Showing papers in "Geographical reports of Tokyo Metropolitan University in 1977"

Landscape evaluation for the rehabilitation of an eroded drainage basin in the northern part of Okinawa Island, Southewest Japan

Abstract: In the northern part of Okinawa Island landscape management based on natural geo€cosystems in a drainage basin has been traditionally carried on. A conservation-based management system of the landscape has been historically adopted to the character of small drainage basins in the humid sub-tropical environment (Nago City, lg74). Both land and land use have been managed by the people according to the landscape slrstems in the drainage basins. Here the concept of land will be defined as a complex of natural conditions or resources in the landscape, and landscape system as a complex of land rystem and land-use qystem (Mabbutt, 1968). Such traditional management systems, however, have broken down in some parts of the teglon through agricultural modernization or urbanization. Especially cultivation of pineapple (Ananas comonrs) or construction of public institutions on the hillsides from l0 iyears before cause an abrupt change of the landscape. Environmental deterioration in ,drainage basin has rapidly occurred through the development of hillsides, for example, artificial reformation of land or renovation of pineapple field using bulldozers. Serious soil ,erosion through dynamic processes in the drainage basins has occurred, which has not 'only ehanged the land itself but also brought some confusion of land use through an inflow of reddish soil to channel, paddy field or seashore. The conservation problems of both land and land use in correspondance with landscape systems in drainage basin have been also under discussion.