Steps - How to start? - Step 6

VISUALIZING OTHER CATEGORIES

In this project that we are studying there are other categories. Lets first consider Drainage and Distances.

These categories have a kind of data called thematic. These type of data has the ability to divide the space into themes or classes. For instance, an "Uso do Solo" map, divides the space represented in the map into themes, such as forest agricultural areas, industrial areas, urban areas, or lakes. The data from the "Drenagem" (Drainage) category have this same pattern with just a small difference, not all areas are labeled, but only the ones we are interested on, that is, Lakes and Rivers. All the other themes are set aside, although they exist in the real world. The same method was used to create the "Distancias" (Distancies) category, where only some distance intervals were indicated. All the others were ignored, which creates a generic theme called "background".

The following steps allow to select and to visualize the Information Layers associated to these categories.
 



VISUALIZING THEMATIC DATA

To Visualize the Thematic Drainage Data :

  • click View in the main menu andselect Control Panel, or use the button in the toolbar;
  • select the "Drenagem" (Drainage) category and the IL "Mapa Rios", select the buttons Classes and Lines (see figure below);

  • click the Draw button , so you can visualize the IL selected in main display, which is currently active.

To visualize the "Distancias" Thematic data:

  • keep the IL Mapa Rios selected in the panel
  • select the "Distancias" (Distances) category and the IL "Mapa_dis_Drenagem", select the Classes and the Lines buttons (as it is shown in the IL above);
  • click the Draw button   to visualize both selected ILs in main display.
    NOTE:
    the IL "Mapa_dis_Drenagem" overlaps the IL "Mapa Rios". This happens because it is required to define the visualization priority;
  • activate the IL "Mapa_dist_Drenagem" and change the Priority. An IL priority value less than another means that one will be displayed first in the visualization window;

  • click the Draw button . Notice that the IL "Mapa_dist_Drenagem" is now shown first over the IL "Mapa Rios".

NOTE: Although both ILs belong to the same thematic model, the IL "Mapa Rios" was obtained by manual digitalization from a topographic chart from this area, and the IL "Mapa_dist_Drenagem" was obtained from a SPRING process.

  • unmark both IL selected for visualization clicking twice over the categories "Drenagem" and "Distancias", next another data model will be presented.

VISUALIZING NUMERICAL DATA

Data in this category represents what is known as Digital Terrain Model (DTM). The numerical data category, as designed in the SPRING system, allows association of a numerical value for each point in the terrain considered. For instance: altimetry associates height to each point in the terrain. We are constrained to model just the topography, a numerical category can be used to describe how acid is a soil by indicatng its "Ph" level for each point in the terrain. Different forms of representation can be used in a computer in order to represent a numerical category. It is possible to store numerical data by: Sampling - values are obtained from points in the space or from lines with the same values, Grid - a matriz representing points spread uniformily in space, or TIN - a triangle network used to model a surface.

Lets test each one of these representation forms.

Visualizing the Digital Model Data:

  • click on View in the main menu and enable the Control Panel, option or use the button in the toolbar, if the option is not visible in the main menu.
  •   select the "Altimetria" (Altimetry) category and the IL "Mapa Altimetrico". Mark the Samples check box (as shown in the figure below)

  • click the Drawing button in the tools bar in the main menu to visualize the selected Plan in display 1, which is activated.
  • deselect the Samples option by, unchecking the Samples check box.
  • check now the Grid check box
  • click the Drawing button atalho_desenhar.gif - 941 Bytes
  • deselect the Grid option.
  • select the TIN option
  • click the Drawing button atalho_desenhar.gif - 941 Bytes

You have seen different ways to visualize a numerical Information Layer (IL).


VISUALIZING DERIVATIVE DATA

Numerical data can be processed, and new derivative data can be obtained. In this data base we generate a declive data and, starting from this plan we can generate a declive thematic map indicating declive layers from the terrain. Depending on these declive layers defined at the moment the thematic map was generated, it is possible to define, for instance, adequated areas for construction and other inadequate areas.

You can visualize the existing decliving map after selecting it. The thematic maps can also be respresented using several formats. When it is selected data from categories "Drenagem" (Drainage) and Rede_Viaria, we can see how to visualize data in the vectorial form, produced from polygons, lines, and points. Now we will see how to visualize stored data in a matrix form. In this case it will be presented the indicator Raster in the control panel. Both representation forms are equivalent and can be used indistinctivelly to represent the thematic data. Selecting the best representation will depend on the desired goal, so there is no "best" representation without an aplication. The Spring System allows storage of different representation forms for the same data. The selection of one or other representation will be done depending on the required efficiency related to data manipulation, precision, or even the volume of storage data. In the first trial these details can be neglected.

estrela.gif - 226 BytesVisualizing Derivative Data for a Digital Model:

  • click in View in the main menu and enable the Control Panel, or use the button in the toolbar, if the Control Panel is not visible.
  • select the Declividade category and the IL Mapa_declividade.
  • select the Image button

  • click the Drawing button  atalho_desenhar.gif - 941 Bytes to visualize the required Plan in main display, which is activated.

Note: Thematic models map, like the declive one, can have a legend associated to it, which facilitates the color interpretation used in the map. Click in View - Legend ... in the main menu and click the little triangle button to the left of the IL (see figure below).
 

  • unselect all the ILs selected for visualization with a double click over the corresponding categories, because next it will be seen the cadastral data model.

OTHER VISUALIZATION RESOURCES    VISUALIZING CADASTRAL DATA


 
Topics