Taihu Lake

A lake that straddles the provinces of Jiangsu and Zhejiang in China. Its former names were Zhenze and Liuze. With an area of ​​2,213 square kilometers, it is the fourth largest freshwater lake in China. The lake surface is low, averaging 3 meters above sea level, and shallow, averaging 2 meters deep. There are dozens of islands in the lake, including Mount Xidongting and Mount Maji. Originally, it was a bay where seawater had infiltrated into a sunken basin, but the mud and sand carried by the Yangtze River accumulated there, making it a shallow sea. Furthermore, sandbars extended southeast from the southern bank of the Yangtze River and northeast from the northern bank of the Qiantang River, and these two sandbars surrounded the shallow sea to form the lagoon "Ancient Lake Taihu." Ancient Lake Taihu shrank due to the accumulation of mud and sand from the East and West Lioxi and Nanxi rivers flowing from Mount Tianmu, becoming the shallow lake we know today. The lake's water drains into the Yangtze River via the Liuhe River, Wusong River, and Huangpu River, but these rivers are narrow and have gentle gradients, making it difficult for water to flow, and rising water levels in the lake often caused disasters in the surrounding areas. There are countless lakes and marshes in the surrounding area that are remnants of the ancient Lake Taihu, and waterways run in all directions, forming a water town area. Development of the surrounding area began in earnest during the Tang and Song dynasties, and in the Ming and Qing dynasties, in addition to rice cultivation and sericulture, various rural handicraft industries developed. Currently, it plays an important role as a source of irrigation water and as a transportation route.

[Kazuo Hayashi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中国、江蘇(こうそ)・浙江(せっこう)両省にまたがる湖。旧称は震沢(しんたく)、笠沢(りゅうたく)。面積2213平方キロメートル、中国で四番目に大きい淡水湖である。湖面の標高は平均3メートルで低く、水深は平均2メートルで浅い。湖中には西洞庭(せいどうてい)山、馬迹(ばしゃやく)山など数十の島がある。もとは陥没した盆地に海水が浸入した海湾であったが、そこへ揚子江(ようすこう)が運搬してきた泥砂が堆積(たいせき)して浅海となった。さらに揚子江南岸より南東方向へ、また銭塘(せんとう)江北岸からも北東方向へ砂州が延伸し、これら2本の砂州が浅海を囲い込んで潟湖(せきこ)の「古太湖」を形成した。古太湖は、天目山より流れる東・西の苕渓(ちょうけい)や南渓などが堆積する泥砂により縮小し、現在の浅い湖となった。湖の水は瀏河(りゅうが)、呉淞(ごしょう)江、黄浦(こうほ)江を通って揚子江に排水されるが、これらの河川は狭く、勾配(こうばい)が緩やかなため水が流れにくく、湖の水位上昇により、周辺地区にしばしば災害をもたらした。周辺には古太湖の名残(なごり)である無数の湖沼があり、また縦横無尽に水路が走り水郷地帯を形成している。周囲の開発は唐・宋(そう)代から本格化し、明(みん)・清(しん)代には水稲や養蚕に加え、さまざまな農村手工業が発達した。現在は灌漑(かんがい)用水源として、また交通路として重要な役割を果たしている。

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