The translational landslides result from the combination of favorable conditions when one assumes the existence of functional relations between the spatial distribution of determining factors and processes. Thus, it is possible calculating the probability of occurring these landslides, as well as generating organized maps of susceptibility classes based on the inventory of slip scars and on the variables able to influence their occurrence. Accordingly, the aim of the present study is to analyze the spatial relations between the occurred landslides and a set of potential determining factors, as well as to propose and test susceptibility models based on this analysis. The application of Bayes' theorem of conditional probability using the weights-ofevidence technique allowed analyzing the spatial relations between a set of potential determining factors (geological, geomorphological and soil use and cover factors) and 294 translational landslides in 2008 in the study area. Fifteen different integration schemes of the weighted values, able to reflect the spatial association of each factor in relation to the landslides, were elaborated. The adjustment concerning the spatial independence between the themes and the classification and prediction efficiency of each scheme were analyzed. Three models have met the conditional independence requirements. It was possible identifying that the high-to-very-high susceptibility conditions have varied from 15% (in the model integrating the values of themes such as slope, plan curvature and distance to lineament) to 28% (in the model integrating values of themes such as slope and profile curvature) in Blumenau County Santa Catarina State, based on the selected models.

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Following a small landslide, a large landslide or rockslide occurred on the left (western) slope of the Garcia River, southern Blumenau (Santa Catarina state Southern Brazil) at about 2 : 00 am on Friday, October 23, 2015. The landslide appeared to be controlled by the high-intensity rainfall of 80 mm/2 days and duration rainfall of 354 mm/month in addition to unfavorable geological and geomorphologic settings. Landslide debris destroyed 4 houses at the base of landslide slope and completely dammed the Garcia River with a crest height of about 6.0 m above the streambed. Shortly after the landslide dam formed, the dam was filled completely with water and subsequently failed due to overflow and erosion. By the time of our site visit, the Garcia River has been partially blocked with an estimated water level of about 4.5 m above the streambed, creating a small potential for flash flooding and debris flow at the blockage. On December 3 to 4, 2015, Japan International Cooperation Agency (JICA) carried out an on-site survey, in response to the request of the Department of Geology and Natural Risk Analysis of Blumenau Municipality. The objective of the technical survey was to analyze the risk of landslides and provide some geotechnical recommendations for emergency measures and restoration countermeasure works relative to landslide dam.