空间粒度变化对沂蒙山区景观格局指数的影响

Effects of spatial grain change on the landscape pattern indices in Yimeng Mountain area of Shandong Province,East China

基于2004年沂蒙山区不同空间幅度的土壤侵蚀强度图,利用GIS技术和Fragstats软件,选择8个景观格局指数,探讨沂蒙山区不同空间幅度的景观格局指数在20～65m范围内的粒度效应,并对景观格局指数进行函数拟合分析。结果表明:(1)各景观格局指数随粒度增加表现出不同的变化趋势,具体包括上升趋势、下降趋势和变化不明显3种情况;(2)对于两种不同空间幅度的研究区域,景观格局指数研究的第一尺度域为(20,35),最佳空间粒度均为35m;(3)通过一元线性回归分析对所选8个景观格局指数进行拟合,斑块数量、斑块密度、景观形状指数、周长面积分维数、蔓延度指数和聚集度指数能够很好地拟合出其变化趋势;而最大斑块指数、Shannon多样性指数的拟合效果不太理想。

Based on the graphs of soil erosion intensity at different spatial scopes in Yimeng Mountain area in 2004, and by using GIS technology and Fragstats software, 8 landscape pattern indices were selected to study the effects of the grain size of landscape pattern indices at different spatial scopes within the range of 20 to 65 m in Yimeng Mountain area, and the functional fitting analysis was applied to analyze the landscape pattern indices. With the increase of grain size, the landscape pattern indices showed different change trends, i. e. , rising, declining, or unconspic- uous change. As for the two study areas with different spatial scopes, the first scale domain of landscape pattern index was （20, 35 ）, and the optimal spatial grain sizes were all 35 m. Through the fitting of the selected 8 landscape pattern indices by one-dimensional linear regres- sion analysis, it was found that the NP, PD, LSI, PAFRAC, CONTAG, and AI could fit the change trends of the indices well, while the fitting results of LPI and SHDI were unsatisfactory.