广州市植被覆盖度等级结构及其时空格局特征

Spatio-temporal pattern and hierachical characteristics of vegetation fraction from 1990 to 2005 in Guangzhou

城市化过程直接改变了城市景观,研究城市植被覆盖度及其景观特征动态变化,再现了人们对城市自然景观的干扰过程与强度,反映出城市生态环境质量。1990～2005年间,广州市经济发展迅速,同时也使城市植被系统经历了从严重破坏到逐步恢复的过程,用TM遥感影像解译区域植被覆盖度并进行其等级结构的时空特征研究。结果表明,1990～1995年间是区域植被破坏最严重的时期;以后的时段内,这种趋势在中心城区有所减缓,但没有根本改变,郊区从化市则从2000年起,植被系统未再受到破坏,表现为植被覆盖度增加,植被覆盖度等级结构也获得改善,而这一过程对全市的植被系统产生积极的影响作用。

Urbanization has changed the landscape structure of urban area. By studying the vegetation fraction and its pattern of urban vegetation, the changing process and the intensity of urban landscape could be emerged once again. Meanwhile, it indirectly makes know the eco-environmental state in city. From 1990 to 2005, vegetation system in Guangzhou was experienced a period of destroying and the next period of restoration. This procedure was studying by translating TM remote sensing image. Based on it, regional vegetation fraction and its grade structure were showed with the translated images. The research was also indicated that regional vegetation fraction was decreased seriously in whole study area-full Guangzhou, and until now the tendency to decrease vegetation fraction in city centre of Guangzhou is continuing, but being slowly. In suburb district-Conghua, vegetation system is becoming better and better. Its vegetation fraction is approaching the highest level in the past 15 years, and vegetation grade structure is more perfect. In vegetation system, high grade vegetation fraction is increasing. Vegetation system in Conghua is so important to impact the tendency of vegetation system in full Guangzhou.