The use of Easy-Barriers to control soil and water losses in fire-affected land in Quesada, Andalusia, Spain

摘要

Soil erosion is enhanced by wildfire, mainly due to the loss of vegetation cover and changes in soil properties. After wildfires, there is a need to control the non-sustainable soil and water losses. Of the strategies commonly applied, the use of contour felled log debris barriers to sediment trapping is widespread, but this is not always successful in Mediterranean Ecosystems. This paper evaluates the effectiveness of a new barrier which can be applied on steep terrains affected by wildfires. The hydrological response and sediment delivery were measured to test a innovative design, which are easy to transport and use. The Easy-Barriers (EB) size is 0.8 x 0.1 x 0.2 m and were designed to restore degraded areas which need a quick, low-cost solution, such as after a wildfire. The experimental design was based on the analysis of a simulated runoff flow of 0.6 l. s(-1) circulated on 6 plots of 24 m(2) (0.8 x 30 m), on each of which 2 treatments were systematically applied: Control and EB. The EB were set up after the assessment of the runoff generation and the site rainfall characteristics for "extraordinary" events. We measured the rills, the sediments collected on each slope and the topographical changes. The total load and runoff in the outlet of the plots were also quantified using sediment volume and concentration measurements. The EB resulted in a decrease in the peak flow and a delay in the runoff time at the outlet. The sediment trapping rate of the barriers was 42.7%. The soil moisture was higher in the EB plots due to the accumulated sediment. these features, the EB allow us to save between 30 and 40% of total restoration costs in comparison with traditional barriers, due to the reduction in labour costs. Moreover, all its components are biodegradable. (C) 2019 Published by Elsevier B.V.