| 长江上游屏山至宜昌河道泥沙存贮量的变化及其地貌学意义 |
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| 引用本文： | 许炯心.长江上游屏山至宜昌河道泥沙存贮量的变化及其地貌学意义[J].第四纪研究,2008,28(4):569-577. |
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| 作者姓名： | 许炯心 |
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| 作者单位： | 中国科学院地理科学与资源研究所,中国科学院水循环与地表过程重点实验室,北京100101 |
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| 基金项目： | 国家自然科学基金项目
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国家重点基础研究发展规划项目 |
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| 摘 要： | 通过河流输沙分析研究了长江上游河道的悬移质泥沙存贮量及其变化。结果表明,1956～2000年屏山-宜昌河段历年的河道存贮量的变化可以划分为3个阶段,即两个泥沙存贮期和1个泥沙释放期。1956～1968年为第1个泥沙存贮期,河道泥沙存贮累积性增加,累计存贮量为4.0126×108t,与这一时期人类活动导致的流域侵蚀加剧有密切的关系;1969～1983年为泥沙释放期,累积释放量为2.6533×108t——支流水库大量修建,拦截了泥沙,下泄泥沙减少,进入长江干流的泥沙减少,含沙量降低,使得干流中前期存贮的泥沙发生侵蚀而释放;1984～2000年为第2个泥沙存贮期,累积存贮量为4.0733×108t。金沙江下游重点产沙区产沙量增加,进入长江干流的泥沙增多,葛洲坝水库建成后投入运行,三峡水库大坝的建设,也导致长江干流河道中泥沙存贮量的增大。输入沙量、输出沙量和与流域面平均年降水量之间均存在较明显的正相关关系,而存贮量与降水量不相关,说明河道泥沙存贮对于降水量的变化不敏感。屏山-宜昌河道泥沙输移比的时间变化大致可以分为两个阶段,即在1956～1982年河道泥沙输移比呈增加趋势,1983～2000年则呈减小趋势。这种变化可以用河道泥沙存贮的变化来解释。长江上游屏山-宜昌河段河道泥沙存贮的时间变化与中游宜昌-武汉河段泥沙冲淤量的时间变化相位在一定程度上是相反的,说明上游河道泥沙存贮增多会导致中游河道泥沙存贮减少,上游河道泥沙存贮减少会导致中游河道泥沙存贮增多。
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| 关 键 词： | 泥沙存贮 山区河流 泥沙输移比 长江上游 |
| 收稿时间： | 2008-01-30 |
| 修稿时间： | 2008-05-04 |
VARIATION IN CHANNEL SEDIMENT STORAGE IN THE SECTION BETWEEN PINGSHAN AND YICHANG OF THE UPPER REACHES OF CHANGJIANG RIVER AND SOME GEOMORPHIC IMPLICATIONS |
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| Xu Jiongxin.VARIATION IN CHANNEL SEDIMENT STORAGE IN THE SECTION BETWEEN PINGSHAN AND YICHANG OF THE UPPER REACHES OF CHANGJIANG RIVER AND SOME GEOMORPHIC IMPLICATIONS[J].Quaternary Sciences,2008,28(4):569-577. |
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| Authors: | Xu Jiongxin |
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| Institution: | Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Key Laboratory for Water Cycle and Related Land Surface Processes, Chinese Academy of Sciences, Beijing 100101 |
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| Abstract: | Based on data of suspended sediment load from hydrometric stations,a study has been made on channel sediment storage in the section between Pingshan and Yichang of the upper reaches of Changjiang River and its temporal variation.During the period of 1956～2000,the channel sediment storage can be divided into 3 stages,two of sediment storage and one of sediment releasing.The stage from 1956 to 1968 was the first stage of sediment storage,with the cumulative storage being 401.26 million t.In this stage,the channel sediment storage increased,in response to the intensified soil erosion in the drainage basin.The stage from 1969 to 1983 was a period of sediment releasing,with the cumulative releasing being 265.33 million t.In this stage,many reservoirs were built,resulting in a reduction in sediment load of the Changjiang River.Therefore,sediment concentration declined,and the previously stored sediment in the channel was eroded and released.The stage from 1984 to 2000 was the second stage of sediment storage,with the cumulative storage being 407.33 million t.In this stage,the sediment yielded from the lower reaches of Jinshajiang River increased,and supplied more sediment to the Changjiang River.The construction of Gezhouba Dam and Three Gorges Dam also increased channel sediment storage in the upper reaches of Changjiang River.It has been found out that,for the studied river section,close correlation exists between annual sediment-input,sediment-output,and annual precipitation,but no correlation between annual sediment storage and annual precipitation has been found,indicating that channel sediment storage is un-sensitive to annual precipitation.The variation in channel sediment delivery ratio shows two stages.From 1956～1982,it tended to increase,and afterwards,decrease.This can be explained by the variation in channel sediment storage.It has been also found out that the temporal variation in channel sediment storage in the section between Pingshan and Yichang is inverse to some degree to that between Yichang and Wuhan in the middle reaches of Changjiang River.This indicates that the increase in channel sediment storage in the upstream may result in a decrease in the downstream. |
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| Keywords: | sediment storage sediment delivery upper reaches of Changjiang River |
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