Dube H. B., Mutema M., Muchaonyerwa P., Poesen J., Chaplot Vincent. (2020). A global analysis of the morphology of linear erosion features. Catena, 190, p. art. 104542 [12p.]. ISSN 0341-8162.
Titre du document
A global analysis of the morphology of linear erosion features
Dube H. B., Mutema M., Muchaonyerwa P., Poesen J., Chaplot Vincent
Source
Catena, 2020,
190, p. art. 104542 [12p.] ISSN 0341-8162
Concentrated flow erosion poses a serious threat to agriculture across the world as it scours soils into linear features that can be wide and large, which dramatically decreases land productivity and accessibility, and causes serious downslope and downstream impacts. Despite the widespread occurrence of concentrated flow erosion features across the globe, variations in their sizes have received limited attention. Their morphometric characteristics inform on the amount of fertile soil material eroded and transported to lower parts of landscapes and to river networks. The main objective of this study was to elucidate the impacts of climate (tropical, sub-tropical and temperate), soil texture (clayey, loamy, silty and sandy) and land use (cropland, forest, grassland and urban) on the morphology (length: L, width: W, depth: D, W:D ratio) of linear erosion features (rills and gullies). A total of 769 linear features from 53 published studies across the world were used in the current analysis. The average length was 458.2 m for gullies and 114.7 m for rills. Width averaged 9.5 m for gullies and 1.0 m for rills and W:D was respectively 4.0 and 6.7, which corresponded in all cases to significant difference at P < 0.05. Oceania exhibited the longest (1201 m on average) but shallowest (0.88 m) gullies. Asia had the widest (21.9 m) and Africa the deepest (6.3 m) gullies. In contrast, Europe exhibited shorter gullies (304 m) and rills (56 m) and of low width (5.0 and 0.6 m respectively). Besides, there was a trend for rills to decrease in L, W and D with the increase in mean annual precipitation and for rills' W to increase with increasing mean annual temperature (r = 0.32). The length of the features also increased from forest to settlement through grassland and cropland, and with increasing altitude above sea level (r = 0.47 for gullies and r = 0.26 for rills). As soil clay content increased, the depth of rills increased (r = 0.19) and their W:D decreased (r = - 0.14). These quantitative results may contribute to erosion modelling and to the spatial assessment of land susceptibility to concentrated flow erosion, which is a prerequisite for the protection and rehabilitation of ecosystems.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Pédologie [068]
