1世纪至20世纪中期上荆江流域河道与水环境变迁——基于荆江洪水位历史变迁的考察

清中叶以降,清宫档三汛(桃花汛、伏汛、秋汛)安澜奏本中所见荆江洪水位开始日益上涨,咸丰、同治年间,藕池、松滋决口向洞庭湖分流后,水势稍有缓解,至光绪年间复又急速抬升。不断上涨的洪水位对江北入江河流造成了两方面影响: 其一为河道的变迁,其二为水环境的变化。在沮漳河流域,涉及长江百里洲的变迁,沮漳河入江口的变动,长江主泓迁移,下百里洲靠岸及洲尾东摆引发沮漳河下游延长,以及山水、江水相互顶托造成水环境淤积。在玛瑙河流域,则表现为荆江洪水位抬升对河水的顶托现象,导致入江尾闾沼泽化。

River Courses and Water Environment Changes in the Upper Jingjiang River Basin (100-1950): An Investigation Based on Flood Records

In the mid-Qing Dynasty, the flood level of the Jingjiang River (a section of the Yangtze River) began to rise and was repeatedly recorded in the Sanxun Anlan Zouben of the Qing Palace Memorials and Archives of the Grand Council. During the Xianfeng and Tongzhi reigns, after the Ouchi and Songzi dikes collapsed and the main flow diverged to the Dongting Lake, the flood level eased temporarily and rose again rapidly in the Guangxu’s reign. The rising flood level affected the courses, and water environment of the rivers flowing southward into the Yangtze River. In the Juzhang River Basin, this involves the expansion, separation, and approaching northward of the Bailizhou Island in the Yangtze River, shifts of the estuary of the Juzhang River, the shift of the main Yangtze River course, the extension of the lower reaches of the Juzhang River caused by the adjoining of Lower Bailizhou with the east bank, as well as the silt caused by the counter-balanced effect of the river flow and mountain torrents. In the Ma’nao River Basin, the backwater effect of the rising flood level at the estuary turned the area into a swamp.