COMPARISON OF DIFFERENT METHODS TO MEASURE SOIL EROSION IN THE CENTRAL EBRO VALLEY

Fire is a natural factor of landscape evolution in Mediterranean ecosystems. Due to social and economical changes, wildfires have caused hydrological and geomorphological changes to be more pronounced, resulting in enhanced soil erosion. The study area is located in the Zuera Mountains, near the city of Zaragoza (Spain) in the Middle Ebro Valley. These mountains were affected by two wildfires in 2008 and 2009, burned around 2000 ha and 6000 ha, respectively. Middle Ebro Valley has extreme aridity, which results in a low plant cover and high soil erodibility enhanced by the fire effects. Soil infiltration is one of the properties affected by fire as a consequence of litter and vegetation removal, heating of and changes to the biological, chemical and physical soil properties. The objective was to compare two different methods -rainfall simulations and erosion plots-, to assess soil erosion after forest fires. We compared different measurements with rainfall simulators and erosion plots, applying a woodchip cover -in order to reduce the rain splash effect-, and to measure the erosion reduction. The work showed low sediment rates in both experiments covered with woodchips.