Muikamachi Basin - Muikamachi basin

A mountain basin in the southeastern part of Niigata Prefecture, upstream of the Uono River. It is also called the Uonuma Basin. To the west, the steep slopes of the tilting land mass of the Uonuma Hills border the Tokamachi Basin, and low-lying terraces have developed due to small ground movements at the end of the Quaternary Period. Since World War II, the area has been converted into rice paddies through national reclamation projects. In the eastern part, there is a series of alluvial fans caused by small tributaries flowing out of the Echigo Sanzan mountains, and there are many fan-centered plains such as Yairohara, Jounaihara, and Noborigawahara. Reclamation projects have also been carried out here, but due to the rice production reduction policy, it has not been possible to open the land, and the area is struggling to produce specialty products due to the conversion to field crops. With the completion of the Shimizu Tunnel, the center of the basin became a main artery for the era of high-speed transportation in the greater Tokyo area, and construction work on the JR Joetsu Line, Joetsu Shinkansen, Kan'etsu Expressway, National Route 17, and other lines was concentrated there, leading to rapid development and a complete change in the character of the four towns of Yuzawa, Shiozawa, Muikamachi, and Yamato (Shiozawa, Muikamachi, and Yamato are now part of Minamiuonuma City). The town attracts more than 10 million tourists a year as a town of hot springs, ski resorts, and guesthouses.

[Hisao Yamazaki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

新潟県南東部、魚野川(うおのがわ)上流にある山間盆地。魚沼盆地ともいう。西は魚沼丘陵の傾動地塊の急斜面で十日町盆地と境し、第四紀末の小地盤運動による低位段丘面が発達している。第二次世界大戦後の国営開拓事業による水田化が進んでいる。東部は越後(えちご)三山から流れ出す小支流による扇状地群が連続し、八色原(やいろっぱら)、城内原(じょうないはら)、登川原(のぼりがわはら)などの扇央原野が多く、ここも開拓事業が進められたが、減反政策で開田できず、畑作転換で特産物づくりに苦労している。清水(しみず)トンネルの貫通で、盆地中央は首都圏高速交通時代の幹線になり、JR上越線、上越新幹線、関越自動車道、国道17号などの工事が集中し、急激に開発が進み、湯沢(ゆざわ)、塩沢(しおざわ)、六日町、大和(やまと)の四つの町の性格を一変させた（塩沢町、六日町、大和町は現南魚沼市）。温泉、スキー場、民宿の町として年間1000万を超える観光客を集めている。

［山崎久雄］

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