Mass movements are important geomorphic agents in the Inferninho river basin. Studies carried out in the area showed that hillslope hydrology plays a major role in that movements. Therefore, this study aims to characterize the hydrological dynamic in the hills of the basin.

Toposequences were investigated in a slope limited by the alluvial plain, with height of 50m and with landslide scars. Precipitation, gravimetric moisture and piezometric levels were monitored during one year in this slope.

The material in situ along the studied hill forms a vertical succession of horizons following the topography, with lateral variations at the base originated by the water table. Heterogeneous colluvium appears inside the scars and sandy alluvium occurs at the base of the slope. Yellow levels with saturation indication are developed in the materials of the scar, coinciding with the position of the piezometric levels during intensive rainfalls. Also, yellow levels appear in the top of the slope, where they seem to be a stage of shut depressions development. Geophysical investigations accomplished in the area show that the weathered bedrock is deeper at the top of the hillslope than at its base.

An alignment with accumulation of iron is found below the large scar, at the contact of the sandy alluvial package with the weathered bedrock, indicating an old path of preferential flow. Today, subsurface flow converges to an alignment inside the large scar where the topography is divergent at the surface. This occurs because of the existence of colluvial materials with high values of hydraulic conductivity. In another alignment, the concave form of the slope maintains the water table in high total potentials.

The exfiltration of subsurface flow at the footslope expands the scar, generating a channel head with permanent flow. Saturation overland flow was observed in very humid periods in the contact between the hillslope and the plain.