Run-out analysis

The driving force for all types of landslides is gravity. The terrain model and 3D analyses based on this will therefore be a very important factor in the assessment of exposed areas. NGI has both implemented its own run-out analysis directly in ArcGIS and integrated with external run-out analysis software packages. One example of a run-out analysis NGI has implemented directly in ArcGIS is the a / ß model. The a / ß model is NGI's self-developed outlet model for avalanches.

The quality of the terrain model governs how accurately the danger zones for landslides and rockfalls can be assessed. NGI has experience in using most types of source data for generating terrain models. The most common sources for terrain data are terrain elevations, raster and point clouds from laser scanning.

NGI 3D Analyse fig 1

The picture shows the results of a run-out analysis for avalanches in GIS based on NGI's in-house developed Alfa-Beta method together with the resulting danger zones for avalanches. 

Deposit design

Planning of new and further development of old landfills is done on the basis of existing or self-collected terrain data. The quality of the terrain data is important in order to obtain realistic information of the landfill volume, at the same time as it is important for the planning of, among other things, the drainage in the landfill.

Terrain models from laser scanning are in such cases the most accurate and the absolute preferred. When designing the landfill, several alternatives for filling and covering are often studied, at the same time as the landfill is visualized in 3D.

NGI 3D Analyse fig 2

Avfallsdeponi med mektighet av lagringsmassen.

3D visualization

Most phenomena modelled in 3D can also be visualized in 3D. The example below is the visualization of the deepwater landfill at Malmøykalven in the Oslo Fjord. The display is made in ArcGIS and shown in ArcScene.

The measuring stations and the simulation of the sludge distribution are all georeferenced and shown together with detailed bathymetry from the area.

NGI 3D Analyse fig 3

The deepwater landfill at Malmøykalven in the Oslo Fjord. MP2-4 shows buoys and measuring points for turbidity. Orange "cloud" shows measured and interpolated distribution of water with sediments.

NGI's expertise

  • integration in GIS with external software packages for 3D analysis
  • use of different types of terrain models, including point clouds from laser scanning
  • terrain and volume analysis
  • visualization in 3D