Ōi River
Ōi River | |
---|---|
Native name | 大井川 (Japanese) |
Physical characteristics | |
Source | |
• location | Mount Aino, Akaishi Mountains, Japan[1] |
• elevation | 3,189 m (10,463 ft)[1] |
Mouth | |
• location | Suruga Bay |
• elevation | 0 m (0 ft) |
Length | 168 km (104 mi)[1] |
Basin size | 1,280 km2 (490 sq mi)[1] |
Discharge | |
• average | 76.40 m3/s (2,698 cu ft/s) |
Basin features | |
Bridges | Hōrai Bridge |
Dams | Tashiro Dam |
The Ōi River (大井川, Ōi-gawa) is a river in Shizuoka Prefecture, Japan.
Geography
The Ōi River flows from the Akaishi Mountains, the branch of the Japanese Southern Alps which form the border between Shizuoka, Nagano and Yamanashi prefectures.[1] These mountains, with peaks ranging from 2,000 to 3,000 metres (6,600 to 9,800 ft), are characterized by heavy rainfall (up to 3,000 millimetres (120 in) per year) and deep V-shaped valleys.[1] The river follows a generally southern course, with seven wide bends in its central region, before exiting into Suruga Bay in the Philippine Sea.
History
The Ōi River is mentioned in Nara period records as forming the border between Tōtōmi and Suruga Provinces. However, due to shifting of the course of the river over the centuries, by the late Muromachi period, this was not always the case.
During the
Because of this, the Ōi River was regarded as the most difficult part of the Tōkaidō. A well-known lyric states:
- 箱根八里は馬でも越すが、越すに越されぬ大井川
- Hakone hachiri wa uma demo kosu ga, kosu ni kosarenu Ōigawa
- Even horses can cross eight ri (=31 km) of Hakone, but the Ōi River is hard to get over in any way.
The river was bridged shortly after the
Hydroelectric development
The potential of the Ōi River valley for hydroelectric power development was realized by the
In 1906, a
After the end of World War II, the
Tourism
The Ōigawa Railway runs two lines in the Ōi River valley. Originally built to facilitate dam construction, both lines are now primarily run for tourists, and include a popular steam locomotive run into the mountains.