基于3S技术的北京市植被覆盖空间格局变化研究

Research on Spatial Pattern Changes of Vegetation Cover in Beijing Based on 3S

处理三期Landsat TM影像,计算NDVI,利用等密度模型提取植被覆盖度并通过计算景观指标对植被覆盖变化分析。分析表明:北京市植被覆盖程度整体呈下降趋势。全植被覆盖斑块面积整体下降,分布趋于离散;高植被覆盖斑块面积减少,形状趋于复杂;中植被覆盖斑块面积整体增加,有团聚分布趋势;低植被覆盖斑块面积显著增加,有团聚分布趋势;无植被覆盖斑块面积稍有上升,破碎度高,有团聚分布趋势。

NDVI were calculated based on processing three periods of lands,at TM images. It extracted vegetation coverage by the equilibrium density model and analyzed the vegetation cover changes through the landscape indexes computation. It showed that the whole vegetation coverage was decreased in Beijing. The area of whole-vegetation cover patches was decreased and discrete distribution. The area of high-vegetation cover patches was also decreased and complex. The area of mid-vegetation cover patches was increased and agglomeration distribution. And the area of low-vegetation cover patches was significantly increased and agglomeration distribution. Tne area of non-vegetation cover patches which had high breaking degree and agglomeration distribution was slightly increased.