Rapid Mapping

In figure 1 the typical rapid mapping workflow of ZKI during crisis situations is illustrated. After the disaster the initial mobilisation phase follows. Civil protection offices, situation centers or decision makers receive information regarding the occurrence of a crisis event and trigger ZKI activities either directly or indirectly through authorised users.

ZKI starts directly its activities by tasking earth observation satellites that may provide relevant crisis data. In addition, the data archive is searched for matching pre-disaster satellite scenes. During the first 6 hours after the activation of ZKI, reference maps based on archive satellite data providing a first overview of the affected area can be made available to relief organisations. The newly acquired post-disaster satellite data is used to assess and monitor the ongoing crisis situation, i.e. delineate the affected areas and estimate the damages caused by the disaster.

After the satellite data has been downlinked and received by ZKI, data pre-processing takes place which includes tasks such as its projection to a coordinate system or its fusion with other data sets. Subsequently, various algorithms and processing chains tailored to the type of catastrophe (e.g. change detection, damage assessment or thematic analyses such as flood or burned area mapping) are employed to extract the requested crisis information. The results are integrated into map products or other product formats. For the purpose of map production, additional interpretation texts, legends and overview maps are generated. Upon completion, the crisis products are transferred to the user free of charge, either through the ZKI website, via ftp-server, email or by providing map print outs.

Past rapid mapping activations of ZKI cover a broad range of thematic areas, such as natural and environmental hazards (floods, hurricanes, fires, earthquakes, oil spills) and humanitarian relief activities (e.g. mapping of refugee camps).

Figure 2 shows an example of a ZKI detail map of an embankment breach and related floods in Nepal, August 2008. Data from the German radar satellite TerraSAR-X were used to derive the flood extent. Based on the analysis, the length of the breach could be approximated with 1400m. The map also illustrates flooded road segments (orange) and buildings as well as agricultural areas fully surrounded by water (yellow).