尺度分析对景观格局指标的影响

采用优势规则和随机规则为基础的两种尺度分析方法，对分类的TM数据进行了尺度变换分析。结果表明，随着尺度(粒度)增加，优势规则处理法使景观中优势类型的面积增加，非优势类型的面积减少，随机规则处理法使各景观类型的面积基本上保持不变，随尺度变大，整个景观和多数类型的最大斑块面积指标增加；最小斑块面积等于尺度大小的平方；平均斑块面积都增加；斑块数迅速减少，在优势规则系列中，多样性指标减小，而在随机规则处理中，基本没有变化，聚集度随尺度的增大而减小，但测量尺度固定的情况下，随图分辨率的提高而增大，随尺度的增加，Moran’s Ⅰ指标减小，景观类型在空间上趋于随机分布，但是测量尺度固定的情况下，随图分辨率的提高而增大，景观类型在空间上趋于聚集分布。

Scaling effects on landscape pattern indice

The methods of spatial data aggregation based on majority and random rules were used in this study to reveal the scaling effects on landscape pattern in a classified TM imagery with 8 land cover types. For the majority rule based aggregations,the proportion of most common cover types increased slowly,while that of less common cover types decreased rapidly with increasing grain. For random rule based aggregation,each cover remained its original area on the aggregated maps. The largest patch sizes of shrub decreased,and those of the others increased in the majority rule based aggregations with increasing scales. For random rule,the largest patch size of water (smallest cover type) decreased,but that of the others increased. The smallest patch size of each cover type was equal to the square of grain sizes. The average patch size of each cover type increased with increasing scales. However,the average patch size of dominant cover types increased rapidly in majority rule based aggregations,while that of less common cover types increased rapidly in random rule based aggregation. The patch count of each cover types decreased substantially with increasing grain. Random rule based aggregation made landscape more fragmented and remained more patches. The diversity decreased in majority rule based aggregation,and maintained its original value in random rule based aggregation with increasing scales. Aggregation indices decreased with increasing map and measurement resolution,and the landscape became more aggregated in majority rule based aggregation. However,under fixed measurement resolution (e.g.,30 m),aggregation indices increased and cover types were more clustered with increasing resolution. Moran's I decreased rapidly with increasing measurement and map resolution,and each cover type tended to be arranged randomly and independently in space. However,under fixed measurement resolution (e.g.,30 m),Moran's I increased and cover types were more clustered on aggregated maps than on original map with increasing map resolution.