Sediment concentrations in run-off varying with spatial scale in an agricultural subwatershed of the Chinese Loess Plateau
文献类型：SCI/SSCI论文
| 作者 | Zheng M. G.; Li, R. K.; He, J. J. |
| 发表日期 | 2015 |
| 关键词 | soil erosion sediment yield scale hyperconcentrated flows Loess Plateau hilly areas soil-erosion hyperconcentrated flow delivery problem debris flow basin area yield dependency catchment river |
| 英文摘要 | Information is scarce on the spatial-scale effect on sediment concentrations in run-off. This study addressed this issue within an agricultural subwatershed of the Chinese Loess Plateau, using data observed at a hilltop plot, three nested hillslope plots, two entire-slope plots (a combination of hillslope and valley side slope) and the subwatershed outlet. Dominated by the splash and sheet erosions, the hilltop plot has a minimum C-ae (mean sediment concentration for all recorded events) of 45 kgm(-3). Unexpectedly, the high sediment concentrations at the hilltop do not occur at high rainfall intensities or large run-off events because of the protection of surface soils by relatively thick sheet flows. Because of the emergence of rills, C-ae is as high as 310 kg m(-3) even on the most upper hillslope. Downslope, both C-ae and ESC (extreme large values of recorded sediment concentrations) increase; such a slope length effect attenuates with increasing slope length and event magnitude as a result of insufficient sediment availability associated with rill development. Active mass wastings ensure sufficient sediment supply and thus a spatially invariant C-ae (approximately 700 kgm(-3)) and ESC (approximately 1000 kg m(-3)) at the scale of the entire slope and subwatershed. Detailed examination shows that most small events experience a decrease in sediment concentrations when moving from the entire slope to the subwatershed, indicating that the spatially invariant sediment concentration is valid only for large run-off events. This study highlights the control of the spatial scale, which determines the dominant erosional process, on erosional regime. Copyright (C) 2015 John Wiley & Sons, Ltd. |
| 出处 | Hydrological Processes |
| 卷 | 29 |
| 期 | 26 |
| 页 | 5414-5423 |
| 语种 | 英语 |
| ISSN号 | 0885-6087 |
| DOI标识 | 10.1002/hyp.10576 |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/43603]  |
| 专题 | 地理科学与资源研究所_历年回溯文献 |
| 推荐引用方式 GB/T 7714 | Zheng M. G.,Li, R. K.,He, J. J.. Sediment concentrations in run-off varying with spatial scale in an agricultural subwatershed of the Chinese Loess Plateau. 2015. |
入库方式： OAI收割
来源：地理科学与资源研究所
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