Working with Maps
Maps are an integral part of all but very simple modeling projects. Their most obvious role is to provide a basis for convenient orientation in the model area. FEFLOW, however, makes much wider use of maps in the modeling workflow. Map geometries can be used to influence the mesh generation process, they can serve to geometrically define the target nodes, elements, edges or faces for parameter assignment, and attributed maps can even provide the input data themselves.
We have to distinguish between raster maps and maps which contain data. Data can be provided in the form of tables or as vector maps if they contain geometry information.
Pixel-based raster maps in formats such as *.tiff, *.jpeg, *.png, or *.bmp can only provide visual information. Vector maps contain discrete geometries (points, lines, and polygons). Formats supported by FEFLOW 8.0 include ESRI Shape Files, AutoCAD Exchange Files, DBase Tables, and several ASCII (text) file formats. In addition to geometrical information these file formats also encompass attribute data, i.e., numerical and/or textual information related to certain geometrical features. While some formats like *.shp support an unlimited number of user-defined attributes, others like *.dxf only allow drawing attributes such as color or line style, and very simple formats such as *.trp (ASCII triplet format—XYF) only support one single attribute value.
Besides the possibility to load separate maps of various file formats, FEFLOW 8.0 also provides the option to connect to different types of geographical databases for data import via the Maps panel and export via the Data panel and View Components panel. The following database systems are supported:
- ESRI Geodatabase
Further details are presented in section Geodatabases.
Tabular data from Microsoft Excel worksheets and Microsoft Access databases can be imported into FEFLOW 8.0 as maps. Export of parameter values and chart data into Excel and Access is supported as well. Supported import and export formats include *.xls, *.xlsx, *.mdb and *.accdb.
Each Excel worksheet needs to be imported as a separate map. For workbooks containing multiple worksheets, the worksheet to be imported is selected via an import dialog.
The import of tables from Microsoft Access databases works similarly. After selecting a database, each table needs to be imported as a separate map via a selection dialog.
Selecting worksheets for import from a MS Excel workbook.
Exported data can either be added as new worksheets or tables to an existing Excel workbook or Access database or they can replace an existing worksheet or table.
ESRI Shape Files, AutoCAD Exchange Files and tabular files (for example, *.dbf, *.dat) may contain three-dimensional map information. FEFLOW 8.0 supports 3D map display in 3D View. The proper display is only achieved by activating Draw 3D Data via the Map Properties panel.
3D map in 3D view window.
FEFLOW - MIKE SHE Integration and Support of FDS2 file
FEFLOW supports the direct import of DFS2 files, for example typically created during MIKE SHE runs. The information available behind the DFS2 file can be linked to any FEFLOW parameter. A common application would be linking MIKE SHE's estimated groundwater recharge into FEFLOW's In/outflow on top/bottom or source/sink parameters. The functionality offers a great opportunity for modelling integrated groundwater resources management and is not limited to only water quantity. Water quality information such as concentration or mass rates behind the DFS2 file format could be utilized as well. Area-weighted projection is a map-data projection method developed to support recharge data import from MIKE SHE, DFS2 files.
Please note that to use this method, you also need to install MIKE SHE on the same PC.
Import DFS2 file.
Dealing with spatial data requires the definition of a unique coordinate system as a reference. FEFLOW 8.0 can use data in any metric Cartesian system, i.e., any system with orthogonal X and Y axes and coordinates in meters. The most popular of these systems is the UTM coordinate system.
To achieve better precision in the calculations, FEFLOW always uses a local and a global coordinate system at the same time. The axes in both systems have the same orientation, only the origin of the local system has an offset in global coordinates.
Locations in the local system can be expressed in Cartesian or Polar coordinates. The coordinate system used in a particular view window can be defined in the View menu. The offset of global and local coordinate system is defined automatically via map extents or manually when starting a new model, but can be edited later on in the Coordinate-System Origin dialog which is accessed with a click on the Edit Origin button in the Origin toolbar. In practical cases, it is usually sufficient to deal with the global coordinate system.
In 2D cross-sectional and axisymmetric models the Y coordinate refers to the elevation. In these cases an offset between local and global coordinates in Y should be avoided so that there is no doubt about the elevation reference. Internally, FEFLOW 8.0 uses the local Y coordinate as the reference for elevation-dependent parameters, e.g., when converting Hydraulic head to Pressure head and vice versa.
Global and local coordinates (2D/3D).
The WGEO software provided with FEFLOW 8.0 can add a geographical reference to raster images such as scanned maps in *.tiff, *.jpeg, *.png or *.bmp format for use as maps in FEFLOW 8.0. WGEO can also perform coordinate transformation for raster and vector maps applying a 7-parameter Helmert transformation routine.
In Plus mode (separate licensing required), WGEO also provides functionality for georeferencing of ESRI Shape Files (*.shp) and AutoCAD Exchange Files (*.dxf). Additional coordinate transformation routines are also available.
Please refer to the WGEO manual and its help system for a detailed description of the respective work flows.
The Maps panel is used to load and manage raster and vector maps as well as database connections. Available formats are
Raster maps: *.tif, *.jpg, *.png and *.bmp
- Vector maps: *.shp, *.lin, *.ply, *.pnt, *.trp, *.ano, *.dxf, *.smh, *.dbf, *.dat, *.pow, *.xml, *.xls, *.xlsx, *.mdb and *.accdb.
To open a connection to a geographical database, an *.fedb file needs to be loaded. In case of tabular data, the columns containing coordinate values have to be chosen at the time of import, unless they correspond to some defaults like X, Y and Z.
The available supermesh (polygons, lines and points) of the current model is also displayed as map data in the panel.
Using a naming convention of X, Y and Z as column headers for the geographical coordinates is recommended in the tabular data of a map file in FEFLOW. This will facilitate the immediate display of the map information in the FEFLOW views.
By default, maps are sorted according to their format in the Maps panel. For more convenience especially in large projects, the tree structure can be customized according to the user’s needs:
- The order of folders and maps within a folder can be changed by drag and drop and maps can be moved to different folders.
- Existing folders can be renamed by pressing <F2> or via their context menu and new folders can be created via the context menu of the Maps panel or by clicking on the search icon at the top of the panel.
- The search bar at the top of the Maps panel allows to filter map and folder names by a full-text search.
The relative map locations and all map settings can be stored with the FEFLOW map reference file (*.mre ) files.
and thus easily be transferred between different FEFLOW models. Export is available for folders and maps, while the import option is limited to folders.
FEFLOW 8.0 allows the quick import of map files by a drag-and-drop operation. For example, the user can simply drag map files from the Windows Explorer and drop them into the FEFLOW graphical interface. For this operation few rules need to be remembered:
- There must be a FEFLOW document (FEM File or DAC File) already loaded in the graphical interface.
- Only supported map files can be dropped into the interface. Any other file will be ignored.
- An arbitrary number of maps can be dropped at once. It is also supported a combination of several file formats.
- Map files can be dropped anywhere in the graphical interface.
- If maps are dropped in any FEFLOW view, they will be automatically added to the view (i.e. displayed) and also annexed to the View Components panel. The display will be done by using the default styles.
While raster maps already contain information about the display color for each pixel, this is typically not the case for features in vector maps. The display information for these kinds of maps is contained in so-called layers. When loading a map, FEFLOW creates a layer named Default with just one single style (color, line style, etc.) applied to all features in the map. The properties of the default layer can be edited, and additional layers can be added by using the functions in the context menu of the layer and the map. All layers of a specific map can be exported into an *.fml (FEFLOW map layer) file via the context menu of the map. The map layer file can then be used to import all layers to the same or a different map in the same or a different FEFLOW model.
The properties of a map layer can be edited in the Map Properties panel which is opened via the context menu of the layer. Basic settings such as opacity, lighting options and 3D drawing options can be applied to all features of the map. The map can be classified based on one of the attribute fields of the map either by applying a different style to each unique attribute value, or by partitioning the overall range of values of a numeric attribute into a number of classes. Predefined color palettes are readily available to be applied to the classes or unique values.
Color and other styles can also be edited manually for any individual class or for a selection of multiple classes.
Via the context menu of a map layer, all styles can be exported into an *.fms (FEFLOW map style) file and imported again for a specific map layer.
Map Properties panel.
Vector maps or databases can be applied as a basis for data assignment or data regionalization, deriving the basic data directly from the map file. For details on the assignment of map data, please refer to section Parameter assignments.
The attribute data of vector maps or database files can be shown via Show Map Table in the context menu of a map. The Map Table dialog will display the different records and attribute data contained in the map in tabular format.
Map Data Selection/Map Joining
Besides using the entire data range provided in a map, it is possible to use only selected map data. To limit the data range of a map, SQL selection statements on attribute data can be used via Join/Select Map(s) Data in the context menu of a map.
The option Join/Select Map (s) Data also provides the possibility to join additional data tables to a map, using a common identifier in both tables.
For tables imported from a geographical database, the context menu of the table header in the Join Maps dialog can be used to display the defined relationships with other tables of the database. Selecting a defined relationship automatically imports the corresponding table and relation.
All the model properties and results can be exported to different kinds of map files, retaining the geographical reference of the model.
Export of parameters is invoked via the context menu of the parameter in the Data panel, or via the context menu of the parameter in the View Components panel. Both export for the entire model domain and for the selected geometries or the values in the current slice/layer only are supported. In a results (*.dac) file, process-variable results can be exported for the current time step or for all or a selection of time steps.
Visualization options such as isolines or fringes can be exported to a map file via the context menu of the visualization style in the View Components panel.
Exported maps can automatically be loaded to the Exported Maps section within the Maps panel of the current FEFLOW model.
The Quick Import option can be used to assign data of a previously exported map to several parameters at once without the need for defining parameter links via the Parameter Association dialog first. The import can be limited to specific model parameters and/or to the current slice/layer or the current selection. To match the input data to the mesh elements or nodes, different selection methods are available.