A conceptualization of the processes influencing sediment deposit

A conceptualization of the processes influencing sediment deposition and storage

can be instructive for understanding U0126 mw this variability. The production of sediment (erosion) on a hill slope (PS) depends on landscape sensitivity, the intensity of land use, and external factors. Landscape sensitivity is governed by biogeomorphic factors, such as slope, lithology, soils, and vegetation. Land-use intensity depends on cultural and socioeconomic factors, such as population density, land-use technology, export economies, and conservation practices. Exogenetic factors include extreme meteorological events, climate change, or tectonics. The amount of sediment that is delivered to a site find more (DS)—critical to understanding where LS may be deposited and how long it will be stored—is usually substantially different than the amount of sediment produced on hill slopes due to storage or recruitment of sediment in transit ( Phillips, 2003). The proportion of sediment that is delivered is usually much less than 100% due to a dominance of deposition and storage over recruitment. This is especially

true during episodic events when accelerated erosion results in a surplus of sediment production beyond equilibrium loadings. Sediment delivery depends not only on sediment production on hill slopes, but also on conditions that govern deposition and recruitment, including transport capacity, sediment characteristics, and valley-bottom conditions. Many of these factors are scale-dependent and vary systematically with drainage area. MTMR9 Sediment characteristics that influence deliveries include grain size, shape, cementation, imbrication, and armoring. Relevant valley-bottom factors include morphology, floodplain width, position relative to channels, geologic structure, valley gradient, base-level, history of sea-level change, previous history of channel aggradation or incision, glacial history, and human alterations (channel-bed mining, dams, levees, etc.) (Belmont, 2011, Blum and Törnqvist, 2000 and Nardi et

al., 2006). Storage potential also depends on local connectivity between lateral and longitudinal linkages and blockages referred to collectively as (dis)connectivity (Fryirs, 2013). Blockages consist of buffers, barriers, and blankets that limit lateral, longitudinal, and vertical connectivity, respectively. This provides a means of identifying and tallying sites where storage may accrue and of quantifying sediment storage potential and delivery. Storage components can be classified as ‘stores;’ i.e., relatively temporary storage components, or ‘sinks;’ i.e., relatively persistent storage components ( Fryirs, 2013). Much of the sediment within channels may be considered to be stores, whereas floodplains are largely sinks.

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