Modelling deep-seated slope failures in semi-arid southern Spain

Abstract

The aim of this research was to investigate the possible scenarios of occurrence of deep-seated failures under semi-arid Mediterranean and mountainous conditions, triggered by water-table shifts caused by changes in the precipitation regimen in an area of Andalucía, Spain. The methodology involved the combination of three different models calibrated with field data. The models were applied in a cascade analysis. The input of the soil water budget model was provided by rainfall, supplying the upper boundary for the seepage model, which was then used for conventional slope stability analysis. Modelling results indicated that large water-table and pressure head fluctuations would occur and affect slope stability when percolation rates reach 20% of the mean rainfall value. These conditions could be the result of the presence of extreme events, a change in the climate regime or the removal of the vegetation cover.