2006 年 26 巻 4 号 p. 296-303
This paper represents the monitoring method of a carbon sink preservation activity for the global warming countermeasure using a high-resolution satellite image. The objective of this study is to assess the diffusion of organic farming in Papua New Guinea (P.N.G.) by applying the object-based image analysis to land-use classification. Slash-and-burn agriculture, also known as shifting cultivation, is commonly employed in P.N.G. With a low population density, forests have sufficient time to recover before being slashed and burned again. However, the significant increase in the population of P.N.G. accelerates the expansion of slash-and-burn fields, which causes decreasing of forests. Therefore, the prevention system against spreading the slash-and-burn fields should be established. Recently, the project that serves the prevention system and preserves forests has been practiced in Palmalmal village in P.N.G. This project promotes the organic farming so that the slash-and-burn fields could stand the recursive use. Moreover, the rice cultivation is diffused, which enables them to maintain the stable food, because rice could be stored for a long time.
In this paper, we estimate the slash-and-burn field as one of the evaluating indices of the project. The object-based land-use classification is proposed to identify the slash-and-burn field. This preliminary examination indicates that the satellite image analysis is applicable to extract basic information for assessing the diffusion of organic farming, especially where the precise map is not available. We also discuss the estimation method of rice cultivating area.