长沙市土地利用格局变化的空间粒度效应

Spatial Grain Size Effect on Land Use Pattern Changes in Changsha City

基于2003年、2006年、2009年及2013年的遥感图像对长沙市土地利用进行分类,在Arc GIS 10.0、ENVI4.8、Fragstats 4.0和Excel 2007软件的支持下,通过上推尺度像元的比例占优法改变空间粒度,从类型水平和景观水平上分析了土地利用格局变化的粒度效应。得出以下结论:1类型水平上,随着粒度的增大,各土地类型的指数呈现出3种变化趋势:增大、减小及无明显规律;随着时间的变化,空间粒度越小,对斑块密度及斑块形状指数变化的影响越明显。空间粒度越大,对斑块结合度和斑块集聚度变化的影响越明显。2景观水平上,随着粒度的增大,蔓延度指数先减小后基本不变;香农多样性指数和香农均匀度指数缓慢减小;随着时间的变化,蔓延度指数呈减小的趋势,香农多样性指数和均匀度指数呈增大的趋势。90 m是本研究中分析空间粒度的最佳值。

By using the remote images in 2003, 2006, 2009, 2013, the article classifies the land use of Changsha City. With the support of ArcGIS 10.0, ENVI 4.8, Fragstats 4.0 and Excel 2007 software, it analyzed spatial grain effect of land use pattern changes by changing the space grain sizes on class level pattern indices and landscape level pattern indices. The optimal proportion method was used. We have drawn the follow conclusions： 1） On class level, with the increase of spatial grain sizes, all kinds of index change present three trends, increase, decrease, regularity is not obvious. With the change of time, the smaller the spatial grain sizes, the more the effect of patch plaque density changes and patch shape index changes, the bigger the spatial grain sizes, the more the effect of patch cohesion index changes and patch aggregation changes. 2）On landscape level, with the increase of spatial grain sizes, the contagion index decrease before they are basically remain unchanged, the Shannon＇ s diversity index and Shannon＇ s evenness index is slowly reduced. As the change of time, the contagion index showed a trend of decrease on the whole, the Shannon＇ s diversity index and Shannon＇ s evenness index showed a trend of increase. The size of 90 m is the optimization analysis spatial grain sizes in this study.