Ryohaku Mountains

A mountain range that spans four prefectures: Ishikawa, Fukui, Gifu, and Toyama. It is a mountain range that runs roughly north-south, centered on the twin peaks of Mt. Hakusan (2,702 meters) and Mt. Nogo Hakusan (1,617 meters), and was named "Ryohaku" (Ryohaku) after the Second World War, in honor of the two peaks of Mt. Hakusan. The area centered on Mt. Hakusan in the north is also called the Kaetsu Mountains, and is composed of many volcanoes at 1,600 to 1,700 meters, Hida gneiss rocks, the Mesozoic Tetori Group, and andesite. The area centered on Mt. Nogo Hakusan in the south is also called the Etsumi Mountains, and is composed of many mountains at 1,200 to 1,400 meters, and is composed of sedimentary rocks from the Carboniferous and Permian periods of the Paleozoic era. It is rich in alpine plants, bamboo grass, and deciduous broadleaf trees, with beech being an important material. It is an area of ​​power development, and large artificial lakes such as Lake Miboro, the Tedori River Dam, Lake Kuzuryu, the Sasou River Reservoir, and the Yokoyama Reservoir have been created. In the past, slash-and-burn agriculture and dezukuri farming were practiced, but this has now been replaced by cedar plantations. It is one of the areas with the heaviest snowfall, and depopulation is progressing.

[Takao Yagasaki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

石川、福井、岐阜、富山の4県にまたがる山地。白山（2702メートル）と能郷白山(のうごうはくさん)（1617メートル）の2峰を中心にしたほぼ南北方向の山地で、2峰の白山にちなみ、第二次世界大戦後「両白」と名づけられた。北部白山を中心とする地域は加越山地(かえつさんち)ともいい、1600～1700メートル級の火山が多く、飛騨片麻(ひだへんま)岩、中生代手取(てどり)層群、安山岩類からなる。南部の能郷白山を中心とする地域は越美山地(えつみさんち)ともいい、1200～1400メートル級の山が多く、古生代石炭紀、ペルム紀（二畳紀）の堆積(たいせき)岩類からなる。高山植物、ササ類、落葉広葉樹に富み、ブナは重要材である。電源開発地帯で、御母衣(みぼろ)湖、手取川ダム、九頭竜(くずりゅう)湖、笹生(さそう)川貯水池、横山貯水池など大人造湖がつくられた。かつては焼畑農業、出作りなどが行われたが、杉の植林に変わった。有数の豪雪地帯であり、過疎化が進んでいる。

［矢ヶ崎孝雄］

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