Instabilidade em terraços agrícolas no Vale do Douro, Pinhão : modelação matemática de base física

Abstract

To evaluate the landslide susceptibility of on agricultural terraces with risers and stone wall support structures in the Douro Region, physically based mathematical models were applied. Were used the SHALSTAB and SINMAP models, which combine an infinite slope stability analysis model and a steady state hydrological model. Both use the following basic physical parameters: cohesion, friction angle, specific weight and soil thickness.Besides the different mathematical formula used in each model, the modelling of the hydrological model contributory areas is based on different algorithms. The validation of the modelling results was made using the inventory of past landslides and applied the contingency matrix method. According to the results, the SHALSTAB classifies 77% of the landslides on the high susceptibility areas, while SINMAP only classifies 51%.