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DOI	10.1016/j.quascirev.2024.108654
	Evolution of the alluvial fan channel longitudinal profile and aggradation/ degradation processes in the piedmont
	Zhang, Yanan; Hu, Xiaofei; Wang, Wei; Pan, Baotian
发表日期	2024
ISSN	0277-3791
EISSN	1873-457X
起始页码	331
卷号	331
英文摘要	In the piedmont of uplifting mountains, alluvial fan rivers undergo significant aggradation-degradation processes, which are usually attributed to climate change. An ongoing debate is whether this process requests the participation of glaciation. To address this debate, we need the knowledge of the quantitative relationship between the ratio of water to sediment flux (q(w)/q(s)) with the aggradation/degradation process. This study examined the aggradation and degradation processes in three alluvial rivers at the piedmont of the Qilian Shan (Shan referes to Mountain) and simulated the river processes by a one-dimensional numerical model based on the transport-limited principle. Along the studied piedmont rivers, field measurements show a magnitude of 120-200 m degradation and aggradation in the Late Pleistocene. Through simulation analysis, we explored how factors like the ratio of water to sediment flux (q(w)/q(s)), channel width, and sediment grain size influence river processes and longitudinal profiles, and found distinct morphologies in different processes, where aggradation is characterized by concave-up profiles, while degradation is characterized by convex-down profiles. Additionally, the water flux is inversely proportional to the time required for the river to reach a new equilibrium profile. The simulated degradation amplitude aligns closely with the measured data in the Qilian Shan, indicating that precipitation during the Last Glacial Maximum in the region amounted to approximately similar to 32% of the Holocene precipitation. This supports the notion that changes in water flux or precipitation alone can induce significant piedmont deepening without the necessity of glaciation.
英文关键词	Qilian Shan; Channel longitudinal profile; Numerical simulation; The ratio of water to sediment flux; Channel width; Sediment grain size; Quaternary; Paleoclimatology; China; Geomorphology
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:001230050700001
来源期刊	QUATERNARY SCIENCE REVIEWS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/309965
作者单位	Lanzhou University
推荐引用方式 GB/T 7714	Zhang, Yanan,Hu, Xiaofei,Wang, Wei,et al. Evolution of the alluvial fan channel longitudinal profile and aggradation/ degradation processes in the piedmont[J],2024,331.
APA	Zhang, Yanan,Hu, Xiaofei,Wang, Wei,&Pan, Baotian.(2024).Evolution of the alluvial fan channel longitudinal profile and aggradation/ degradation processes in the piedmont.QUATERNARY SCIENCE REVIEWS,331.
MLA	Zhang, Yanan,et al."Evolution of the alluvial fan channel longitudinal profile and aggradation/ degradation processes in the piedmont".QUATERNARY SCIENCE REVIEWS 331(2024).