上海市青浦区景观格局的粒度效应分析

EFFECTS OF SPATIAL GRAIN SIZE ON LANDSCAPE PATTERN OF QINGPU DISTRICT IN SHANGHAI

以上海市青浦区为研究区域，基于ETM遥感影像数据和GIS技术，采用优势规则栅格聚合方法，对分类的ETM数据进行了粒度变换。以景观格局分析程序Fragstats3．3为分析工具，从景观类型水平和景观水平上研究了景观格局的空间粒度效应。研究结果表明：（1）不同的景观类型、不同的景观特征指数对粒度响应存在差异：居住景观和道路景观是对粒度响应最敏感的两种景观类型；形状指数、聚集度指数、斑块数量指数对粒度响应的敏感程度较高，多样性指数、均匀度指数、景观面积比例指数、分维数对粒度响应的敏感程度较低；此外，还发现优势景观随着粒度增加面积增大，形状规则的景观对粒度响应敏感程度低。（2）景观指数的粒度响应曲线存在尺度转折点，且多出现在40、60、80、120m，其中第一尺度区域多为20～40m或20～60m。第一尺度域是选择适宜粒度的较好取值范围，所以本研究中所用景观类型图进行景观指数计算的适宜粒度范围为30-40m。（3）研究发现由不同指数表征相同的生态现象可能会出现相反的粒度效应，在一定程度上体现了景观指数量化景观格局的局限性。

In this paper, the effects of spatial grain size on landscape pattern of Qingpu District of Shanghai City were discussed at the levels of class and landscape. To reveal the effects of grain size on landscape pattern, a series of graphs with different grid cells were constructed based on majority rules using the software Grid module of Arc/info. Fragstats3.3 was used as the landscape pattern analysis tool. The conclusions were drawn as followings： （1） There are obvious effects to respond to different grain sizes at classlevel and landscape-level. Among the 7 landscape types, road and inhabitant land changed significantly with different grain sizes; generally , dominant types of landscape were strengthened with grain size increasing; the regular landscape was not sensitive to changes of grain size. （2）Indices of landscape-level are variable with the increase of grain size. These indices are divided into four types： stable （ slowly decreasing）, monotone decreasing（no conspicuous scale inflexion） , decreasing （including conspicuous scale inflexion ）,increasing（including conspicuous scale inflexion ）. （3）The appropriate grain size should be chosen in the first scale domain,and the range of appropriate grain for landscape indices of Qingpu district was 30 m to 40 m.