メトロマニラ郊外部における都市化と樹木被覆地の変容に関する研究

Abstract

Green spaces covered by trees in urbanized area are known to have many ecological functions. It is, therefore, strongly needed to understand the features of green spaces distribution and it's change in order to establish a sound environmental plan, especially in Asian mega-cities where rapid urbanization is being observed. In this study, GIS analysis and field survey were integrated to examine the changes in green spaces in Metro Manila, Philippines, one of the most rapidly growing cities in Southeast Asia. First, the aerial photos taken in 1997 and the satellite image (Quickbird image) taken in 2004 were used to examine the change of green spaces in the urban fringe of Metro Manila. The tree cover ratio of the study site increased from 10.9% (1997) to 12.4% (2004). Vegetation survey, then, was implemented and the factors that caused the increase were identified for newly created tree cover area through the field investigation and interviews to the residents. The tree plantation by the residents contributed 80% of the increase. These indicated that the plantation by the residents was considered to be very active although they pay more attention to if it's edible than if it's good for environment. This trend of increase was, still, favorable for the improvement of environmental condition in urban fringe areas.