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Istituto Scienze della Terra - SUPSI

Demo dataset

Demo dataset description

First of all, let us thanks the Regione Autonoma della Sardegna for having kindly provided the data for this lab wich is a portion of Olbia city in Sardinia.

Data are provided in the UTM – Zone 32N (6 – 12° West) in WGS 84 (World Geodetic System 1984) coordinate system, within the region bounding box N=4530358 - S=4529364 - W=541054 - E=542604 and with a raster resolution of 2m.

In order to import the raw data into GRASS you should have defined a location with the above coordinate system (EPSG=32632) and region definition.

The following data are available in the demo dataset (note that by usign the SlaxGIS data are already loaded into the location Italy):

1. Digital terrain model (DTM)

Originally obtained from LiDAR filtered data and the nearest neighbour algorithm, has been re-interpolated on the same grid by using r.surf.bspline in order to obtain a smoother version.

Data are stored as X|Y|Z in ascii format:

therefore the r.in.xyz command has to be used for import in GRASS:
r.in.xyz input=/yourpath/dtm.xyz output=dtm 
 
 

2. Digital surface model (DSM)

It is in GRASS grid ascii format with the following header:

In order to import the digital surface model, use the following command:
r.in.ascii input=/yourpath/dsm.txt output=dsm 

3. Landuse

It is available in ARCinfo ASCII GRID format with the following header:

 
to import the data use the following command:
r.in.gdal -o input=/yourpath/corine.asc output=corine
 
Note that the landuse map uses the CORINE classification that for the Sardinia region includes the following categories:
111:Continuous urban fabric
112:Discontinuous urban fabric
121:Industrial or commercial units
122:Road and rail networks and associated land
123:Port areas
133:Construction sites
141:Green urban areas
142:Sport and leisure facilities
243:Agriculture
322:Moors and heathland
323:Sclerophyllous vegetation
521:Coastal lagoons

And therefore in order to associate the categories, a text file (category.txt) with the above lines must be created and the following command is used:

r.category map=corine rules=/yourpath/category.txt

4. Buildings

This layer are available in ESRI Shapefile format. With respect to the original data provided from Regione Autonoma della Sardegna, this layer has been enriched by adding the number of floors of the single buildings (the value has been estimated by considering the mean building height derived from LiDAR measurements and considering a "standard" height for a floor corresponding to 3.5 meters). Moreover the area of the buildings has been computed and added.

The resulting attributes of building entities are:

The import of this data can be achieved trough the following command:

v.in.ogr -o dsn=/your_path/buildings/ output=buildings layer=buildings