
In Latvia– isolines
and borhole data
In Lithuania– isolines
In Estonia– Data from
Estonian
hydrogeological
model
Rest of the model
territory–published
data
During the constraction of the model
problems of stitching the heterogenous
data was solved
Input data –geological maps
Input data – other information
Building of geometry structure algoritms
All of the layers are built on the triangular mesh. Each mesh vertex holds
layer surface height value. Triangular mesh plot permits to introduce
variable resolution level within the different meshplot areas.
Triangular meshplot for whole of the BAB area is constructed considering
common lines, such as: coastline, river/lake lines, border of geological
material distribution, traces of the tectonic faults etc.
Each surface is assigned to particular meshplot subarea within the general
meshplot.
Combining all of the surfaces we get 3D volume mesh, which is constructed
of prizm, pyramidal and tetrahetral elements.
Building of geometry structure algoritms
Typical lines Model border
Border of the
geological material
Border of Estonian
hydrogeological
model
Rivers
Building of geometry structure algoritms
Border of the triangular meshplot
coinsides with the line data
Model border
Border of the
geological material
Typical lines
Border of Estonian
hydrogeological
model
Rivers
Geometric structure - mesh
Finite element mesh,
view from the top.
Higher resolution of
mesh in areas with
sufficient geological data
Model construction algoritms
3D geological structure of the model is composed of different data sources. To
implement all of the available data into geometrical model a set of operations is
developed, known as assamblege of algoritms. Algoritms which define individual
geological surfaces are subdivided into individual blocks.
Applied algorithms are implemented using specially developed script language. This
approach has several advantages:
1. Flexibility in choosing ways to build the structure
2. Parallelization in developing/updating of different structure elements
3. Documented and repeatable structure building path
4. Possibility to rebuild the structure with slight or significant modifications at any
time
5. Possibility to build, and maintain several structures of different complexity
simultaneously
In constructing the version 0 model system, main attention was paid to the
design of the model script and its components. Model script allows to run
model construction, calculation and processing results automatically.
Algoritms for model geometry
•Surface data from borehole database
•Surface data from the structural map isolines
•Layer thickness map
To create above listed algoritms all of steps listed below need to be taken:
•Transformation of the data format
•Interpolation
•Extrapolation
•Smoothing
•Triangulation of the point assamblege
Parameters Borderline Isolines Fault lines
Database of boreholes
Filtering (MySQL)
Set of points
3D surface 2D triangulation
2D triangular mesh
3D surface Outer border
Set of 3D surfaces
Geological stratification
Volume mesh
Line
HiFiGeo volume mesh
“Law”
Table
Subquaternary rock data
Set of thicknesses
Layer thickness
DATA/Result
Algorithm
External sources (models)
Model construction algoritms
Skripta moduļa piemērs
SelectMeshRegion( MeshIn=BABRezgisBezLuzFile, EdgeIDMap=EdgDBFile, LineID=1000, ZFileOut=UpesMask.Z, SelectionSide=0 )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=SRTMtiffFile, ZFileMask=UpesMask.Z, Op=min, Dist=500, ZvalOut=Upes1.z )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=LVDEMtiffFile, ZFileMask=UpesMask.Z, Op=min, Dist=500, ZvalOut=Upes2.z )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=IOWtiffFile, ZFileMask=UpesMask.Z, Op=min, Dist=500, ZvalOut=Upes3.z )
MergeZFiles( FileIn1=Upes1.z, FileIn2=Upes2.z, FileOut=Upes.Topo.z )
MergeZFiles( FileIn1=Upes.Topo.z, FileIn2=Upes3.z, FileOut=Upes.Topo.z )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=SRTMtiffFile, ZvalOut=topoSRTM.z )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=LVDEMtiffFile, ZvalOut=topo25m.z )
InterpolateFromRaster( MeshIn=PamataRezgisFile, RasterIn=IOWtiffFile, ZvalOut=topoiow.z )
MergeZFiles( FileIn1=topoSRTM.z, FileIn2=topo25m.z, FileOut=topo.z )
MergeZFiles( FileIn1=topo.z, FileIn2=topoiow.z, FileOut=BAB.topo.z )
MergeZFiles( FileIn1=BAB.topo.z, FileIn2=Upes.Topo.z, FileOut=BAB.topo.z )
Surface topography generation
Script bloc – secīgs komandu saraksts
Command – data processing tool
Geometric structure
D2 ar-br
distribution area
Cross section A-B
Geometric structure
Cross section A-B
Geometric structure
3D attēli
HiFiGeo software
Software for visualisation of input data and results:
•Visualization of surfaces
•Visualization of vertical sections along any direction
•Visualization of horizontal sections along any level
•3D sections of any configuration
•Visualization pf piezometric head and flow velocity fields (scalar and vector
magnitudes)
•Borehole database (SQL) query definition and query results visualization
•Visualization of borehole stratification and lithology in vertical cross
sections
•Visualization of GIS layer (WMS , SHP format)
•Calculations settings management
HiFiGeo software
Borehole vizualization in cross sections
HiFiGeo software
Western Latvia geological structure, including tectonic faults, in 3D.
HiFiGeo software
SO4 concentration levels in D3 gj-am layer.
Groundwater flow calculation settings
In V0 stationary (e.g. stable and constant on a longer time frame flow )flow is calculated
Boundary conditions:
1.As model covers all of the BAB area, no flow conditions are defined for
the margins
2.Infiltration conditions are set on the surface (infiltration v0 is set constant for the whole
model area)
3.Mean discharge values are set for the water wells (in places where data is
available)
Material properties:
1.Constant horisontal and vertical permeability values for each layer,
determined during the calibration.
2.Quaternary– areally variable permeability settings. For Latvia territory
permeability is calculated using specially designed algoritm.
Calculation results are: piezometric head in each mesh point in each layer
and un flow velocity fields, as a derivative from the piezometric head field.
Material properties
Vertical permeability
(m/diurnal)
distribution of the
Quaternary.
Designed algoritms
for determining
material properties
from the borehole
lithology data
In the area outside
Latvia mean
permeability
parameters are set
Material properties
Permeability koefficent
(m/diurnal) distribution in cross
section A-B
Aquicludes – blue color layers
Aquitards – reddish layers
Boundary conditions – Surface basins
Color field represents
surface topography
Blue lines and fields
denote river betwork
and lakes.
Boundary conditions - Discharge
Water discharge points,
color denotes amount of
the discharge m3/diurnal
Latvia – Latvian
Environment, Geology
and Meteorology Centre
data
Lithuania – Geological
survey of Lithuania data
Estonia – Estonian
hydrogeological model (modified)
Calculating groundwater flow
For automation and repeatibility, similar to geology structure building,
material properties and boundary conditions are defined through script
commands.
Performance of the script can be controlled and edited on-line through a
web browser.
Groundwater flow is calculated on computing cluster. V0 is calculated on 8
core, 16 GB RAM computer.
Visualization and analysis of the calculation results is done in HiFiGeo
software.
During the calibration layer permeability properties were varied resulting in
20 calculations.
Verification of the calculated piezometric head distribution with observed
mean piesometric head in Latvia has been done.
Verification of the piezometric head – D3 fm
For comparision static
water levels obtained
during the borehole
instalation were used
350000 400000 450000 500000 550000 600000 650000 700000
6180000
6200000
6220000
6240000
6260000
6280000
6300000
6320000
6340000
6360000
6380000
-50
-30
-10
10
30
50
70
90
110
130
150
170
Verification of the piezometric head– D3 gj-am
For comparision static
water levels obtained
during the borehole
instalation were used
Vertical cross section Viļņa - Rīga – Kohtla-Järve, geological stucture
Results
Vilnius Kohtla-Järve Rīga
Results
Distribution of the piezometric head in cross section, arrows indicate
groundwater flow direction
Vertical cross section Rucava – Rīga - Pleskava, geological structure
Results
Rucava Pleskava Rīga
Results
Distribution of the piezometric head in cross section, arrows indicate
groundwater flow direction
Piezometric head in
D2 ar-br layer Results
Piezometric head in
D3 gj-am slānī
Results
Horizontal cross section, -100
m level – materials and
groundwater flow directions
Results
Horizontal cross section, -
100 m level– Materials and
isolines of piezometric head
Results
Summary
Model system: A script language is developed for automatization of geometry structure
builing and input data processing.
Geometry model: Geometry model of the BAB geological structure is developed, consisting of
24 layers
Groundwater flow model: Defined boundary conditions.
Several groundwater flow calculations.
Preliminary calibration and verification with observed data.
Software: Updated HiFiGeo software structure for geological structure and calculation
results visualization and postprocessing
Future developments
Model system: Futher development of script, generalization, simplification, documentqaion
and project staff training
Futher development of surface generation algoritms.
Geometry model: Futher integration of Lithuania geology data (faults, water discharge,
material properties).
Contacts with the rest of the model covering countries – Polish GS,...
More precise data of the Baltic Sea area.
Groundwater flow model: Joining with the hydrological model (for improved surface infiltration
modelling).
Development of the solubles transport and reaction model.
Non stationary groundwater flow calculations (including project activity
PALEO).
Software: Futher development of the vizualisation and automatization tools