Sanbongihara

In eastern Aomori Prefecture, this alluvial plateau extends eastward from the foot of Mt. Hakkoda. It is about 30 km east to west and 15 km north to south. It is about 100 meters above sea level in the west and 10 meters above sea level in the east, continuing to the Pacific coast. The northern part faces Lake Ogawara, and the southern part is the Oirase River lowlands. Towada City is at the center of the plateau. It was once a barren wilderness with poor water supply, but in 1855 (Ansei 2), Nitobe Tsutomu, a samurai of Morioka (Nanbu) Domain, together with his eldest son Jujiro and grandson Shichiro (Inazo's eldest brother), began developing the area by drawing water from the Oirase River. Four years later, he completed the Inaogawa Waterway and succeeded in opening up rice fields. In the Meiji era, it was taken over by a private development company, and in 1937 (Showa 12) it became a national enterprise, and was roughly completed in 1965 (Showa 40).

[Hiroshi Yokoyama]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

青森県東部、八甲田(はっこうだ)山麓(さんろく)から東方に展開する洪積台地。東西約30キロメートル、南北約15キロメートル。標高は西部で約100メートル、東部は約10メートルで太平洋岸へ続く。北部は小川原(おがわら)湖に臨み、南部は奥入瀬(おいらせ)川低地となる。台地の中心は十和田市。かつては水利の悪い不毛の原野であったが、1855年（安政2）盛岡（南部）藩士新渡戸伝(にとべつとう)が長男十次郎、孫の七郎（稲造(いなぞう)の長兄）とともに奥入瀬川の水を引いて開拓に着手、4年後に稲生川水路(いなおいがわすいろ)を完成させ、開田に成功した。明治に入って民営の開拓会社に引き継がれ、1937年（昭和12）からは国営事業となり、1965年（昭和40）いちおうの完成をみた。

［横山　弘］

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