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选取河南省作为研究区域,对其DEM数据进行处理得到河南省地形分类图。以地形分类图为基础用经典的土壤构成组分多样性算法计算丰富度指数S、多样性指数H′和均匀度指数E,再使用改进的仙农熵指数(Yh)计算不同地形下每个土类面积占本土类总面积的比例及其在1 km×1 km网格尺度下的土壤空间分布多样性。结果表明:河南省主要有平原、丘陵、山地和盆地4种地形,且以平原地形为主;河南省有15种土类,从平原、丘陵、山地到盆地地形,土壤丰富度依次递减,且随着地形面积的增加,土类丰富度指数S也不断增加且二者拟合函数为多项式函数;多样性指数H′测度分析显示,4种地形下从土类、亚类到土属多样性值均处于递增趋势,且从平原、丘陵、山地到盆地地形,土类和亚类的多样性值呈“先上升后下降”趋势,土属一直呈“下降”趋势;土属的均匀程度高于土类和亚类的均匀程度,且从平原、丘陵、山地到盆地地形均匀度指数E/土壤构成组分多样性均呈“先上升再下降”趋势;土壤分支率与构成组分多样性间的拟合函数均为多项式函数。经研究,河南省地形和土壤的形成及空间分布多样性有密切的联系,如河南省广阔的平原赋予了潮土分布的地域背景条件,山地地形中山间谷底仅有少量潮土分布,然而平原地形下潮土空间分布斑块多、斑块面积大、空间分布多样性指数高而成为平原地形下空间分布离散性强的优势土壤类型,同时平原也是省内极少面积盐土和碱土仅有的分布区域;同样,山地和丘陵地形下面积最大且空间分布多样性值最大的土类均为褐土;盆地地形以黄褐土、砂姜黑土为主。通过对比,不同地形下指数Yh在空间分布表达上优于其他指数。
Henan Province is selected as the research area, and its DEM data is processed to obtain the topographic map of Henan Province. Based on the topographic classification map, the richness index S, diversity index H ’and evenness index E were calculated using the classical soil compositional component diversity algorithm. Then, the improved index of Shannon entropy (Yh) The ratio of soil area to the total area of the soil type and its spatial distribution diversity under 1 km × 1 km grid scale. The results show that there are four kinds of terrain in Henan Province, including plain, hills, mountains and basins, and are dominated by plain terrain. There are 15 kinds of soil in Henan Province, from plains, hills and mountains to basin topography, with decreasing soil fertility With the increase of the terrain area, the soil abundance index S also increased continuously and the fitting function of the two plots was a polynomial function. The analysis of the diversity index H ’showed that under the four types of terrain, The values of the soil were in an increasing trend, and the diversity values from the plain, hills and mountains to the basin topography, soil types and subclasses showed the trend of “rising first then falling” Is more uniform than that of soils and subgroups, and the diversity of terrane evenness index E / soil composition components from plain to hilly to mountainous basin shows the trend of “rising first and then decreasing”; the soil bifurcation rate And the constituent functions of the composition between the fitting function are polynomial functions. According to the research, there is a close relationship between topography and soil formation and spatial distribution diversity in Henan Province. For example, the vast plain in Henan Province gives the geographical background of the distribution of the alluvial soil. There is only a small amount of alluvial soil distributed in the valley bottom of the mountainous terrain, The terrain has many spatial distribution patches, large plaque area and high spatial diversity index, which makes it a dominant soil type with strong spatial distribution and dispersibility under the plain terrain. At the same time, the plain is also the only area with a very small area of salt and alkaline earth in the province In the same way, the soil with the largest area under the mountainous and hilly terrain and the largest spatial distribution diversity is cinnamon soil. The topography of the basin is dominated by yellow cinnamon soil and sago lime black soil. By contrast, index Yh is superior to other indices in spatial distribution under different terrain.