Straight river: its formation and speciality

来源 :Journal of Geographical Sciences | 被引量 : 0次 | 上传用户:whq59
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider spatial and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it possible for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the aforementioned questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sedimentation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper concluded that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation. Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider space and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it may for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the said questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sediment ation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper wire that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation.
其他文献
盈利的网络公司只有两种,荆林波博士认为,一种是纯粹提供网络应用技术服务的公司,它们有自己的专利,有自己的竞争优势,能够占领市场,比如网络运营商通过垄断资源获利,比如提
 萍乡钢铁有限责任公司宣传部聂友华来稿认为当前企业思想政治工作应坚持在“六个结合”上下功夫。   1.坚持思想政治工作与加强理想信念教育相结合,帮助干部职工坚定实现
递推思想及递推方法常见于数列有关题目求解中,然而在实际中却有许多别的数学问题与此思想相结合形成一类“整合性问题”.解决这类问题时如果能融递推方法于题目之中, Recur
由于投入于环境卫生的基础设施较缺乏,生态环境因大量的城市垃圾而受到严重的破坏。据调查统计表明,我国历年堆积的城市垃圾已达70亿吨,占地5亿多平方米,平均每年产生的量大
第l期40一30kaBP青藏高原及邻区高温大降水事件的特征、影响及原因探讨………………………… ……………………………施雅风 贾玉连 于 革杨达源 范云崎李世杰 王云飞(1)太湖
以丙硫苯咪唑200mg、Bid、连续三d与甲苯咪唑200mg、Bid、连续三d分别治疗钩虫感染者12例和10例。丙硫苯咪唑治后第1天幼虫发育率为0.25%,治后第2—5d均无虫卵发育为幼虫。甲
20 0 2年 10月 15~ 16日由中国能源研究会和云南省科学技术厅主办 ,中国能源研究会地热专业委员会、云南省地热开发办公室和腾冲县人民政府承办的“云南腾冲地区地热综合开发
经济落后地区如何通过“两思”教育来促进经济发展 ?陵川县委针对本县实际,“思源找因,思进求变”,取得了良好效果。 一、首先要消除认识误区  陵川是一个刚摆脱贫困、向建设
慢性肝炎,是由病毒、药物、酒精或其它原因引起的肝脏炎症。其组织学及生物化学的异常表征持续时间长而且无明显好转,但不少作者认为病程超过6个月者称为慢性。单纯以病程来
针对传统强夯采用人工脱钩的落锤方式存在的弊端,本文研究探讨了一种电磁式强夯施工技术。电磁式机械强夯通过电磁力吸附重锤至预定高度后,将磁极反转,推动重锤向下夯击地面,