Human impact on soil degradation based on cosmogenic radionuclide measurements in a semi-arid region in Southeast Spain
Description
The Mediterranean region has been populated and cultivated since thousands of years by various civilizations, and its landscape is the product of a long land use history. This research project aims to contribute to the understanding of the long-term impact of humans on erosion processes in the Western Mediterranean region. The main question that is driving this research is: ‘What is the impact of past occupation on soil erosion?’ To address this research question systematically, we are working along four lines (SE Spain, fig. 1).
Figure 1: location of the study area.
First, a compilation of environmental data at the regional scale has been performed for the Holocene time period. Past climate and vegetation have been reconstructed based on local terrestrial studies and marine sediment cores from the Alboran Sea. Changes in human occupation and sediment fluxes have been analysed based on archeological data (Archaeomedes and Aguas projects) and alluvial terraces.
Secondly, we investigated the modern erosion processes based on the volume of sediment trapped behind check dams (n = 36). Their selection has been performed in order to get a large spatial distribution (Sierra de Los Filabres, Sierra Alhamilla, Sierra de Las Estancias). In the context of soil degradation, we specified the main factors controlling those erosion rates (e.g. topography, land use, soil properties, climate).
Thirdly, long-term erosion rates for Southern Spain are quantified based on concentrations of cosmogenic radionuclides in river sediments (Be-10; Fig. 2). Given the long occupation history of this region, we will test if these long-term erosion rates truly reflect ‘natural’ or ‘geological’ erosion processes.
Figure 2: Nuclide concentration and long term erosion rates.
Finally, the impact of humans on erosion will be analysed from a reconstruction of erosion rates for different time periods. Long-term erosion rates will be compared with contemporary sediment fluxes to quantify changes in erosion rates through time.
This project is funded by the Fonds de la Recherche Scientifique - FNRS.
Contacts
Current contributors
- van Wesemael Bas
- Albert Solé Benet (EEZA, Estacion Experimental de Zonas Aridas, Spain)
References
N. Bellin, B. van Wesemael, A. Meerkerk, V. Vanacker, G.G. Barbera, 2009. Abandonment of soil and water conservation structures in Mediterranean ecosystems. A case study from South-east Spain). Catena 76, 114-121.
N. Bellin, V. Vanacker, 2010. Holocene climate evolution, human occupation, soil erosion and vegetation cover change in southeast Spain. Geophysical Research Abstracts. Vol. 12, EGU2010-3986.
Files
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