SP3: Long-term erosion processes

For a qualified assessment of the climate-anthropogenically caused land degradation, natural long-term estimates of denudation are required, which will be quantified in this subproject.

The aim of this subproject is to determine the long-term natural denudation over thousands of years with the help of cosmogenic nuclides. These can then be compared with short-term measurements (SP 1.2) to determine the anthropogenic contribution to land degradation.

We will use cosmogenic nuclides (10Be) to determine long-term denudation in all study areas. Instead of local samples we will take river sediment samples to estimate average denudation rates for whole catchment areas. The same catchment areas as in SP1.2 are preferred.

On the German side we work very closely together with SP1.2 and on the South African side with iThemba Laboratory, which will measure the samples.

We will determine natural long-term erosion rates from selected catchments and then compare them with the short-term erosion rates from remote sensing, reservoir sediments and soil erosion modelling determined in sub-project SP1.2. The comparison of the erosion rates averaged over different time scales will show the extent of the climatic anthropogenic influence on recent land degradation in South Africa.