Infiltration processes in the badlands of eastern Iberian peninsula : progresses and challenges

Abstract

Badlands are geomorphological miniature laboratories that contributed to the landforms and geomorphological processes studies. Infiltration is a key process in the hydrological cycle because it manages the volume of surface water and thus the erosive processes. Studying the process of infiltration into badlands gain insight on both, the process of infiltration and on badland geomorphology, and the results can be extrapolated to other areas where the high losses of soil and water must be controlled. This paper presents a review of the research regarding the infiltration in the badlands from experiments developed in the last two decades in the badlands of eastern Iberian Peninsula. The use of rainfall simulation experiments and cylinder infiltrometers measurements has provided relevant information to determine the effects of parent material, seasonality, time and geomorphological position on the process of infiltration, and then on the runoff generation and soil loss. Despite the lack of vegetation cover, and low soil development, the process of infiltration is highly complex in the badland surfaces because they generate macroporos from cracks that favor water infiltration and thus the piping developement. In the absence of vegetation, is the parent material through the surface morphology (cracks) the dominant factor in the processes of infiltration. Topographical position is key to understand the geomorphological processes in areas of badlands because the pediments behave as simple transmitters of water and sediment coming from the slopes because of its small infiltrabilidad and lack of cracks. Cracks also explain why the seasonality in the infiltration capacity of the regolith is high. Thus, the infiltration process in badlands is characterised by a highly seasonal, temporal and spatial variability which is key on the geomorphological processes behaviour.