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Investigating erosion and sediment transport from headwaters to catchments to reduce reservoir siltation in drylands

AXEL BRONSTERT¹, RAMON J. BATALLA², JOSÉ C. DE ARAÚJO³, TILL FRANCKE¹, ANDREAS GÜNTNER⁴, GEORGE MAMEDE^1,3 & EVA MÜLLER¹

1 Univ. of Potsdam, Dept for Geoecology, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam-Golm, Germany

axel.bronstert@uni-potsdam.de

2 Forestry and Technology Center of Catalonia & Univ. of Lleida, Dept. Env. and Soil Sci., E-25198 Lleida, Spain

3 Univ. Federal do Ceará, Dept of Agricultural Engng, Campus do Pici, bloco 804, Fortaleza, Ceará, Brazil

4 GeoForschungsZentrum Potsdam, Section Engineering Hydrology, Telegrafenberg, D-14473 Potsdam, Germany

Abstract Deposition in reservoirs threatens their reliability for water supply in dryland regions. We present a modelling scheme for the quantitative assessment of sediment mobilisation in catchments, transport in the river system, and retention in reservoirs, with a focus on meso-scale semi-arid catchments. An existing hydrological model tailored for specific semi-arid features is extended to represent erosion and sediment transport. Data sets from dryland catchments, rivers, and reservoirs in northeast Spain and northeast Brazil are used and expanded by own measurements. The first results concerning a representation of erosion-prone landscape units, the role of sediment transport in the river system, and the sedimentation in reservoirs are presented.

Key words Brazil; dryland; erosion; reservoir sedimentation; sediment transport; Spain