Chikuho coalfields

Located in the Onga River basin in northern Fukuoka Prefecture, this is one of the largest coalfields in Japan. It covers an area of ​​approximately 800 square kilometers and is centered around the five cities of Tagawa, Kama, Iizuka, Nogata, and Nakama. The coal-bearing layers are made up of three groups of layers in the Paleogene, Ashiya, Otsuji, and Nogata, with the lowest group, Nogata, being the main coal-bearing layer. It mainly produces weakly caking bituminous coal, with reserves of approximately 2.5 billion tons. It has the longest history of development in Japan, with coal mining beginning at the end of the 15th century for home use by local farmers, and being used for salt production during the Kyoho era (1716-1736). Full-scale development began in the 1870s, and the founding of the Yawata Iron Works accelerated development. At the end of the Meiji period, it accounted for more than half of the nation's coal production, and in 1940 (Showa 15), it recorded a record high of 20.77 million tons, becoming an important location for the Kitakyushu Industrial Zone and playing a major role in the development of Japanese industry as a whole. After World War II, in 1957 (Showa 32), coal production recovered to 15 million tons, but in the 1960s, the industry began to decline due to the promotion of rationalization policies for the coal industry, and many coal mines, including Mitsui Tagawa Coal Mine, the largest in Chikuho, Mitsubishi Iizuka, Nippon Steel Futase, Aso, and Kaijima, closed one after another, and by 1983, there were almost no coal mines in operation, and the lights of the Chikuho coalfield went out. As a result, the Chikuho region was hit with a devastating blow, and the population dropped sharply due to the emergence of many unemployed people and the occurrence of mining pollution. In order to promote the region, efforts were made to attract businesses through the Coal Mining Region Promotion Temporary Measures Act (1961) and other measures, but most of the businesses are small-scale and it is difficult to say that sufficient results have been achieved. Currently, large-scale industrial parks are being developed, mainly in the northern part of the region, and Toyota Motor Kyushu began operations in Miyata Town (now Miyawaka City) in 1992 (Heisei 4), and there are high hopes for the area to develop into an industrial zone following the Kitakyushu Industrial Zone.

[Masaaki Ishiguro]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

福岡県北部、遠賀川(おんが)流域にある全国有数の炭田。田川(たがわ)、嘉麻(かま)、飯塚(いいづか)、直方(のおがた)、中間(なかま)の5市を中心に面積約800平方キロメートル。夾炭層(きょうたんそう)は古第三紀層の芦屋(あしや)、大辻(おおつじ)、直方の三層群で、最下位の直方層群を主要夾炭層とし、おもに弱粘結性の瀝青炭(れきせいたん)を産し、埋蔵量は約25億トン。日本ではもっとも開発の歴史が古く、15世紀末には地元農家の家庭用として採炭が始まり、享保(きょうほう)年間（1716～1736）に製塩用に利用されるようになったが、明治10年代より本格的な開発が始められ、八幡製鉄所(やはたせいてつじょ)の創業が発展を加速させた。明治末期には全国出炭量の過半を占め、1940年（昭和15）には史上最高2077万トンの出炭量を記録、北九州工業地帯の重要な立地条件となり、日本産業全体の発展にも大きな役割を果たした。第二次世界大戦後、1957年（昭和32）に出炭量は1500万トンまで回復したが、1960年代に入り石炭産業の合理化政策の推進によって衰退を始め、最盛期には300近くあった炭鉱も、筑豊最大の三井田川炭鉱(みついたがわたんこう)をはじめ、三菱(みつびし)飯塚、日鉄二瀬(ふたせ)、麻生(あそう)、貝島など多数の炭鉱が次々に閉山、1983年には稼行中の炭鉱はほぼ皆無となり、筑豊炭田の灯は消えた。その結果、筑豊地域は壊滅的な打撃を受けて、多数の失業者の出現、鉱害の発生などにより人口は激減した。地域振興のために産炭地域振興臨時措置法（1961）などによって企業誘致が進んだが、小規模なものが多く、十分な成果があがっているとはいいがたい。現在北部を中心に大規模工業団地が造成され、1992年（平成4）に宮田(みやた)町（現、宮若市）でトヨタ自動車九州が操業を開始するなど、北九州工業地帯に続く工業地帯としての発展が期待されている。

［石黒正紀］

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