# Geovisualization Techniques of Spatial Environmental Data Using Different Visualization Tools
## 3 Results of Visualization
### Advantages and Disadvantages of Tools  
The most important benefits of 2D or 3D spatial data visualization performed via QGIS modules that the geoinformatics processing and publication of spatial environmental data imported into the system (database management, styling, layer handling, analysis) can be performed using one interface and there is no need for post-processing on another platform or in a different software environment. A further advantage is that it can interpret most of the raster and vector file formats and carry out the conversions between systems, as a result of which, users are able to visualize complex spatial analyses without coding skills. Since in the case of Cloud module, a server is not required for web publication, the results are available for everyone after processing, however due to a limit for upload, the visualization of large databases is possible only by paying for a greater storage capacity. In the case of Qgis2 threejs module, there is no such data limit, however, a web server is required for the publication of data. In the context of 3D data visualization, we considered a drawback that beside the installation of the extension needed for displaying the contents in the browser, it is important that the size of the input data makes loading the data slower.  
The advantage of using KML for 2D data visualization in addition to Google Earth and Google Maps is that, it is supported by other geoinformatics applications. Google Earth processes a KML file in a similar way that web browser process HTML and XML files. Similar to HTML, KML also applies indicators with name and attributes for specific displaying purposes. In this aspect, Google Earth act as a browser for KML files, however, Google Maps cannot display every item of KML. Google maps--beyond the general browsing functions--allows users to insert web maps into their own website or link this own database to the contents of the map. To make the best out of this feature, freely accessible APIs (Application Programming Interfaces) are provided for the user as long as he/she possesses basic JavaScript coding skills. Google APIs are fundamentally a native JavaScript interface which can be used to control the functioning of the map (e.g., map type, layer management, size, KML management etc.). Also, its helps managing the KML files so that all its functions can be used. The drawback of its application is that the visualization of data requires programming skills, complex analyses cannot be performed and similar to QGIS, a web server is necessary for the web publication of data.  
With regards to the environmental data used and processed in the study, it should be emphasized that thanks to the raw data from the measurements and the freely accessible databases (OSM, ASTER GDEM) the end user can query the attributes of the investigated wells, thereby facilitating the local interpretation of the studied phenomenon creating a new, innovative perspective of map usage.  
Beside the numerous advantages of the technologies presented (event management support, no need for extension for insertion etc.) we can also find factors which limit the visualization of KML items (formatting limitations, default display, etc.) and raster data. Despite the uploading/displaying data limits of the devices, these allow the publication of smaller databases, especially the resource-intensive server-side application and services offered for payment. Considering the above, it can be concluded that the application of freely accessible geovisualization tools nowadays is sufficient for the web publication of geographical data. Table 1 summarizes the evaluation aspects of the tools.