Due to the fact that spatial data is stored in different formats, and in order to be able to work with them many times, we have to convert them from one format to another. This paper presents the transformation of dwg files into ESRI shapefile format. Any DWG file can be considered as a database of 2D or 3D drawings designed in the CAD work environment, such as AutoCAD. These types of programs contain vector images and metadata that describe the content existing within the file. DXF files are ACII versions of DWG files. ESRI shapefile extension is a spatial data structure, based on the generation of each spatial theme in a single vector format, be it point, line or polygon format. These data are easy to manage from the point of view of adding / deleting and formatting the supported columns. Using annotation is an option in ArcGIS software in order to store text to place on the maps. In other order, the annotation can be used in order to describe a particular feature or to add some other information to the GIS map. With the annotation, the text string with the position and the display properties are record together and can be editable individually. Annotations that are feature-linked are associated with a specific features in another feature class in the geodatabase. If it is checked, when it is creating the output annotation feature class, it will be automatically generated a relationship class. This particularly relationship class it define the relationship that exist between the annotation and the features and it enables to define and customize this relationship but it won’t establish the connections and the links between features and annotation. By definitions of GIS and CAD, it can be said that a GIS software can be related to digital maps and a CAD software can be related to objects. In other words we can say that to represent a line (e.g. :road, rivers) a GIS software must be used but to design a bridge a CAD software must be used. The most important differences between a GIS and a CAD software are: a GIS software necessarily requires a spatial reference and a CAD can dispense with it; in a GIS software the scale can be change very simple, in a CAD software to change the scale can be problematic; GIS data’s are stored in multiple files (shp, prj, dbf), while a CAD data can be stored in a single file; GIS applications are using a common terminology (e.g. a layer is the same in any GIS software (QGIS, ArcGIS, Envi), but in CAD some terms may conflict. In a GIS, analaysis predominates, a CAD places greater emphasis on detail and precision (e.g. the design of town elements); any GIS software is very efficient in order to managing databases but it is not a strenght of a CAD.

Geographical Information System - GIS, DWG, Shapefile, Conversion

environmental engineering

Presentation: poster