Verbundprojekt SPACES2: Südafrika Landdegradationsmonitor (SALDi) - Teilprojekt 3: Langfristige Erosionsprozesse

26/09/2018 to 25/09/2021

Within this subproject, estimates of natural long-term erosion rates are determined. For this purpose,
averaged long-term erosion rates are quantified by measurements of cosmogenic nuclide
concentration of river sediments in selected regions in South Africa. Based on the high penetration
depth of cosmic radiation into the ground (a few meters) and the low long-term erosion rates (~ 5 mm
/ ka) in this region, the measured nuclide concentrations reflect the development of the earth's
surface over the last approx. 100 ka. Small-scale and/or short-term changes in the earth's surface,
eg. changes in agricultural use in recent decades or climate change do not affect the measured
nuclide concentrations. The erosion rates determined from the nuclide concentrations thus
correspond to the pre-anthropogenic natural background and can be compared with estimates of
anthropogenically-influenced erosion. Assuming that new soil formation rates roughly correspond to
long-term erosion rates, a negative balance (short-term erosion exceeds long-term erosion) indicates
effective soil erosion. The project requested here provides important estimates for a sustainable soil
management system in South Africa in the SALDi joint project (South Africa Land degradation
monitor) and is part of the BMBF funding program "Research Partnerships for the Evaluation of
Complex Processes in the Earth System in the Southern Africa - SPACES" region. Framework
Program "Research for Sustainable Development" (FONA). SALDi will use innovative methods to
improve land degradation monitoring in South Africa.