| 河流堰塞的地貌响应 |
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| 引用本文： | 周丽琴,刘维明,赖忠平,王昊,曹广超.河流堰塞的地貌响应[J].第四纪研究,2019,39(2):366-380. |
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| 作者姓名： | 周丽琴 刘维明 赖忠平 王昊 曹广超 |
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| 作者单位： | 青海师范大学地理科学学院,青海 西宁 810008;中国科学院、水利部成都山地灾害与环境研究所,中国科学院山地灾害与地表过程重点实验室,四川 成都 610041;中国科学院、水利部成都山地灾害与环境研究所,中国科学院山地灾害与地表过程重点实验室,四川 成都 610041;汕头大学海洋科学学院,广东 汕头,515063;中国科学院青藏高原研究所,北京,100101;青海师范大学地理科学学院,青海 西宁 810008;青海师范大学, 青海省自然地理与环境过程重点实验室,青海 西宁 810008 |
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| 基金项目： | 国家自然科学基金;国家自然科学基金;清华大学水沙科学与水利水电工程国家重点实验室开放基金 |
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| 摘 要： | 堰塞作为一种极端地表过程,深刻影响着河流地貌的变化,特别是河流纵剖面的变化。其对河流纵剖面的影响主要体现在两方面:一方面,堰塞坝将抬高局地的侵蚀基准面,阻碍了上游河道侵蚀,形成河流裂点;另一方面,堰塞坝溃决往往形成大型/巨型洪水,造成下游河道和岸坡的剧烈侵蚀。稳定的堰塞坝形成后,在1~105 a的时间尺度上对河流裂点的发育以及河流纵剖面变化上甚至会超过构造、气候和岩性作用,占据主导。本文在简要概述堰塞地貌相关概念的基础上,介绍了部分河流堰塞的研究方法和案例,以及河流堰塞的发育过程和研究意义。目前多仅从堰塞坝与河流纵剖面的空间关系的相关性来论证其地貌响应,并且发现一些堰塞坝与河流纵剖面的相关性,但是也有一些古堰塞坝对现代河流纵剖面的影响并不显著,原因可能与堰塞坝规模、溃决洪水次数、堵江的持续时间和距今年代的不同有关,目前还缺乏深入研究。
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| 关 键 词： | 堰塞坝 河流裂点 河流纵剖面 溃决洪水 侵蚀 |
Geomorphologic response of river damming |
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| Zhou Liqin,Liu Weiming,Lai Zhongping,Wang Hao,Cao Guangchao.Geomorphologic response of river damming[J].Quaternary Sciences,2019,39(2):366-380. |
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| Authors: | Zhou Liqin Liu Weiming Lai Zhongping Wang Hao Cao Guangchao |
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| Institution: | (School of Geographic Science,Qinghai Normal University,Xining 810008,Qinghai;Key Laboratory of Mountain Hazards and Earth Surface Processes,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,Sichuan;Institute of Marine Science,Shantou University,Shantou 515063,Guangdong;Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101;Qinghai Province Key Laboratory of Physical Geography and Environment Process,Qinghai Normal University,Xining 810008,Qinghai) |
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| Abstract: | The evolution of river landscape is comprehensively influenced of various factors,such as bedrock lithology,sediment supply,tectonic activities,vegatation and climate changes.An increasing number of studies suggested that damming incidents occurred on the stream channel are capable of significantly modifing the morphology of longitudinal profiles of river display.For example,knickpoints formed by repeatedly river damming during the glacial and interglacial periods could retard headward erosion along the river channel,which play a critical role in maintaining the integrity of the Tibetan Plateau.However,previous studies rarely take this into account when geomorphologic analyses were carried out using quantitative morphological parameters of the river longitudinal profile.The influences of river damming on the evolution of river longitudinal profiles are mainly reflected as follows.Firstly,the dams would rise the local base level of erosion,resulting in upstream aggradation,enlargement of valley width.In addition,the dams would act as a river knickpoint to retard the regressive erosion towards upstream channel.A forementioned influences primarily depends on the height and duration of the dams blocking.Lastly,the dam failures usually trigger flood of great magnitude causing severe downstream erosion of and longitudinal profile of river adjusts itself to equilibrium until the knickpoint vanish due to the focused downward erosion at the dam body.This process would promote river erosion,which mainly depends on the magnitude,frequency,and occurring time of outburst floods.Extreme events such as river damming and outburst floods are important processes for channel aggradation and erosion of rivers.However,an adequate understanding of their impacts on the evolution of river geomorphology is lacking in China.Hence,we conduct a brief overview of studies on river-damming and its influences on river geomorphology in this paper,taking related researches in southern New Zealand and Swiss Alps,the edge of the Tibetan Plateau,eastern Oregon and western Turkey as examples.To date,studies on responses of river system to damming incidents have only be carried out based on the spatial correlation between dams and knickpoints of the river.In oder to quantify the geomorphic effect of the river damming,it is necessary to obtain the detailed parameters of magnitude,frequency and time of duration of the river dammingand consequent outburst floods. |
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| Keywords: | damming effect river longitudinal profile knickpoint erosion outburst floods |
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