Investigation of relationships between measured field indicators and erosion processes on badland surfaces at Petrer, Spain

Indicators were obtained to measure and predict rill erosion and mass wasti ng in biancana and calanchi-like badland areas. Rainfall simulation experim ents were used to find a relationship between soil moisture change and sedi ment concentration behaviour. This relationship appeared to be able to show , in its role as indicator, differences between materials affected by vario us degrees of rill erosion or mass wasting. Indicators explaining this rela tionship are surface characteristics, runoff and infiltration characteristi cs and chemical and mineralogical soil properties. From the experimental st udy it was concluded that the high infiltration capacity in materials affec ted by mass wasting resulted in an unstable soil and a high degree of erodi bility. The materials which were more affected by rill erosion or had a con tinuous crust at the surface were saturated earlier during the experiment t han the other materials. This saturation caused an increase in runoff. The mechanism is explained as the system crossing a threshold after which flow hydraulics at the surface are more important fur erosion processes than dyn amic soil properties and infiltration characteristics. (C) 2000 Elsevier Sc ience B.V. All rights reserved.