Contemporary and long-term erosion in a pristine African Savanna, Kruger National Park, Republic of South Africa

• Applicants: Privatdozent Dr. Jussi Baade; Dr. Christoph Glotzbach
• Co-Applicant: Professorin Kate Rowntree
• Subject Area: Physical Geography
• Term: from 2013 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 243097849

Sustainable soil management requires information on present day natural rates of erosion in order to develop generally accepted management goals. Unfortunately, data on rates of natural erosion from uncultivated land under current climate conditions are difficult to find. This holds especially for southern Africa, where human induced soil erosion is believed to exceed natural rates by one or two orders of magnitude, depending on the methodological approach. Here, we propose to establish and compare contemporary and long-term natural erosion rates for an African savanna environment by investigating long-term denudation, contemporary sediment yield and sediment sources in a nature conservation area, i.e. the Kruger National Park (KNP). The KNP, located in the dry Lowveld savanna in the NE part of the Republic of South Africa is particularly suited for this study because the area was set aside for wild life conservation over 100 years ago and never experienced agricultural development. Furthermore, KNP is an exceptionally well documented area and SANParks Scientific Services at Skukuza provides full access to its data base, including a number of data sets relevant to this study on erosion (e.g., DEMs, geology, soils, vegetation and vegetation change, fire records, precipitation, drainage, aerial photos).Taking into account variation in endogenetic (geology, soils and relief) and exogenetic (climate and vegetation) drivers of erosion the objectives of this joint research project are:1) The determination of contemporary average near-natural sediment yield rates on the catchment scale based on volumetric mapping and assessment of the sediment deposited in reservoirs established 40 to 80 years ago. 2) The determination of the late Quaternary rates of erosion in this rather low relief savanna environment using cosmogenic nuclides and a comparison with the contemporary erosion rates. 3) The identification and quantification of major sediment sources within the catchments using sediment finger printing methods in order to apportion sediment yield to contributing areas of the catchment. The anticipated results will advance the understanding of the late Quaternary geomorphodynamic evolution and trajectories of savanna environments. They will provide valuable data for an assessment of the soil preservation ecosystem services of a nature conservation area when compared to the abundant data on soil erosion from cultivated land. In addition, the results are of importance for the foundation and justification of soil and water management goals in the dry savanna regions of South Africa and neighboring countries by providing contemporary and long-term natural erosion baseline rates.

• DFG Programme: Research Grants
• International Connection: South Africa