Evidence from field-based studies of rates of soil erosion on degraded land in the central Karoo, South Africa

Abstract

The goal of the research is to develop components of the method aimed at output of information on reliefforming processes from archival and current remote sensing (RS) data with the use of the latest dataprocessing technologies, inclu ding photogrammetry and geoinformation systems (GIS). The proposed components of the methods are highly informative and economically effective. The object under study is located at the border of two active tectonic structures, the South Tatar arch and Melekesskian depression in the southeastern part of the East European platform (Fig. 1). Based on the study results, it is confirmed that neotectonic movements in the area under study and its recent geodynamical setting are directly related (Fig. 5). It is demonstrated that the morphometric method can be efficiently applied to predict zones of high geodynamic activity and to determine locations of such zones.

Gully morphology, hillslope erosion, and precipitation characteristics in the Appalachian Valley and Ridge province, southeastern USA

“…Recent research in South Africa's semi-arid Karoo badlands region has shown that channel erosion in colluvium behaves in a "cut-and-fill" manner in that the measured erosion is small, but the quantity of material moved through the channel is nearly an order of magnitude greater than the measured erosion because sediment is eroded and redeposited in successive events (Keay-Bright and Boardman, 2009). Moreover, within a gully system there is significant contribution of sediment from sidewalls and interfluve/interrill areas.…”

“…A few studies have investigated the relationship between precipitation intensity and soil erosion at the plot scale under natural precipitation conditions over several years (Baartman et al, 2012;Keay-Bright and Boardman, 2009;Porto et al, 2014;Wei et al, 2010). Capra et al (2009) investigated the relationship between gully erosion and the precipitation erosivity factor in a cultivated catchment in Italy at a yearly scale.…”

“…Precipitation-erosion studies using actual precipitation records on hillslopes have been conducted in regions with very different soil and climate conditions than those present in Ultisols in the humid subtropical climate of southeastern United States (Hancock and Evans, 2010;Keay-Bright and Boardman, 2009;Sirvent et al, 1997;Smith and Dragovich, 2008). Gully erosion in the southeastern United States, particularly in the Appalachian Valley and Ridge and Piedmont provinces, given the areal extent is a greatly under-researched area.…”

Long-term studies of land degradation in the Sneeuberg uplands, eastern Karoo, South Africa: A synthesis

“…They are described as lithosols (shallow soils on hard or weathered rock (SANBI, 2012). This is particularly true of badlands and heavily degraded areas where surfaces are compact: bulk densities 1.6-1.9 g cm 3 with mean organic matter content of 2.4% (Keay-Bright and Boardman, 2009;Dickie and Parsons, 2012). Mean particle size for 10 badland sites (< 2mm) is reported as 7% clay, 66% silt and 27% sand using a Malvern laser-granulometer with Hydro-2000 dispersal unit .…”

Soil Erosion Rates in South Africa Compared With Cosmogenic 3he-Based Rates of Soil Production

“…However, most material eroded by humans is not delivered to the oceans, but is deposited within catchments if the carrying capacity of rivers is exceeded. Thus, local soil erosion rates may be an order of magnitude greater than the net sediment yield to the oceans (Martin, 1987;Garland et al, 1999;Wilkinson and McElroy, 2007;Keay-Bright and Boardman, 2009). …”