In this paper a method is proposed to identify mountainous watersheds with the highest flood risk at the regional level. Through this, the watersheds to be subjected to more detailed risk studies can be prioritised in order to establish appropriate flood risk management strategies. The prioritisation is carried out through an index composed of a qualitative indicator of vulnerability and a qualitative flash flood/debris flow susceptibility indicator. At the regional level, vulnerability was assessed on the basis of a principal component analysis carried out with variables recognised in literature to contribute to vulnerability, using watersheds as the unit of analysis. The area exposed was obtained from a simplified flood extent analysis at the regional level, which provided a mask where vulnerability variables were extracted. The vulnerability indicator obtained from the principal component analysis was combined with an existing susceptibility indicator, thus providing an index that allows the watersheds to be prioritised in support of flood risk management at regional level. Results show that the components of vulnerability can be expressed in terms of three constituent indicators: (i) socio-economic fragility, which is composed of demography and lack of well-being; (ii) lack of resilience and coping capacity, which is composed of lack of education, lack of preparedness and response capacity, lack of rescue capacity, cohesiveness of the community; and (iii) physical exposure, which is composed of exposed infrastructure and exposed population. A sensitivity analysis shows that the classification of vulnerability is robust for watersheds with low and high values of the vulnerability indicator, while some watersheds with intermediate values of the indicator are sensitive to shifting between medium and high vulnerability.

Increasing interest in thermo-hydro-mechanical (THM) studies of soil responses to hydrological variations has heightened the need for improvements in the basic understanding of the heat and mass transport taking place at the soil-atmosphere interface. Numerous hydrological parameters affect this thermo-hydro-mechanical process including solar radiation, air temperature, atmospheric pressure, wind velocity, rain intensity and hygrometry. Since field tests of soil-atmosphere interaction require measurements over long periods of time, only a small number of these results are available for calibration of the numerical models that are based on atmospheric data as boundary condition. The number is even more limited for results which focus on cyclic wetting and drying. Centrifuge modeling is a powerful tool for studying these problems since it can accelerate the time needed for diffusion processes taking place at the soil-atmosphere interface. Nevertheless, modeling this interaction adequately with a centrifuge requires development of new types of equipment such as a climatic chamber that allows control of weather variables while respecting the centrifuge’s scaling laws. This paper describes the design of an apparatus for simulating tropical weather conditions which combines a climatic chamber with a centrifuge. The scaling laws are studied, and the feasibility of reproducing tropical weather conditions around a centrifuge is discussed. Finally, the paper presents some validation results that highlight the working principles of this new apparatus.