Lake Kinshako

This artificial lake is located in Shikokuchuo City, eastern Ehime Prefecture. It is an artificial lake created by Yanase Dam, which was created by damming the Dozan River, a tributary of the Yoshino River, and is designated as Kinsako Prefectural Natural Park. The dam was completed in 1953 (Showa 28) and has a storage capacity of 30 million tons. In addition to generating electricity, it diverts water to irrigate 1,300 hectares of the Uma Plain. The geology of the surrounding area is Sanbagawa-type crystalline schist, which is subject to dynamic metamorphism and is prone to peeling, forming a schist-like and linear structure. This has been eroded by the valley, creating a colorful landscape with green (chlorite schist), red (pomegranate quartz schist), and black (black schist). There are also old and giant trees such as Japanese oak, Japanese wisteria, and Japanese juniper.

[Kazuo Fukaishi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

愛媛県東部、四国中央市にある人造湖。吉野川の支流銅山(どうざん)川をせき止めてつくられた柳瀬ダム(やなせだむ)の人造湖で金砂湖県立自然公園に指定されている。ダムの完成は1953年（昭和28）で、貯水量3000万トン。発電のほか分水によって宇摩平野1300ヘクタールの灌漑(かんがい)用水を送水する。付近の地質は三波川(さんばがわ)系結晶片岩で、動力変成作用を受けているため剥離(はくり)しやすく、片状、線状構造をなす。これが渓谷の侵食を受け、緑（緑泥片岩）、赤（紅簾(こうれん)石英片岩）、黒（黒色片岩）などの色彩に富む景観をつくる。また、シイ、ヤマフジ、イブキビャクシンなどの老巨木がある。

［深石一夫］

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