Controls on a scale explicit analysis of sheet erosion

摘要: Although the impact of sheet erosion on evolution soils, soil properties and associated ecosystem services across landscapes is undisputed, there are still large uncertainties in estimation erosion, as results obtained highly scale dependent. Consequently, a need to develop scale-explicit understanding sediment yields, from microplot hillslope through plot, surmount actual modelling flaws improve guidance for mitigation. The main objective this study was compare yields small plots installed under different environmental conditions interpret these terms mechanisms controlling factors erosion. Fifteen 1 × 1 m² ten 2 × 5 m² were foothills Drakensberg, South Africa. Data runoff, concentration (SC), loss (SL) rainfall characteristics during 2009–2010 rainy season at two spatial scales vegetation cover, geology topographic used identify Scale ratios SC SL subsequently calculated assess level contribution rain-impacted flow (RIF) overall average runoff rate (n = 17 events) ranged between 4.9 ± 0.4 L m-2 1 m2 5.4 ± 0.6 L m2 10 m2, which did not correspond significant differences P < 0.05 level. Sediment losses significantly higher 10 m2 plots, compared with (2.2 ± 0.4 vs 1.5 ± 0.2 g L-1 SC; 9.8 ± 1.8 3.2 ± 0.3 g m-2 SL), illustrated greater efficiency longer slopes. Results principal component analysis, whose first axes explained 60% data variance, suggested that mainly controlled by (rainfall intensity amount) surface features (crusting coverage). RIF lowest high clay content (r = 0.26) highest crusting bulk density (r = 0.22), cumulative amount rise water table (r = 0.29). Such an explicit consideration role process domination either situ (soil conditions) or ex antecedent rainfall) factors, expected contribute process-based Copyright © 2012 John Wiley & Sons, Ltd.