Supporting Flood Disaster Response by Freeware Spatial Data in Hungary

Abstract

In Hungary flood disasters are the major natural hazard as a consequence of lowland topographic conditions. Due to both structural and nonstructural mitigation measures from the mid 19^th century, like building dikes and developing adequate warning system, no loss of life was reported since the 1950’s. Nevertheless the value of damage to human property in flood-prone areas may reach millions of euros each year throughout the country. Flood forecast is performed by the national hydrological institute, and warning is transmitted to the local hydrological authorities about the forthcoming disaster. Disaster response measures are based on conventional hydrological information and action plans are developed with traditional methods. The latest technology of GIS and remote sensing is not yet tested in the country to support the spatial information need of disaster response.

The aim of our investigation was to test impact modeling using mostly freely available spatial data. This may ensure feasibility in a case of a future flood catastrophe in various geographic location. The decision of using non-commercial data was further based on the experience that data acquisition from dissimilar sources like local authorizes and the military mapping agency may last weeks or months and was found not suitable for rapid results.

Investigation was based on the recent flood disaster event in the Northern part of the country in the summer of 2004.

To analyze the elements possibly being damaged by the flood, the extent of the inundation was calculated. Flood simulation was executed using digital elevation model of the remotely sensed SRTM radar data and hydrological data from the Hungarian Water Resources Research Centre (VITUKI). Modeled flood extent was serving the basis of spatial analysis of the disaster impact. Settlements hit by the flood disaster were queried. Moreover the condition of flooded road and railway network was analyzed to support route planning of mitigation efforts.

Results of this investigation should help to speed up decision making processes during future disaster events. Moreover should help to reduce property damages and suffering of flood victims.