A general methodology for the probabilistic evaluation of landslide hazard is applied, taking in account both the landslide susceptibility and the instability triggering factors, mainly rainfall. The method is applied in the Fanhões-Trancão test site (north of Lisbon, Portugal) where 100 shallow translational slides were mapped and integrated into a GIS database. For the landslide susceptibility assessment it is assumed that future landslides can be predicted by statistical relationships between past landslides and the spatial data set of the predisposing factors (slope angle, slope aspect, transversal slope profile, lithology, superficial deposits, geomorphology, and land use). Susceptibility is evaluated using algorithms based on statistical/probabilistic analysis (Bayesian model) over unique-condition terrain units in a raster basis. The landslide susceptibility map is prepared by sorting all pixels according to the pixel susceptibility value in descending order. In order to validate the results of the susceptibility ana- lysis, the landslide data set is divided in two parts, using a temporal criterion. The first subset is used for obtaining a prediction image and the second subset is compared with the prediction results for validation. The obtained prediction-rate curve is used for the quantitative interpretation of the initial susceptibility map. Landslides in the study area are triggered by rainfall. The integration of triggering information in hazard assessment includes (i) the definition of thresholds of rainfall (quantity-duration) responsible for past landslide events; (ii) the calculation of the relevant return periods; (iii) the assumption that the same rainfall patterns (quantity/duration) which produced slope instability in the past will produce the same effects in the future (i.e. same types of landslides and same total affected area). The landslide hazard is present as the probability of each pixel to be affected by a slope movement, and results from the coupling between the susceptibility map, the prediction-rate curve, and the return periods of critical rainfall events, on a scenario basis. Using this methodology, different hazard scenarios were assessed, corresponding to different rain paths with different return periods.

River flooding is a specific worldwide type of flooding responsible for considerable human and material losses. An extensive knowledge about flood conditioning factors and a diverse set of methodologies for flood susceptibility evaluations are available, although there is still field for improvement regarding methodologies for small-scale flood susceptibility assessment, particularly relevant in data-scarce contexts. This research applied to mainland Portugal, introduces a multicriteria methodology to assess flood susceptibility at national scale considering three flood-conditioning factors: flow accumulation, average slope angle and average relative permeability. These three factors resume other factors usually considered in literature, related to morphology and potential runoff. This work includes data from the flood conditioning factors considering the cumulative role of the entire contributive area and not only the on-site characteristics. The weight of each factor was assigned based on expert opinion and validated using available flood damages databases with >150 years of records. From the several tested flood susceptibility models, the one that best fits the historical records was chosen, which corresponds also to a more valued role of flow accumulation factor. Results provide an accurate differentiation of transboundary, regional and local rivers. The scores of stream flood susceptibility were later transformed to a single value per each of the 278 municipalities of mainland Portugal. Representing the natural susceptibility to river flooding, these results can be cross-analyzed with structural mitigation measures, spatial planning instruments, exposure and vulnerability data along the respective floodplains, in order to identify water streams that require a more detailed and concerned future intervention and an exhaustive susceptibility study at the local scale.

Understanding the processes of land use and land cover changes (LUCC) and the associated driving forces is important for achieving sustainable development. This paper presents the LUCC in Portugal at the regional level (NUTS II) from 1995 to 2010 and discusses the main driving forces and implications associated with these LUCC. The main objectives of this work are: (a) to quantify the land use and land cover (LUC) types (level I of LUC cartography) by NUT II in Portugal for the years 1995, 2007 and 2010; (b) to assess the spatio-temporal LUCC; and (c) to identify and discuss the main driving forces of LUCC and corresponding implications based on correlations and Principal Components Analysis. The results revealed large regional and temporal LUCC and further highlighted the different and sometimes opposite time trends between neighboring regions. By associating driving forces to LUCC, different influences at the regional level were observed, namely LUCC into agriculture land derived from the construction of dams (Alentejo region), or the conversion of coniferous forest into eucalypt forest (Centre region) associated with increased gross value added (GVA) and employment in industry and forestry. Temporal differentiation was also observed, particularly in the settlements that expanded between 1995 and 2007 due to the construction of large infrastructures (e.g., highways, industrial complexes, or buildings), which is reflected on employment in industry and construction and respective GVA. However, certain LUCC have implications, particularly in energy consumption, for which different behavior between regions can be highlighted in this analysis, but also on land-use sustainability.