澜沧江中段典型河谷植被景观格局的空间尺度效应研究

Study on Spatial Scale Effect of Vegetation Landscape Patterns in Typical Valleys of the Middle Lancang River

采用2002年Landsat ETM+影像解译澜沧江流域中段典型河谷的植被景观,以相对面积设置不同空间幅度梯度,以不同像元大小设置空间粒度梯度,分别分析其对研究区景观水平景观格局指数随空间幅度和空间粒度大小的变化规律,并采用曲线回归拟合各景观格局指数随空间幅度和粒度的变化趋势。结果表明:1)河谷地区景观格局指数对空间幅度和空间粒度具有尺度依赖性,随着空间幅度和空间粒度的变化,多数景观格局指数都有明显的响应,且能用曲线估计模型来进行模拟或预测;2)空间幅度分析中的平均缀块形状指数和空间粒度分析中的缀块面积标准差等景观格局指数的模拟曲线存在明显的尺度拐点,其中相对面积(空间幅度)为0.1~0.2,空间粒度为240~300 m。本研究可为河谷地区景观格局分析的尺度确定提供参考依据。

Landsat ETM+image in 2002 were selected to interpret and draw the vegetation landscape map in the middle reach of Lancang River.The spatial extent gradients in relative area and spatial grain gradients in different pixel sizes were set,and the changes of landscape pattern index in the landscape scale with spatial extent and grain were analyzed,then the curve regression was used to fit the change trend of landscape pattern index with spatial extent and grain.The results show that the landscape pattern indices in the river valley are scale dependent on the spatial scale,and with the change of spatial extent and grain,most landscape pattern indices have obvious response,and can be simulated or predicted by curve estimation model;the simulation curves of landscape pattern indices such as the average patch shape index in spatial extent analysis and the standard deviation of patch area in spatial grain analysis have obvious scale inflection points,and the relative area(spatial extent)is 0.1–0.2,the spatial pixel sizes are 240–300 m.So,it can provide theoretical support for the scale determination of landscape pattern analysis in river valley area.