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spatial_analysis:settlements_and_landscape [2007/10/01 16:08]
steko histograms, results
spatial_analysis:settlements_and_landscape [2018/08/04 00:01]
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-====== Settlements and landscape: analysis techniques ====== 
  
- 
-===== Input Data ===== 
- 
- 
-  - A raster DEM of the studied territory. You can obtain an aspect map from it using the ''​r.slope.aspect''​ module. 
-  - A vector map of sites or buildings dating from a defined period. 
- 
-===== The steps to the analysis ===== 
- 
- 
-Convert the vector map to raster with the command: 
-<​code>​v.to.rast input=edifici output=edifici.mask use=val layer=1 value=1 rows=4096</​code>​ 
- 
-Remember that this conversion is run following the region settings. You can view the region settings with: 
-<​code>​g.region -p</​code>​ 
- 
-Now the resulting raster map becomes our ''​MASK'':​ 
-<​code>​r.mask input=edifici.mask maskcats=*</​code>​ 
- 
-From now on, all subsequent operations will be limited to the cells defined in our ''​MASK'',​ corresponding to built 
-areas or settlements. 
- 
-The simplest analysis we can run is ''​d.histogram''​. These are the histograms of **elevation** and **aspect** for the whole of our study area. Aspect is calculated counterclockwise from east, thus 0 = 360 = E, 90 = N, 180 = W, 270 = S. See http://​grass.itc.it/​grass62/​manuals/​html62_user/​r.slope.aspect.html for the manual page of ''​r.slope.aspect''​. 
- 
-{{spatial_analysis:​nomask.elevation.jpg?​300|}} 
-{{spatial_analysis:​nomask.aspect.jpg?​300|}} 
- 
-Applying ''​built.areas''​ as ''​MASK''​ results in these histograms: 
- 
-{{spatial_analysis:​mask.elevation.jpg?​300|}} 
-{{spatial_analysis:​mask.aspect.jpg?​300|}} 
- 
-===== Results ===== 
- 
- 
-This simple exploratory analysis leads us to understand that in the study area there'​s a strong preference for sites exposed S-SE, built mostly around 700 meters above sea level. 
spatial_analysis/settlements_and_landscape.txt ยท Last modified: 2018/08/04 00:01 (external edit)