ABSTRACT
This chapter proposes a method for regional assessment of debris flow susceptibility under limited availability of data in urban environments, where flash floods occur as debris flows, hyperconcentrated flows or clear water flows as defined by Costa. Variability in the level of hazard is reflected in the proposed susceptibility index, where high values represent a higher potential for debris flow and therefore an increased hazard condition. The land cover indicator was constructed by analysing the characteristic land cover of each watershed, which was obtained from the classification of a LANDSAT TM5 image taken in 2001. Morphometric parameters used in literature were extracted for each watershed from the digital elevation model of the study area using ArcGis, SAGA and R functions. The resulting indicators of land cover and morphometry were combined using a matrix that allows classification of the catchments into high, medium and low susceptibility.
