Sediment Yield Deduction from Check–dams Deposition in the Weathered Sandstone Watershed on the North Loess Plateau, China

Abstract

As the basic unit of erosion and sediment yield, it was critical to determine the amount of soil erosion and sediment yield in the small watersheds for sustaining a reasonable water resource and sediment regulation system. In this study, we determined the sediment yield from the dams‐controlled watershed on the North Loess Plateau. Three check dams in the watershed were investigated by drilling ten‐hole sedimentation cores. The corresponding flood couplets were dated according to thickness of deposition layers, distribution of sediment particle size and historical erosive rainfall events. On the basis of the check dams capacity curve, the soil bulk density and the thickness of couplets, the deposit mass of check dams, and then the sediment yield of watershed at different temporal and spatial scale were deducted. In total of the 33, 60 and 55 couplets were corresponded to individual flood events in the dam MH1# from 1976 to 1984, the dam MH2# from 1985 to 2007, and the dam MH4# from 1981 to 2009, respectively. The specific sediment yield for flood events was 1,188.5–11,527.9 Mg km−2, 1,278.6–17,136.7 Mg km−2, and 3,395.9–33,698.5 Mg km−2, and the annual average sediment yield was 10,728.6 Mg (km2 · a)−1, 12,662.9 Mg (km2 · a)−1, and 16,753.3 Mg (km2 · a)−1 in dam MH1#, MH2# and MH4# controlled watershed, respectively. The sediment yields were inversely proportional to the dams – controlled areas. For the whole watershed, the annual average sediment yield was 14,011.1 Mg (km2 · a)−1 from 1976 to 2009. There were large amounts of sediments (42.3–50.5%) were intercepted gradually along the way from small watersheds to the river channel. And the minimum rainfall for sediment deposited in the dams was greater than 20 mm in this watershed. The results of this study suggested that the sediments retained behind check dams were helpful to quantifying the amount of erosion sediment yield and understanding the soil erosion evolution in the small and ungauged watersheds. Copyright © 2016 John Wiley & Sons, Ltd.

Final Analysis of the Accuracy and Precision of Methods to Calculate the Sediment Retained by Check Dams

“…Thus, a quality evaluation of these structures is needed to achieve more efficient use of resources with more sustainable results (Quiñonero et al, 2016), as they need to be placed in the best catchment location (Mekonnen et al, 2015) to exploit their full trap efficiency. For a better understanding of the role of check dams in trapping sediment, or to quantify the amount of sediment yield in their basins (Wei et al, 2016), retained sediment should be then measured using the most accurate methods. Given that a sound calculation of the volume depends on the accuracy of the topographic survey and the chosen method (Verstraeten & Poesen, 2002), the importance of the method and methodology employed are essential.…”

Topographic Spatial Variation Analysis of Loess Shoulder Lines in the Loess Plateau of China Based on MF-DFA

“…The Suide site is characterized by a large number of artificial terraces of various types, which have a great effect on reducing the soil erosion [68]. In addition, the site also has a large number of check-dams, which also has a great effect on weakening soil erosion [69][70][71]. The check-dam intercepts a large amount of sediment from an upstream channel, and the slope in combination with the siltation of the check-dam, gradually forms a new equilibrium profile upstream, and elevates the erosion datum of its control site.…”

Variation in the sediment deposition behind check‐dams under different soil erosion conditions on the Loess Plateau, China

“…The soil types are characterized by weathering sandstone, loess, and desert sand, and the land surface is dominated by dense gullies with poor vegetation cover (Wang et al ., ). In China, weathering sandstone (locally called pisha sandstone) is a general appellation for some types of fluvial clastic deposition sandstones and specifically refers to an interbedded rock consisting of Paleozoic Permian (approximately 2.5 hundred million years), Mesozoic Triassic, Jurassic and Cretaceous thick sandstone, sand shale and argillaceous sandstone (Ni et al ., ; Wei et al ., ). Although the area of pisha sandstone only accounts for 2.6% of the total Loess Plateau area, its coarse sediment yield accounts for 30% of the total coarse sediment in the upper–middle reaches of the Yellow River (Yang et al ., ).…”

“…Finally, the sediment deposition rate and sediment deposition yield were obtained from the sediment deposition thickness and the mass of the couplets divided by its controlled watershed area, respectively. More details of these methods were described in Wei et al (2017).…”