Niihama Plain - Niihama Heiya

An alluvial plain formed by the Kokuryo River and its tributaries, centered on the Niihama area in eastern Ehime Prefecture. It covers an area of ​​approximately 35 square kilometers. Just eight kilometers from the coast of Hiuchinada, the Ishizuchi Great Fault Escarpment of the Median Tectonic Line runs east-west, and the Kokuryo River and other rivers flowing down from there create a complex alluvial fan below the cliff, which is followed by floodplains and deltas. As the river is underground and there is little surface water, there is a lot of farmland. Large-scale reclamation has been carried out on the right bank of the Kokuryo River estuary since early modern times, and on the left bank during the Showa period.

[Kazuo Fukaishi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

愛媛県東部の新居浜市域を中心にした国領(こくりょう)川とその支流による沖積平野。面積約35平方キロメートル。燧灘(ひうちなだ)沿岸からわずか8キロメートルを隔てて中央構造線の石鎚(いしづち)大断層崖(がい)が東西方向に走り、そこから流下する国領川などが崖下に複合扇状地をつくり、さらに氾濫(はんらん)原、三角州と続く。河川は伏流し地表水は少ないので、畑地が多い。国領川河口右岸は近世より、左岸は昭和期に大規模な埋立てが行われた。

［深石一夫］

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