青藏高原河流演变研究进展

Progress in studies on river morphodynamics in Qinghai-Tibet Plateau

青藏高原是中国及亚洲大河的发源地,高原内部河网水系发达。在高原抬升、气候变化和人类活动的三重叠加作用下高原河流未来可能发生显著变化,由此引发的一系列交叉学科问题正成为关注热点。在前期多年高原河流野外调查的基础上,对近几十年青藏高原河流演变的研究进展,如地质背景、高原抬升和河流地貌特征与演变等进行较系统的分析和总结。展望了中等时间尺度下气候变化对河流演变的影响,短时间尺度下人类活动的局部、突变和加速的作用;提出冲积河群的新概念,初步给出其定义、特征和分布,以期在这个新框架下促进复杂辫状河道和弯曲河道形成与演变的深入研究。

The Qinghai-Tibet Plateau is the source zone of China and Asian＇s large rivers,where river network well developed within the plateau. Under the superimposed impacts of plateau uplift,climate change,and human activities,the rivers may be significantly changed in the future,resulting in a series of interdisciplinary issues which are becoming a hot topic. Following our field investigations of the plateau rivers during 2007—2016,we comprehensively summarized the research progress of river morphodynamics in recent decades,such as the related geological background,the influences of the uplift,river morphological characteristics,and fluvial processes. Furthermore,we focus on effects of climate change on river morphodynamics in the middle time scale,and the local,abrupt and accelerating effects of human activities on the short time scale. Meanwhile,a new concept of alluvial river group is proposed as well as its definition,characteristics and distribution are preliminarily given,in order to promote the understanding on the formation and evolution of complex braided and meandering rivers in this new framework.