Spatial Data Integration for Emergency Services of Flood Management

Abstract

For Romania, as for many European countries, the most damaging geophysical events are floods, which cause significant damage every year over large areas, with the loss of human lives and economic consequences. Flood forecasting, warning and emergency response play important roles ill reducing flood risk during the event. Options for flood risk management range from structural measures, such as raising dikes or channel enlargement, to non-structural measures to reduce exposure and vulnerability. The April 2000 floods in the western part of Romania (Crisuri River Basin) represented the starting point in creating a dedicated system for flood management using Earth Observation (EO) data. Starting from April 2005 this satellite-based surveillance system, connected to a dedicated GIS database, was extended to cover the whole Romanian territory. In order to obtain high-level thematic products, the data extracted from EO images were integrated with other spatial ancillary data (topographical, pedological, meteorological) and hydrological/hydraulic model outputs. A series of specific image processing operations were performed, using the ERDAS Imagine software: geometric correction and geo-referencing, image improvement, statistic analyses, etc. The optical and microwave satellite data supplied by the new European and American orbital platforms like the EOS-AM "Terra" and EOS-PM "Aqua", DMSP, Quikscat, SPOT, ERS, RADARSAT, Landsat7 have been used to identify and highlight flooded areas.This approach is used in different phases of establishing the sensitive areas such as: the database management; the calculation of risk indices from morpho-hydrographical, meteorological and hydrological data; interfacing with the models in order to improve their compatibility with input data; recovery of results and the possibility of working out scenarios; presentation of results as synthesis maps easy to access and interpret, adequate to also be combined with other information layouts resulted from the GIS database. The products which are useful for flood risk analysis include: accurately updated maps of land cover/land-use, comprehensive thematic maps at various spatial scales with the extent of the flooded areas and the affected zones, maps of hazard-prone areas. The satellite-based products contributed to a preventive consideration of extreme flood events by developing plans for flood mitigation, building infrastructure in flood-prone areas and by optimizing the distribution of spatial flood-related information to local and river authorities.