Cambios geomorfológicos en cauces torrenciales en relación con cambios en la cubierta vegetal

Abstract

The Ijuez River drains a small catchment in the Eocene flysch of the Central Pyrenees, with natural and reforested forests and subalpine grasslands above 1700 m. The alluvial plain shows the typical characteristics of braided rivers, with a large accumulation of coarse sediment and a wandering channel. A reach of 4 km has been studied in detail, where the presence of several sedimentary structures reveals the occurrence of various hydrological and geomorphic changes: (i) a fluvial terrace located 3-4 m above the actual channel; (ii) a large debris flow accumulation over the terrace; and (iii) the alluvial plain, which has recently incised into de sediment accumulation. These structures are inferred to be the consequence of land cover changes occurred in the subalpine and montane belts in the last 150 years.