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根据土壤资源的特点,对陕北于旱地区旱作土壤的10个样本7个指标,作了模糊综合评价,结果用被评价样本总值(V_i)与标准样本总值(V_o)的贴近度(N)之间的关系N=V_o/V_i表示.N值越大,则样本U_i与标准样本U_o越相似.这样可用于土地分级,编制土壤资源评价等.再将合成指标值进行标准化处理,计算出各土壤U_i的相似度(r_(ij)),得到满足对称性和自反性的模糊相似矩阵((?)),绘出10个土样的模糊聚类“最大树”.再按不同要求(λ)分出不同类.聚类分析对确定土地类型,设计合理的土地利用方案具有重要的意义.
According to the characteristics of soil resources, fuzzy comprehensive evaluation was made on seven indexes of 10 samples of dryland soil in dry land in northern Shaanxi Province. The results were compared with the closeness of the total sample value (V_i) (N), N = V_o / V_i, the larger the value of N, the more similar the sample U_i is to the standard sample U_o, so it can be used for land classification and compilation of soil resource evaluation, etc. Then the synthetic index value is standardized, Calculate the similarity of each soil U_i (r_ (ij)), get the fuzzy similarity matrix ((?)) That satisfies the symmetry and reflexivity, draw the fuzzy cluster “maximum tree” of 10 soil samples Different requirements (λ) separate different classes.Cluster analysis is of great significance to determine the type of land and a well-designed land use plan.