Installation Manual | GRASS GIS Addons r.viewshed.exposure and r.viewshed.impact¶

Computer specifications¶

The tools r.viewshed.exposure and r.viewshed.impact were run on a server with the following specifications (Table 1).

Table 1. Computer specifications.

	Visual Exposure	Visual Impact
Server	HPE ProLiant DL360 Gen 10	HPE ProLiant DL360 Gen 10
Processor	2 Intel ® Xeon ® Gold 6134 CPU @ 3.20 GHz Central Processing Units	2 Intel ® Xeon ® Gold 6134 CPU @ 3.20 GHz Central Processing Units
CPU cores	40 cores	40 cores
Random Access Memory	370 GB	377 GB
SSD	960 GB	960 GB
Fie System	Ubuntu 18.04.5 LTS	Ubuntu 18.04.5 LTS

Table 2. Time used for r.viewshed.exposure processing.

Municipality	Processing time
Bodø	211 min
Bærum	692 min
Kristiansand	58 min
Oslo	2078 min (34 hours 38 min)

The r.viewhsed.impact tool is more computationally demanding than r.viewshed.exposure. Due to resource restrictions, the tool was solely run on a test-site for the municipality of Oslo.

Install GRASS GIS with Docker¶

Pull official OSGEO GRASS

docker pull osgeo/grass-gis:releasebranch_8_3-ubuntu_wxgui

Enter container from Command Line Interface (CLI)

docker run -it osgeo/grass-gis:releasebranch_8_3-ubuntu_wxgui

Enter Container from Visual Studio Code

CTRL + ALT + P
add the .devcontainer.json to your .devcontainer folder

Inside your container start GRASS

grass
g.gui wxpython

Install GRASS GIS Addons¶

Official GRASS documentation on how to install addons is available HERE.

Using GRASS GUI¶

Settings > Addons Extension
Search for extension
Install
Check that extension is installed

Using GRASS CLI¶

# check if addonn is already installed 
g.extension -a 
g.extension -a | grep "r.viewshed.exposure"

# install extension using GRASS CLI 
g.extension extension=r.viewhsed.exposure

# install from GITHUB
# r.viewshed.exposure is part of grass-addons
g.extension extension=r.viewshed.exposure url=https://github.com/OSGeo/grass-addons/tree/grass8/src/raster/r.viewshed.exposure

# r.viewshed.impact is unreleased addon
g.extension extension=r.viewshed.impact url=https://github.com/zofie-cimburova/r.viewshed.impact 

Install GRASS GIS Addons as a local module¶

In case you want to modify the code of the addon or you want to use an unreleased addon, you can install the addon as a local module.

# clone the addon code from GITHUB
git clone https://github.com/OSGeo/grass-addons.git grass-addons
git clone https://github.com/zofie-cimburova/r.viewshed.impact r.viewshed.impact

# install the addon by pointing to the local folder
g.extension extension=r.viewshed.impact url=/path/to/local/git-repo/r.viewshed.impact/

GRASS GIS Tasks used in this project¶

Note that processing costs a large amount of resources and time (Table 1 and 2). Therefore scheduling the tasks and disucssing resource allocation with your IT department is recommended.

Using GRASS GUI¶

Create new GRASS database GRASS GIS Database - GRASS GIS Manual (osgeo.org)

New database > your grassdata directory
Name your location folder UTMxx or WGSxx
Set your EPSG code
- 25832 (UTM32)
- 25833 (UTM33)
Apply transformation.
Finish

Import data into your GRASS Mapset

Import dsm_dtm
Import treecrown binary raster
Import treecrown vector
Import public space binary raster
Import private space binary raster

Set computational region

Settings
Computational region
Set region [g.region]
Set elevation model as g.region

Run r.viewshed.exposure tool

Tools
Search for r.viewshed.exposure
Fill in parameters

Run r.viewshed.exposure tool

go to Python console
import local grass.script
click run > GUI opens fill in params

Export results

File > Export raster map (visual exposure raster)
File > Export vector map (tree crowns with public/private visibility values)

Using GRASS CLI¶

# create new grass database
mkdir /path/to/dir/grassdata

# start grass session
grass /path/to/dir/grassdata

# create new grass location
grass -c EPSG:xxxxx /grassdata/new_location
grass -c EPSG:25832 /workspaces/urban-tree-visibility/grassdata/utm32

# init existing grass session 
grass /path/to/grassdata/location

# check if addonn is installed 
g.extension -a 
g.extension -a | grep "r.viewshed.exposure"

# install r.viewshed.exposure 
g.extension extension=r.viewshed.exposure

# install r.viewshed.impact as a local module
git clone https://github.com/zofie-cimburova/r.viewshed.impact r.viewshed.impact

# install the addon by pointing to the local folder
g.extension extension=r.viewshed.impact url=/path/to/local/git-repo/r.viewshed.impact/

# Set computational region 
g.region raster=dsmdtm_1m_utm32_flt@$MAPSET -p

# Run r.viewshed.exposure tool
r.viewshed.exposure input=dsmdtm_1m_utm32_flt@oslo output=visual_exposure_1m_utm32 source=treecrown_1m_utm32_int@oslo range=100 function=Distance_decay sample_density=25 seed=1 memory=200000 nprocs=40

# Export visual exposure raster
r.out.gdal input=visual_exposure_1m_utm32@oslo output=path/to/output/visual_exposure_1m_utm32.tif format=GTiff type=Float32 nodata=-9999

# Run r.viewshed.impact tool
r.viewshed.impact exposure=treecrowns@impact column=v_public dsm=dsmdtm_1m_utm32_flt@impact weight=public_space_1m_utm32_int@oslo_impact Range=100 seed=1 memory=200000 cores_e=10 cores_i=20

# Export tree crowns with public/private visibility values
v.out.ogr input=treecrowns@impact output=path/to/output/treecrowns_public_private.shp format=ESRI_Shapefile type=auto