Integrated analysis of sediment source areas in an Alpine basin

CATENA ◽  
2020 ◽  
Vol 188 ◽  
pp. 104416 ◽  
Author(s):  
D. Oss Cazzador ◽  
R. Rainato ◽  
M. Cavalli ◽  
M.A. Lenzi ◽  
L. Picco
2017 ◽  
Vol 42 ◽  
pp. 10-13 ◽  
Author(s):  
Caterina Ferrato ◽  
Jessica De Marco ◽  
Paolo Tarolli ◽  
Marco Cavalli
Keyword(s):  

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 39 ◽  
Author(s):  
Lifeng Yuan ◽  
Kenneth J. Forshay

Soil erosion and lake sediment loading are primary concerns of watershed managers around the world. In the Xinjiang River Basin of China, severe soil erosion occurs primarily during monsoon periods, resulting in sediment flow into Poyang Lake and subsequently causing lake water quality deterioration. Here, we identified high-risk soil erosion areas and conditions that drive sediment yield in a watershed system with limited available data to guide localized soil erosion control measures intended to support reduced sediment load into Poyang Lake. We used the Soil and Water Assessment Tool (SWAT) model to simulate monthly and annual sediment yield based on a calibrated SWAT streamflow model, identified where sediment originated, and determined what geographic factors drove the loading within the watershed. We applied monthly and daily streamflow discharge (1985–2009) and monthly suspended sediment load data (1985–2001) to Meigang station to conduct parameter sensitivity analysis, calibration, validation, and uncertainty analysis of the model. The coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE), percent bias (PBIAS), and RMSE -observation’s standard deviation ratio (RSR) values of the monthly sediment load were 0.63, 0.62, 3.8%, and 0.61 during calibration, respectively. Spatially, the annual sediment yield rate ranged from 3 ton ha−1year−1 on riparian lowlands of the Xinjiang main channel to 33 ton ha−1year−1 on mountain highlands, with a basin-wide mean of 19 ton ha−1year−1. The study showed that 99.9% of the total land area suffered soil loss (greater than 5 ton ha−1year−1). More sediment originated from the southern mountain highlands than from the northern mountain highlands of the Xinjiang river channel. These results suggest that specific land use types and geographic conditions can be identified as hotspots of sediment source with relatively scarce data; in this case, orchards, barren lands, and mountain highlands with slopes greater than 25° were the primary sediment source areas. This study developed a reliable, physically-based streamflow model and illustrates critical source areas and conditions that influence sediment yield.


2002 ◽  
Vol 24 (1) ◽  
pp. 53-118

The following chapter is intended to provide a comprehensive field description of the Torridonian, replacing that given in the Geological Survey's NW Highlands memoir of 1907, and citing all relevant literature. Stratotypes and palaeocurrents are described, along with the section lines used to construct the regional stratigraphic sections (Figs 4&23), but detailed consideration of topics such as geochemistry, diagenesis, sediment source areas, palaeomagnetism and basin tectonics is contained in Chapters 2-5. for convenience the rocks are described under thirty-three compact subareas, most of which are shown on Plate 2. This plate also locates all figured maps and sections. The Directory starts with Cape Wrath and continues with sub-areas progressively farther south.The Geological Survey divided the Cape Wrath succession into three stratigraphic units, without definitely correlating any of them with the formations of the Torridon Group that they had established farther south (Peach et al. 1907, p. 292). They described the lowest unit (30 m thick) as coarse pebbly sandstone or basal conglomerate; the middle unit (300m thick) as coarse red sandstone with pebble bands, and the uppermost unit (75 m thick) as finegrained mottled purple and yellow sandstones.Remapping by Williams (1966a, 1969a, 2001) enabled him to subdivide the sequence stratigraphically into five main lithological units, which he called facies associations (FA) even though they always appear in the same order (cf. the definition of facies given on p. 2). Each successive facies is finer than the one below, as shown by the representative logs in Figure


2021 ◽  
Author(s):  
Haiyan Fang

Abstract As the only water drinking resource in Beijing, the Miyun Reservoir is still suffered over ten thousand tons of sediment input from its upper catchment. Explicating sediment sources of the catchment upstream of the reservoir is urgently required to further implement soil conservation measures. In this paper, the Revised Universal Soil Loss Equation (RUSLE) and Sediment Delivery (SEDD) models were combined to explicate the major sediment source of the catchment through exploring the spatial distributions of soil erosion and sediment delivery as well as their relations with land use and topography, and sediment source areas were then identified. The catchment average soil erosion intensity (SEI) of 4.08 t ha− 1 yr− 1 was two times the soil loss tolerance (T = 2.00 t ha− 1 yr− 1) of the study region. The values of cell sediment delivery ratio (SDR) showed a network distribution pattern, ranging from zero to unit, with an average of 1.65%. Cell specific sediment yield (SSY) presented a similar spatial pattern to SDR, ranging from 0 to 902 t ha− 1 yr− 1, with an average of 0.04 t ha− 1 yr− 1. Bare land suffered the highest SEI of 39.01 t ha− 1 yr− 1, followed by shrub land and orchard field. Nearly 70% of the sediment came from grass land. Farmland was the second sediment contributor. Grass land and farmland are the two major sediment source areas. Soil conservation practices should be further implemented on these lands, especially on the 3–5°slopes with elevations less than 500 m a.s.l.


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