Using the shakemap importer tool in InaSAFE
“The shakemap importer tool provides a quick way to generate an earthquake raster hazard dataset from a USGS grid file.”
InaSAFE can work with earthquake hazard datasets. These data are usually created by a network of seismic sensors that send shake levels back to a central server which then runs a model to generate a grid file (a USGS Grid File). This file is in XML format and cannot be read directly by QGIS or other GIS software. The grid file is usually made available by government agencies soon after the shake event. InaSAFE can convert this file into a single band raster layer which can then be used to run InaSAFE analyses.
You try:
Goal: To generate an earthquake hazard layer from a shake grid dataset and use it in an analysis.
- Use the Shakemap Converter (there is no toolbar icon for it so look in the Plugins -> InaSAFE submenu) with options as indicated on the table below.
- Note Bhutan data may be used for this exercise from the provided course resource.
| Input | value |
|---|---|
| Input file | grid.xml |
| Title | Training with shake data |
| Source | InaSAFE contrived data |
| Output | Leave unchanged |
| Add output layer to QGIS project | Yes |
| Launch Keyword wizard | No |
| Algorithm | Nearest Neighbour |
- When the layer is added to QGIS, zoom to the whole layer.
- Review the keywords created for the layer and see if you can understand them.
- Add the buildings layer from your exercise-data directory.
- Run an analysis to see what the impact of the earthquake might be on buildings.
Check your results:
How many buildings were affected in each hazard zone? Do your results match your neighbour’s?
More about
The goal of the shakemap (grid.xml) importer tool is to make it easy to convert shakemaps into usable hazard data in InaSAFE. The input data is in a format that cannot be directly opened by QGIS, so during the conversion process, it will be converted to a GeoTiff single band raster image. The converter will also assign a QGIS style to the converted image so that it is easy to interpret visually.
Shakemaps are published and freely available by the USGS (and National Institutions in other countries) soon after earthquake events happen at https://earthquake.usgs.gov/data/shakemap
Check your knowledge:
-
InaSAFE does not use grid.xml files directly:
- True
- False
Further reading:
-
See the shakemap importer tool section in the InaSAFE user manual at: http://manual.inasafe.org/en/index.html#shakemap-converter
Download the sample data for the lesson.