Coastal Landform Evolution and Environmental Changein the Late Holocene

本研究旨在阐明晚全新世海岸地貌演变与环境变化，特别是海平面变化、沉积物供应和人类影响的关系。田野调查在全日本(小池县、松原县)、北海道(大平县)、静冈县(松原县)、爱知县、三江县(Umitsu、Kawase县)、冲绳县(长谷川县、藤本县)和泰国(藤本县、Umitsu县)等地进行。详细研究了德知川和熊津河低地的地貌演化，阐明了古海岸线的变化。还研究了泰国湄南河三角洲和澳大利亚Shoalaven低地的海岸变化和地貌演变。这些研究阐明了详细的海岸地貌演变与沉积物供应和海平面变化的关系。这些关系在以往的研究中没有得到很好的阐明。长谷川对冲绳石垣岛珊瑚断裂的研究表明，这种现象与气温和人类活动的季节变化，特别是土地利用的变化有关。Fujimoto研究了冲绳和泰国沿海低地晚全新世的海平面变化和碳浓度，并讨论了海平面的微小波动和红树林泥炭的形成。他澄清说，包括红树林泥炭在内的地下沉积物中的碳浓度大于树干和树叶部分。小池总结了日本沿海地貌的特点。松原还讨论了日本沿海壁垒的演变。

This research aims to clarify the late Holocene coastal landform evolution in relation to environmental change especially sea-level change, sediment supply and human impact. Field research were done in whole Japan (Koike, Matsubara) Hokkaido (Ohira) , Shizuoka (Matsubara), Aichi, Mie (Umitsu, Kawase), Okinawa (Hasegawa, Fujimoto) prefectures and Thailand (Fujimoto, Umitsu) and so on. Detail land form evolution was studied in the Tokachi-gawa and Kumozu-gawa lowlands and clarifeid the change of paleo-coastlines. Coastal change and land form evolution was also studied in the Chao Phraya delta, Thailand and Shoalhaven Lowland, Australia. These researches clarified the detail coastal land form evolution in relation to the sediment supply and sea-level change. These relationships werenot well clarified in the former studies. Coral breaching in the Ishigaki Island, Okinawa was studied by Hasagawa, and clarified that the phenomenon relates to the seasonal change of temperature and human activities especially change of land use. Late Holocene sea-level change and carbon concentration in the coastal lowland of Okinawa and Thailand were studied by Fujimoto, and discussed the minor sea-level fluctuation and mangrove peat formation. He clarified that the carbon concentration in the subsurface sediment including mangrove peat is largerthan the trunk and leaf parts. Characteristics of the Japanese coastal land forms were summarized by Koike. Matsubara also discussed on the evolution of Japanese coastal barriers.