Yamaguchi Basin

The basin is located in the middle of the Fushino River, almost in the center of Yamaguchi Prefecture, and occupies the center of Yamaguchi City. It is a lowland that subsided along a tectonic line running northeastward, and the Nihozu Narrows downstream formed a bag-shaped topography. The flat basin floor is 10 to 30 meters above sea level, measuring about 4 kilometers east to west and 5 kilometers north to south. The basin is only about 10 kilometers from the Seto Inland Sea coast, and it has been observed that there are many sea and land breezes from the northeast to southwest, but there is a large temperature difference, and there are many days with frost and fog, indicating a fairly inland basin climate. There are many ruins from the Yayoi and Kofun periods in the foothills, and the remains of the ancient jori system, which covers more than 500 cho, can be seen widely throughout the lowlands. The city of Yamaguchi has developed on the alluvial fan of the Ichinosaka River that juts out from the northern corner.

[Hajime Miura]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

山口県のほぼ中央、椹野(ふしの)川の中流に開けた盆地で、山口市の中央部を占める。北東方向に走る構造線に沿って沈降した埋積低地で、下流の仁保津狭隘(にほづきょうあい)によって袋状の地形となり、東西約4キロメートル、南北約5キロメートルで平坦(へいたん)な盆地床の高度は10～30メートル。瀬戸内沿岸からわずか十数キロメートル入った盆地で、北東―南西の海陸風の多いことが観測されているが、気温較差は大きく、霜日数や霧日数も多く、かなり内陸性の盆地気候を示す。山麓(さんろく)帯には弥生(やよい)・古墳期の遺跡が多く、低地一帯には500町以上に及ぶ古代条里制の遺構が広く認められる。北隅から張り出した一ノ坂川扇状地上に山口市街地が発達している。

［三浦　肇］

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