Maps relating to volcanic activity may show pre-existing lava and pyroclastic flows, vents and craters. They may also show other associated hazards such as new lava flows, volcanic gas, lahars, jökulhlaups and pyroclastic flows. Decision-makers will be looking to identify possible evacuation routes from these maps.
Both
Basemap and situational.
Pre-existing geological maps may already exist and these can be used early on. As the situational data arrives it is important that the maps are updated. This is particularly the case where volcanic gas and ash clouds are present and there is wind and rain in the area, which will influence which direction the ash will carry and how much is in the air.
Civil defence and anyone involved with evacuation.
Decision-makers are going to be interested in identifying evacuation routes and safe zones. Basemaps may show pre-existing lava and pyroclastic flows, vents and craters. Volcanic hazards that may need to be mapped or may influence decision-making include:
Create distance buffers around the volcano. These can then be used to identify villages and communities possibly within reach of gas and ash clouds. Distance products depicting the spread of gas and ash can be produced by using wind direction and speed.