Abstract
Land degradation and desertification processes have intensified in the semi-arid
Mediterranean during the past century, due to a combination of climatic factors and
anthropogenic influences. Because of precipitation deficits in these environments, a positive
feedback mechanism exists where vegetation patches, with relative high infiltration capacity,
act as ‘sink’ areas, while bare soil patches, with relative low infiltration capacity, function as ‘
source’ areas of erosive runoff. Hydrological
connectivity in these environments can therefore be linked to the spatial formation of these
vegetation/soil patterns. In this research, orthophotos of two semi-natural plots taken during
a 16-year period in the Guadalentin basin in Southeast Spain are used to assess the
changes in hydrological connectivity, by analyzing the binary soil/vegetation patterns with a
digital reclassification method and landscape metrics. Aside from the technical issues in the
methodology which this test-case research was designed to address, it is found that a.
landscape metrics in both plots follow the same trends b. vegetation cover in the plots has
increased c. although the surface covered by bare soil has declined, the connectivity of the
patches of bare soil that remained has increased. Therefore it is concluded that although the
plots themselves generate less runoff, the dynamic flow of runoff through the plots has
increased.