Effect of spatial scale on suspended sediment concentration in flood season in hilly loess region on the Loess Plateau in China

Fang, Huan; Chen, Hao; Qiangguo, Cai; Huang, Xin

doi:10.1007/s00254-007-0908-2

Cited by 7 publications

(1 citation statement)

References 38 publications

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“…Temporarily stored sediment is thought to be mobilized very quickly during the first stages of a storm event (Eder et al, 2010). Fast response systems of short duration and low mass magnitude, as those observed in the NF catchment, are characterized by rapid sediment flushing and fast depletion of sediment supply (Chappell et al, 1999), due to limited availability of eroded material from the protected surface (De Girolamo et al, 2015; Fan et al, 2012; Fang et al, 2008). The paved drain network in the TTP catchment can act as conduits transporting sediment instantaneously from nearby logged plantations or tracks to the stream.…”

Section: Discussionmentioning

confidence: 99%

Tropical Montane Forest Conversion Is a Critical Driver for Sediment Supply in East African Catchments

Kroese

Jacobs

Tych

et al. 2020

Water Resources Research

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Land use change is known to affect suspended sediment fluxes in headwater catchments. There is however limited empirical evidence of the magnitude of these effects for montane catchments in East Africa. We collected a unique 4-year high-frequency data set and assessed seasonal sediment variation, water pathways, and sediment response to hydrology in three catchments under contrasting land use in the Mau Forest Complex, Kenya's largest tropical montane forest. Annual suspended sediment yield was significantly higher in a smallholder agriculture-dominated catchment (131.5 ± 90.6 t km −2 yr −1) than in a tea-tree plantation catchment (42.0 ± 21.0 t km −2 yr −1) and a natural forest catchment (21.5 ± 11.1 t km −2 yr −1) (p < 0.05). Transfer function models showed that in the natural forest and the tea-tree plantations subsurface flow pathways delivered water to the stream, while in the smallholder agriculture shallow subsurface and surface runoff were dominant. There was a delayed sediment response to rainfall for the smallholder agriculture and the tea-tree plantations. A slow depletion in sediment supply suggests that the wider catchment area supplies sediment, especially in the catchment dominated by smallholder farming. In contrast, a fast sediment response and depletion in sediment supply in the natural forest suggests a dominance of temporarily stored and nearby sediment sources. This study shows that the vegetation cover of a forest ecosystem is very effective in conserving soil, whereas catchments with more bare soil and poor soil conservation practices generated six times more suspended sediment yield. Catchment connectivity through unpaved tracks is thought to be the main explanation for the difference in sediment yield.

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