公元9世纪以来长江潮区界的迁移过程重建  

Reconstruction of the Changjiang River tidal-limit movement since the ninth century AD

作　　者：张忍顺[1] 高超[2] 汪亚平 Zhang Ren-Shun;Gao Chao;Wang Ya-Ping(School of Geography,Nanjing Normal University,Nanjing 210023,China;School of Geography and Ocean Science,Nanjing University,Nanjing 210093,China;State Key Laboratory of Estuarine and Coastal Research,School of Maine Sciences,East China Normal University,Shanghai 200241,China)

机构地区：[1]南京师范大学地理科学学院,江苏南京210023 [2]南京大学地理与海洋科学学院,江苏南京210093 [3]华东师范大学河口海岸学国家重点实验室,海洋科学学院,上海200241

出　　处：《古地理学报》2020年第6期1221-1232,共12页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:41625021);上海市教育委员会科研创新计划(编号:2019-01-07-00-05-E00027)联合资助。

摘　　要：海潮从长江口沿江上溯,可达内陆600 km以上的潮区界,为世界大河所少见。中国古人就对这一现象有所感知,在一些文学著作与地方志中可找到长江潮区界及其变化的信息。在公元3世纪末、4世纪初,长江的潮波已越过柴桑(今江西九江);在公元9世纪早期,长江枯水期的潮区界已经退到九江的湓浦口;在13世纪最后的十几年,长江潮区界下移至皖赣交界的小孤山附近。从公元9世纪早期到13世纪晚期的470年间,潮区界下移了64 km,年均为0.136 km/a。20世纪中叶以来的学者普遍认为,长江的潮区界又下移至安徽铜陵的大通镇。可见,长江干流在尚未被大型水利工程截断以前,长江潮区界持续向下游移动。在13世纪末至20世纪中叶的670年中,长江潮区界下移170 km,年均为0.254 km/a,速率几乎是前一时期的2倍。分析表明,潮区界下移速率和三角洲向海的淤长有关,还可能受气候变化的重要影响。对比发现,在长江干流大型水利工程开始蓄水的几年后、九江站流量约8440 m3/s的特大枯水时期,潮汐引起的水位上涨影响可达九江附近、即1100多年前中唐时代的潮区界位置。The tide can now propagate upstream for more than 600 km from the Changjiang River estuary to hinterland,which is rare in the world.In China,information and records reflecting tidal limit and its movement in the Changjiang River can be found from some ancient books,literary works and local chronicles.At the end of the 3 rd and the beginning of the 4 th century AD,the tide limit of the Changjiang River reached the upstream of Chaisang(now named Jiujiang in Jiangxi Province).At the early 9 th century,the tide limit in the dry season retreated to the Penpukou in Jiujiang.In the last ten years of the 13 th century,the tidal limit moved back to the Xiaogushan Mountain near the border between Anhui Province and Jiangxi Province.By the middle of the 20 th century,the modern researchers generally agreed that the tidal limit retreated to Datong in Anhui Province.Before the main stream of the Changjiang River was cut off by large-scale water conservancy projects,the tide limit had retreated seaward continuously.From the3 rd decade of the 9 th century to the last decade of the 13 th century,the tide limit moved downstream64 km during the 470 years,with an average annual rate of 0.136 km/a.During the 670 years from the end of the 13 th century to the middle of the 20 th century,the tide limit had moved downstream 170 km,with an average annual rate of 0.254 km/a,almost twice as much as that of the previous period.We suggest the climate change accounted for the different retreat rate of the tidal limit between the two periods discussed.In addition,a recent study found that during the extremely dry periods,when the discharge of Jiujiang station was about 8440 m3/s,the tidal limit reached near Jiujiang.In the years when the water conservancy project on the main stream of the Changjiang River began to store water,the tide limit actually returned to the previous position of the middle Tang Dynasty,i.e.1100 years ago.

关 键 词：长江 潮区界 九江(湓浦口) 小孤山 安徽大通 

分 类 号：P512.32[天文地球—地质学]