歴史的視点から見た干潟環境の変化と人との係わりに関する研究 : 福岡・今津干潟を例に

干潟の保全再生の取り組みが全国で始まっている.その際, 環境目標の設定が重要であるが過去の再現は困難なことが多い.福岡都市圏の今津干潟は古代から栄え, 貝塚を始め多くの歴史的資料が蓄積されている.本研究ではこれらの資料を分析し, 古代から昭和50年代までは干潟と人の係わりが密接であったこと, 地域では干潟環境の悪化は砂質干潟の泥質化が原因だとされていたが, 出土貝類の状況から泥干潟が古代から存在していたことなどを明らかにした.本研究のアプローチは各地の干潟再生に貴重な情報を提供すると考えられる.

In the recent years, restoration of tidal flat has been carried out in Japan. In those cases, we need an environmental goal of restoration project. However, it is difficult to remake past condition. The Imazu Tidal Flat in the sphere of the Fukuoka City has prospered from ancient times, and a lot of historical materials including the kitchen midden has been accumulated. In this research, we investigated the historical change of physical environment and human impact relationships in the Imazu tidal flat, and it was clarified that the tidal flat and person's relations were close from ancient times to 1975's. It was thought the cause of the deterioration of the tidal flat was that a sandy tidal flat had become mud, but the excavation shellfishes' situations gave proof that the muddy tidal flat had existed from from ancient times. Our results provided an important evidence for restoration of tidal flat of various places.

© 2006 社団法人 土木学会