Stream networks and knickpoints in the Sanjiangyuan Region

Annals of Warsaw University of Life Sciences – SGGW
Land Reclamation No 42 (1), 2010: 79–91
(Ann. Warsaw Univ. of Life Sci. – SGGW, Land Reclam. 42 (1), 2010)

Stream networks and knickpoints in the Sanjiangyuan Region

ZHAOYIN WANG1, GUO-AN YU2, GARY BRIERLEY3, LE LIU4
1State Key Laboratory of Hydroscience and Engineering, Tsinghua University, China
2Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences
3School of Environment, University of Auckland
4Department of Hydraulic Engineering, Tsinghua University, China

Abstract: The source area of the Lancang (Mekong), Yangtze and Yellow rivers is named in Chinese Sanjiangyuan (source of three rivers). Geographical characteristics of these rivers, and various rivers at the margin of the Qinghai-Tibetan Plateau (Jialing, Minjiang, Dadu, Yalong and Jinsha) are summarized from field investigations along with digital elevation model (DEM) analyses and satellite images. Uplift of the Qinghai-Tibetan Plateau has resulted in an asymmetrical distribution of tributaries for stream networks at the margins of the plateau. Almost all tributaries join the trunk stream from the northwest. Three types of drainage network are evident: plume, nervation and dendritic. In general, plume networks have a large number of first order streams. Nervation networks have a main stream and parallel tributaries. Dentritic networks are characrterized by continuous bifurcation and have a branch-like appearance. Most stream networks in the Sanjiangyuan region are of the nervation type. Several large knickpoints are evident along the longitudinal profiles of the Yellow and Yangtze Rivers. Channel aggradation immediately upstream of these knickpoints marks a transition in river processes from vertical bed evolution (i.e. incision) to horizontal channel adjustment (and associated braided and anabranching channels).

Key words: Qinghai-Tibetan Plateau, knickpoint, drainage network, Sanjiangyuan, step-pool

Streszczenie: Rozwój progów skalnych oraz morfologia rzek w regione Sanjiangyuan. W artykule przedstawiono proces rozwoju progów skalnych wzdłuż rzek Yellow i Yangtze. Wykazano wpływ progów skalnych na zmiany morfologiczne dna koryt rzek. Głównie skoncentrowano się na zmianach agradacyjnych powyżej omawianych progów. Progi te są wyznacznikami zmian charakteru koryta rzecznego, z pionowo wciętego na wielonurtowy, roztopowy o szerszym korycie. Badania wykonano w rejonie Qinghai_Tibetan Plateau, zwanym obszarem źródłowym trzech rzek – oprócz wyżej wspomnianych również rzeka Mekong.

Please use the following format to cite the selected article:
ZHAOYIN WANG, GUO-AN YU, GARY BRIERLEY, LE LIU. Stream networks and knickpoints in the Sanjiangyuan Region. Annals of Warsaw University of Life Sciences – SGGW. Land Reclamation No 42 (1), 2010: 79–91

Authors’ addresses:
Zhaoyin Wang
State Key Laboratory of Hydroscience and Engineering, Tsinghua University,
Beijing 100084, China

Guo-An Yu
Institute of Geographical Sciences and Natural Resources Research
Chinese Academy of Sciences
Beijing 100101, China

Gary Brierley
School of Environment, University of Auckland

Le Liu
Department of Hydraulic Engineering
Tsinghua University
Beijing 100084, China
e-mail: zywang@tsinghua.edu.cn

ZHAOYIN WANG, GUO-AN YU, GARY BRIERLEY, LE LIU. Stream networks and knickpoints in the Sanjiangyuan Region

DOI 10.2478/v10060-008-0067-5