著者

平川 南

出版者

国立歴史民俗博物館

雑誌

国立歴史民俗博物館研究報告 (ISSN:02867400)

巻号頁・発行日

vol.96, pp.351-391, 2002-03

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今,歴史学に対して新たな研究視点として,日本の歴史における自然と人間の交渉史の実像を明確に示すことが求められている。そこで,本稿は,自然環境としての河川との関わりを通して地域支配の実態を明らかにしたい。以下,本稿では,地域支配と河川について,次の四つの視点から究明を試みた。① これまでの地理的関係から内陸部とみられた地域の中に,外洋に面する河口と同様に,直線的に河川が外洋につながり,"第二河口"と位置づけられた地域が存在したのではないか。② 宮都や城柵のような国家施設造営にあたり,それらの施設は水運の便を十分に活用するために宮都や城柵内部に河川を引き込む形で占地している。しかし,それは洪水という災害を同時に抱え込むことを意味している。いいかえれば,これまで長岡京や志波(しわ)城について,その廃都や廃城は水害を直接的理由としてきたが,それは造営当初から十分に予測できたのではないか。③ 律令体制下に,郡の津(つ)(港)として外洋に望む河口部や津を管理する「津司(つのつかさ)」が設置された。その津司では「津長(つのおさ)」が責任者として,津に出入する客などに応じたのであろう。④ 9世紀後半から10世紀にかけて,各地で新たに台頭してきた豪族層の拠点施設は,河川を取り込み,船着場を設け,施設内では手工業的生産や農業経営が活発に行われたことが近年の発掘調査の成果から知ることができる。さらに付け加えて,古代の河川の運行においても,近世同様,曳船(ひきふね)方式が活発に実施された点を強調した。The current state of Japanese historical studies is one which strives to show an accurate representation of the history of interaction between man and nature. In this paper, the author tries to identify the circumstances of regional control through man's involvement with rivers as a natural environment. The writer investigated the following four points in terms of regional control and rivers. 1. Among places that have been considered inland areas, there existed locations that had rivers that connected directly to the ocean, and were in reality considered "secondary estuaries", the same as estuaries facing onto the ocean. The Kitakami River in the Iwai region of the ancient province of Mutsu and the Futohi River in the Shimotsuke Samukawa region are such examples. 2. Facilities constructed by the nation, such as at Kyuto (Place of Royal Authority) and Josaku (fort), were located inland to draw rivers in to fully utilize water transport. However, that raised the problem of the natural disaster of flooding at the same time. In other words, up to this point flood damage has been thought to be the direct cause of the disuse of the old capital in Nagaokakyo or Shiwajo Fort. However, this potentiality for flooding could have been enough estimated from the start of construction. Thus, it is possible to consider that it was expected from the construction planning stage that this was a sequenced undertaking in which a transfer would occur from Nagaokakyo to Heiankyo and from Shiwajo Fort to Tokutanjo Fort. 3. "Tsu no tsukasa" (the port office) was established to control harbors and estuaries that looked out on the ocean and functioned as district ports, was established under the Ritsuryo system. The activities of "Tsu no Osa" (head official of ports) who was responsible for overseeing those entering and leaving the ports are known from the mokkan (wooden tablets with official message) excavated from sites located in the Iwaki county of Mutsu province and the Kaga county of Echigo province. 4. Results of excavation surveys in recent years from the Kadoshin Sites in Niigata Prefecture and the Furushida Sites in Yamagata Prefecture show that from the latter half of the ninth century to the tenth century, facilities that were the bases for powerful clans appeared in various places. Rivers were rerouted, boat docks were built and agricultural administration and handicraft production activities took place within the facilities. In addition, it was emphasized that movement along the rivers in ancient times was, as in modern times, conducted by tug-boats.In this paper, the writer has outlined the points above concerned the relationship between regional control in ancient time and rivers. In the future, he hopes to further analyze the various conditions of rivers as natural environment and to further investigate how the rivers were involved in the formation of regional society.