ASSESSMENT OF FOOD HAZARD AND RISK USING GIS AND HISTORICAL DATA. CASE-STUDY: THE NIRAJ RIVER BASIN (TRANSYLVANIA DEPRESSION, ROMANIA).

The intensification of extreme events, due to global climatic changes and irrational land use, has materialised in the change of pluvial regime and high precipitation amounts. Thus, the study of flash floods, as a result of the rain-flow process, has an important place in applied hydrologic research. Floods represent a hazard with high frequency and magnitude in Romania, especially on rivers originating in the Carpathian mountain area, with pluvial and nival source. Therefore, the quantification of flood vulnerability and risk is necessary for a better management of priorities in emergency situations. The flood risk zonation is made in applied hydrology through floodable stripes, which are produced using statistical analysis of past data series and their integration in determinist spatial analysis models. The aim of the present study is to identify the flood risk and the vulnerability of infrastructure by determining the floodable stripes of the main river in Niraj basin, where significant damages have been recorded after flash floods. In order to achieve this, the methodology included a statistical analysis of hydrologic probability using recordings from the last 43 years (1970-2013), as well as field measurements (topographic profiles used as computational sections) integrated in GIS databases and complex spatial analysis models. The results of the spatial analysis model are illustrated through the flood risk map, generated as a product of temporal flood probability and vulnerability of the territory. These results can be successfully used in territorial planning projects and in the management of emergency situations, but can also be included in other spatial analysis models of flood risk. [ABSTRACT FROM AUTHOR]