In this QGIS practical the Environment Agency’s flood risk data for Worcester are compared with a 1m resolution Digital Elevation Model (DEM) elevation, collected using LIDAR (LIght Detection And Ranging).
It covers some basic functions and analyses in QGIS, including:
- Adding raster and vector data to a map
- Organising the Layers Panel (Table of contents in ArcGIS)
- Merging multiple raster data tiles to form one raster
- Hillshade analysis for elevation data
- Changing the style/colour/transparency of raster and vector data
- Clipping vector data to a specific object/study area
The tools used are all available in ArcGIS, and the techniques are all transferable and useful whenever you use GIS. Data are available below.
The video lasts for just under 10 minutes and walks through the entire practical, following the steps shown in the PDF guide.
The guide can be downloaded here.
### Before playing the video in the classroom, make sure the volume is muted or that earphones are plugged in so others are not disturbed ###
In keeping with the free-ware theme of QGIS, the data used in this practical are all open-source and freely available.
The backdrop map (Supply format: GeoTIFF Full Colour) and vector data (Supply format: ESRI Shape) are from the Ordnance Survey and can be found here:
https://www.ordnancesurvey.co.uk/opendatadownload/products.html
Elevation data are from the Environment Agency, found here:
http://www.geostore.com/environment-agency/survey.html#/survey
The flood risk zone data can be found on the UK government data site here (download as shapefiles):
Zone 2: http://environment.data.gov.uk/ds/catalogue/#/86ec354f-d465-11e4-b09e-f0def148f590
and Zone 3: http://environment.data.gov.uk/ds/catalogue/#/87446770-d465-11e4-b97a-f0def148f590
Flood defences data are here (again, download as shapefiles):
http://environment.data.gov.uk/ds/catalogue/#/b07dc5b5-f382-4dc1-be4b-464f1e64f12b
GIS, visualisation and mapping 