Erosión y desertificación.-Determination of bare soil and its seasonal variation using image analysis

Abstract

ABSTRACT Bare soil is of outstanding interest as an indicator of land degradation because it is strongly related with water erosion, particularly in low-vegetated areas as those typical of the Mediterranean rangelands. In areas with high livestock densities, erosion can ultimately get to a partial or total soil loss, particularly at the beginning of the rainy season, when the surface cover is reduced after the dry summer period. Therefore, it is necessary to develop accurate methods allowing the quantification of soil exposed areas and their temporal dynamics. The main goal of this work is the determination of bare soil surfaces using aerial orthophotomaps and the analysis of the changes resulting from the analysis and classification of images corresponding to two contrasting seasons (summer and spring). The study area located in Monroy, C�ceres province, Spain, is a privately owned farm 1,024 hectares in size, and is grazed by sheep and pigs. It correspond to a representative area of the wooded rangelands (dehesas) characteristics of the south-western part of Iberian Peninsula