基于 Moran’s I 指标的黄土坡耕地填洼量的空间自相关性研究

Study on spatial autocorrelation of depression storage in Loess sloping field based on Moran’s I

摘要:

在ArcGIS9.3 和SPSS16.0平台的支持下，通过Moran’s I指标对人工掏挖和人工锄耕措施下坡面填洼量的空间自相关性进行了分析，初步揭示了此2种耕作措施下坡面填洼量的空间分布格局。结果表明：全局Moran’s I小于或等于0，基本呈弱的负空间自相关；坡度对填洼量空间分布格局的影响不明显；填洼量的空间自相关性与填洼量大小有关。因此，填洼量空间格局呈大小交错，空间异质性较强的分布特征，但其所受填洼量大小的影响还需进一步研究。

Abstract:

The spatial distribution characteristics of depression storage in Loess sloping field was studied with the method of spatial autocorrelation based on Moran’s I, and firstly micro-DEM with the grid size of 0.002 m derived from tillage methods of artifical dig and artifical back hoe, has been established by ArcGIS9.3 software referring data from quantified elevation values determined by home-made laser scanner with the measured plot area of 1.34 m2. Then depression storage or volume was extracted from micro-DEM using ArcGIS9.3’ hydrology tools. The results showed that, 1) depression storage presented weakly negative spatial autocorrelation due to global Moran's I was less than or equal to 0, and also, 2）the relationship between slope and spatial pattern of depression was not clear, but, 3）it’s autocorrelation was related to the amount of depression storage. In summary, spatial distribution characteristics of depression storage in sloping field presented a size of staggered and strong spatial heterogeneity pattern.