河流平面型态（河型）是河流地貌学和河流动力学的一个交叉研究领域和热点问题，认识河型转化机理对于理解河流演变规律，指导河流科学治理有重要理论和现实意义。由于问题的复杂性，有关的认识仍以经验性为主，缺乏坚实可信的理论支撑，且以往对多处于输沙非平衡态的干旱区河流关注不够。以检验近年发展起来的冲积河流平衡理论在输沙非平衡态干旱区河流演变中的应用性为目的，本研究以地处干旱区的塔里木河为主要对象，实际观测和理论分析相结合，将阐明河道型态与水沙过程、滨河植被及河谷地貌等的动态响应关系，探求塔里木河河型发育成因；确定推动河型转化的关键因子及阈值范围，建立河型与关键因子的耦合模型，揭示河型转化机理，明晰触发河型转化的临界条件。最后，探讨人类活动影响下塔里木河地貌未来演变趋势和可能的河型转化方向。项目成果将拓展对干旱区河流地貌特征、发育成因和演变规律的认识，并为塔里木河综合治理和流域绿洲可持续发展提供参考。

Channel planform pattern (channel pattern) is one of a trans-discipline research topic and also a hot scientific question in both Fluvial Morphology and River Dynamics. Grasping mechanism of channel pattern transformation bears theoretic and realistic significance in understanding fluvial processes and guiding scientific training of rivers. Due to its great complexity, studies on this topic are still dominated with empirical analyses, lacking convincing theoretical support, and especially short of attention on dryland rivers which mostly belong to non-equilibrium system. With the aim of examining the suitability of equilibrium theory for alluvial rivers which developed over the last more than 10 years on non-equilibrium river in arid regions, with a case study of Tarim River which located in a hyper-arid region in Northwest China, and combing field observation and theoretic analysis, this research will investigate the dynamic relations between channel pattern and flow-sediment processes, riparian vegetation and valley morphology to explore the causes of channel pattern development along Tarim River; then determine the key factors pushing channel pattern transformation and their threshold ranges, and set up a coupling model between channel pattern and the key factors to reveal the mechanism behind channel pattern transformation and determine the thredhold which inducing channel pattern transformation. Finally, the future fluvial processes and possible channel pattern transformation direction of the Tarim River under the impacts of large-scale human interventions will be also discussed. The potential outputs of this project will broaden the knowledge of dryland rivers on fluvial morphology feature, evolution causes and processes; meanwhile, it will be helpful to comprehensive management of the Tarim River and sustainable development of the Oasis in the basin.