Fluvial and slope-wash erosion of soil-mantled landscapes: Detachment- or transport-limited?

摘要: Many numerical landform evolution models assume that soil erosion by flowing water is either purely detachment-limited (i.e. rate related to the shear stress, power, or velocity of flow) transport-limited erosion/deposition divergence velocity). This paper reviews available data on relative importance versus soil-mantled hillslopes and low-order valleys. Field measurements indicate fluvial slope-wash modification landscapes best represented a combination conditions with each approximately equal ratio sand rock fragments silt clay in eroding soil. Available also detachment/entrainment thresholds are highly variable space time many landscapes, local threshold values dependent vegetation cover, rock-fragment armoring, surface roughness, texture cohesion. heterogeneity significant for determining form fluvial/slope-wash transport law because spatial and/or temporal variations can effectively increase nonlinearity relationship between sediment stream power. Results from modeling suggest that, aside presence distributary channel networks autogenic cut-and-fill cycles non-steady-state it difficult infer using topography alone. Copyright © 2011 John Wiley & Sons, Ltd.