基于半方差分析的东祁连山地景观特征尺度

采用美国陆地资源卫星3个时相的遥感图像,运用半方差分析的方法,对东祁连山地景观特征尺度进行研究。结果表明：（1）步长增大时,东祁连山地景观的特征尺度相应增大,但增加的幅度在时间上和方向上存在显著差异,若步长继续增大至数千米以上时,则不能较好地表现出景观格局的自相关性;（2）变程可有效地揭示出东祁连山地景观结构的各向异性,左对角方向上的特征尺度较大,景观结构的异质性最小,垂直、水平两个方向上的特征尺度较小,景观结构的异质性较高;（3）全球气候变暖及人为活动等生态过程对东祁连山地景观结构的异质性有明显影响,使得研究区景观格局的空间相关性减弱。

Characteristic Scale of Eastern Qilian Mountainous Landscape Based on Semivariance Analysis

By interpreting three remote sense images of Terra satellites of USA,the characteristic scale of Eastern Qilian mountainous landscape was analyzed based on semivariance analysis.The results showed the characteristic scale of Eastern Qilian mountainous landscape increased with the step size increasing,but the increased extent had significant difference in timing and direction,if the step size continued to increase to above thousands meters,the autocorrelation of landscape was not showed very well;the changing rate could effectively reveal the anisotropy of the structure of Eastern Qilian mountainous landscape,the characteristic scale was quite great in the left diagonal directions,and the heterogeneity of landscape pattern was the smallest,while the smaller characteristic scale and a high heterogeneity of landscape pattern in both horizontal and vertical directions.The ecological processes such as global warming and human activities had a significant effect on the heterogeneity of Eastern Qilian mountainous landscape pattern,which weaken the spatial correlation of landscape pattern.