Ashida River

A river that flows through the eastern part of Hiroshima Prefecture. It is a first-class river. Its source is in the Daiwacho area of ​​Mihara City in the Kibi Plateau, and it flows east, passing through Sera Town, Fuchu City, and other areas, before emptying into the Seto Inland Sea in Fukuyama City. It is 86 km long and has a drainage area of ​​860 square kilometers. The Fukuyama Plain is the delta created by this river. It is the largest river in the eastern part of the prefecture, and is used for agricultural water, urban water, and industrial water. In preparation for water shortages, the Mikawa Dam (1960) and Hattabara Dam (1998) were built upstream. There is a dam at the mouth of the river, which was built at a cost of 15.1 billion yen (construction began in 1972 and completed in 1981) to calm the water flow during floods and allow the water to flow into the sea little by little, and to obtain 170,000 tons of industrial water per day. The completion of the dam has made it possible to prevent seawater from flowing back into the river, but pollution around the estuary dam has worsened, with issues such as blue-green algae blooming.

Near the mouth of the river, near Kusado-cho in Fukuyama City, a port town that flourished during the Kamakura period was buried beneath the riverbed, but it began to be excavated in earnest in 1973 and was named the Kusado-Sengen-cho Ruins. Also known as the "Pompeii of Japan," the valuable archaeological remains that were excavated are now housed at the Prefectural Museum of History (opened in 1989 in Fukuyama City).

[Kitagawa Kenji]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

広島県東部を流れる川。一級河川。吉備(きび)高原の三原(みはら)市大和(だいわ)町地区が源流で、東流しながら世羅(せら)町、府中市などを経て福山市で瀬戸内海に注ぐ。延長86キロメートル、流域面積860平方キロメートル。福山平野はこの川のつくったデルタである。県東部では最大の河川で、農業用水のほか都市用水、工業用水としても利用される。水不足に備え、上流に三川(みかわ)ダム（1960）・八田原(はったばら)ダム（1998）を設けている。河口には堰(せき)がつくられているが、この堰は、洪水の際に水流を穏やかにし、水を少しずつ海に流すためと、1日17万トンの工業用水を得る目的で、151億円かけてつくられた（1972年着工、1981年完成）。堰の完成により、海水の川への逆流を防げるようになったが、アオコが発生するなど、河口堰付近の汚染が進んでいる。

　河口に近い福山市草戸町付近には、鎌倉時代に栄えた港町が河底に埋まっていたが、1973年（昭和48）から本格的に発掘され、草戸千軒町遺跡と名づけられた。「日本のポンペイ」とも称され、発掘された考古学上貴重な遺物などは、県立歴史博物館（1989年開館、福山市）に収蔵されている。

［北川建次］

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