Hii River

A river that flows northwest through eastern Shimane Prefecture and empties into Lake Shinji. It is 153 km long and has a drainage area of ​​2,550 square km. It is a first-class river. It originates from Mt. Sentsuzan in the Chugoku Mountains, which is on the border between Izumo (Shimane Prefecture) and Hoki (Tottori Prefecture), and flows out into the Izumo Plain together with the Omaki River, Ai River, Mitoya River, and others, before turning east and flowing into Lake Shinji. It has 223 tributaries. It once flowed west in the Izumo Plain and emptied into Taisha Bay in the Sea of ​​Japan, but due to several floods it began to flow east, and according to one theory it began to flow completely east in 1639 (Kan'ei 16). The upper reaches of the river are weathered granite mountains, where in the olden days the iron-hole-filtering process (using water to filter ores) was popular, forming an elevated river that frequently flooded. As a result, the lower reaches became alluvial, and new rice fields were developed, with the lake shoreline moving eastward about 5km. Scattered villages of houses surrounded by Tsuiji pines are built on the banks of the old riverbed. In Kisuki-cho, Unnan City, houses built on piles of earth to escape flooding can be seen. Construction is underway to excavate a spillway from the downstream area of ​​Kurihara, Izumo City, towards the Kobe River. The upper reaches of the river correspond to the Hinokawa River in the Kojiki and Nihon Shoki, and are known as the place where Susanoo-no-Mikoto defeated the Yamata-no-Orochi Serpent.

[Akifumi Nomoto]

"Reprint of "Hii River History" edited by Nagase Sadakazu (1977, Izumo Local History Publishing Association)"

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

島根県東部を北西流して宍道(しんじ)湖に注ぐ川。延長153キロメートル。流域面積2550平方キロメートル。一級河川。出雲(いずも)（島根県）と伯耆(ほうき)（鳥取県）の境にある中国山地の船通山(せんつうざん)に源をもち、大馬木(おおまき)川、阿井(あい)川、三刀屋(みとや)川などをあわせて出雲平野に出、向きを東に変えて宍道湖に流入する。支流数223。かつては出雲平野で西流して日本海の大社湾に注いでいたが、数度の洪水により東流するようになり、一説によると1639年（寛永16）完全に東流する。上流は風化した花崗(かこう)岩山地で古くは鉄穴(かんな)流し（水流による比重選鉱）が盛んで、天井川をなし、しばしば大氾濫(はんらん)した。その結果下流は沖積化し新田の造成が進み、湖岸線は約5キロメートル東進した。旧河道の堤防上に築地(ついじ)松に囲まれた家屋の散村をのせる。雲南(うんなん)市木次(きすき)町では水害逃れの盛り土した「一文上り(いちもんあがり)」の家屋をみる。下流の出雲市来原(くりはら)付近から神戸(かんど)川に向けて放水路開削工事が進められている。上流は記紀の簸川(ひのかわ)にあたり、素戔嗚尊(すさのおのみこと)の八岐大蛇(やまたのおろち)退治の地として知られる。

［野本晃史］

『長瀬定一編『斐伊川史』復刻版（1977・出雲郷土誌刊行会）』

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