BEng Project: Avalanche Hazard Visualiser

An app to visualise avalanche hazards in Scottish mountains, using data from Ordnance Survey and Scottish Avalanche Information Service, a complex system programmed in Python, MATLAB, JavaScript and many other languages.

Installation

This system is to be deployed on an Ubuntu 14.04 LTS or 16.04 LTS system.

Locations of the height map and aspect raster files are defined in GeoData/raster.py, change them as necessary before proceeding. The system requires the following rasters computed in QGIS:

• HEIGHT_RASTER: height map DTM raster.
• ASPECT_RASTER: terrain aspect map raster, computed by gdaldem.
• CONTOUR_RASTER: a useful overlay map from an OS 1:25000 map raster.
• RISK_RASTER: static risk raster computed by Computations/static_risk.m, which in addition to ASPECT_RASTER requires a raster of terrain slope (by gdaldem) and a raster of curvature (by r.slope.aspect from GRASS).

Initial deployment requires root.

Install system-level dependencies:

    apt-get install python-setuptools python-pip virtualenv nginx

Install uwsgi with pip at system level (system package may be broken at this time):

    pip install uwsgi
    which uwsgi # Check that it is indeed /usr/local/bin/uwsgi or you may need to change terrain_api_server.service or terrain_api_server.conf in Scripts/

Build GDAL 2 since we only have GDAL 1 in the official repository:

    wget http://download.osgeo.org/gdal/2.1.3/gdal-2.1.3.tar.gz
    tar zxvf gdal-2.1.3.tar.gz
    cd gdal-2.1.3
    apt-get build-dep gdal
    ./configure --prefix=/usr/
    make && make install

Download Cesium and place it in a directory for NGINX:

    mkdir /home/cesium
    cd /home/cesium
    wget https://cesiumjs.org/releases/Cesium-1.30.zip
    unzip Cesium-1.30.zip

Suppose the project directory is /home/BEngProject and the Cesium web directory is /home/cesium.

Remove the original index.html and Terrain.html, replace it with ours:

    cd /home/cesium
    mv index.html index.old.html
    mv Apps/Sandcastle/gallery/Terrain.html Apps/Sandcastle/gallery/Terrain.old.html
    ln -s /home/BEngProject/Cesium/index.html /home/cesium/index.html
    ln -s /home/BEngProject/Cesium/Terrain.html /home/cesium/Apps/Sandcastle/gallery/Terrain.html

Now copy over the configuration files for uwsgi. For 14.04 LTS with upstart, this is:

    cd /home/BEngProject
    ln -s /home/BEngProject/Scripts/terrain_api_server.conf /etc/init/terrain_api_server.conf

For 16.04 LTS with systemd:

    cd /home/BEngProject
    ln -s /home/BEngProject/Scripts/terrain_api_server.service /etc/systemd/system/terrain_api_server.service

Adapt the NGINX virtual host configuration Scripts/avalanche.ebornet.com for your needs, particularly the locations of TLS certificates you use. Then link the configuration for NGINX:

    ln -s /home/BEngProject/Scripts/avalanche.ebornet.com /etc/nginx/sites-enabled/avalanche.ebornet.com

Now to configure python environment:

    cd /home/BEngProject/Backend
    virtualenv env --system-site-packages
    source env/bin/activate
    easy_install GDAL # The only way to correctly install the Python bindings at this time.
    pip install -r DEPENDENCIES #Install the dependencies.
    deactivate

Set permissions:

    chown -R www-data:www-data /home/BEngProject /home/cesium

Now to start all services, for 14.04 LTS with upstart:

    sudo start terrain_api_server
    # Check /var/log/upstart/terrain_api_server.log for any problems.
    sudo nginx -t #Test config
    sudo service nginx restart

For 16.04 LTS with systemd:

    sudo systemctl start terrain_api_server
    sudo systemctl status terrain_api_server #Check for any problems.
    sudo nginx -t #Test config
    sudo systemctl restart nginx

Any problems with installation should be indicated in the relevant logs.

SAIS Crawling

Due to the lack of a public API, the system crawls SAIS pages for avalanche forecasts and past avalanche records. The enabling facilities can be found in /Backend/SAISCrawler, with scripts to execute this process automatically.

At the time of writing (Dec 2017), while the OSX script works, something is broken with Xvfb and Chrome Driver such that selenium will return an error of abnormal Chrome exit. Some changes may be needed to get the Linux script working again.