196. Temporal and Spatial Interactions of Slope and Catchment Processes in the Central Spanish Pyrenees

Historical and present day changes in land use and plant cover explain the complex interactions assessed in the Central Spanish Pyrenees between geomorphic processes in hillslopes and channels. More intense erosion periods caused and enlargement of sediment source areas and an increase of sediment supply toward the rivers, characterized by braided channels. A sharp difference existed between the human-induced eroded areas and the rest of the territory, which shows moderate erosion rates. Farmland abandonment in the last few decades has reduced the sediment sources, thus decreasing both sediment delivery and streamflow, as a consequence of plant colonization of the old fields. Fluvial channels also show a decreasing torrential activity over the 20th century.