基于综合指数模型的黄土高原自然区划研究

基于1971～2000年气象数据、TM影像和DEM,结合因子分析、ArcGIS中的栅格计算和方差分析,获得了黄土高原的自然区划模型,对该地区进行区域划分,然后运用方差分析对划分结果进行了检验。结果表明,因子分析中剔除了年均最大风速和年均风速2个变量,采用其他变量进行分析。黄土高原综合指数分区呈现出从东南向西北的层状分布,气象要素大小按级区顺序递增或递减,随着此方向地形起伏逐渐增大,植被覆盖程度减小,土壤有机质含量减少、颜色变浅、质地变得轻粗,侵蚀强度也依次增强。采用单因素方差分析分别检验3个自然区中各站点的气象要素均值是否存在差异性,得出年均最低气温的差异性最大,在3个自然区的区别中处于主导地位;方差分析的多重比较反映出两两自然区间的气象要素差异显著。说明用综合指数对黄土高原进行区域划分具有一定的科学性。

Research on the Natural Regionalization in Loess Plateau Based on Model of Composite Index

According to the multiple meteorological data,TM and DEM data from 1971 to 2007,the natural regionalization model of loess plateau was constructed based on factor analysis,the raster calculation in ArcGIS and the analysis of variance,the area of loess plateau was regionalized,and the regionalization results were verified with the analysis of variance.As indicated by the results,the factors of annual maximum wind speed and average wind speed were excluded for analysis.The aggregative index of loess plateau showed a layered distribution from southeast to northwest.Meteorological elements were increasing or decreasing according to the order of level areas,towards this direction terrain increases,vegetation cover reduces,organic matter content of soil decreases,color of soil fades,texture becomes light crude and erosion intensity is enhanced.Based on the single factor analysis of variance,we analyzed the difference of the mean data of meteorological elements in three natural areas.The difference of average annual minimum temperature was the most.Multiple variance analysis reflected the remarkable diversity of meteorological elements between each two natural areas.Therefore,it was scientific to divide loess plateau by using aggregative index.