黄河三角洲地区土壤盐渍化特征及其剖面类型分析

Analysis on Salinity Characteristics and Profile Types of Saline Soils in the Yellow River Delta

通过主成分分析和Q型聚类方法,研究了黄河三角洲地区典型地块土壤盐渍化特征,并对该地区土壤盐分剖面构型的分类进行了探讨。结果表明:研究区土壤含盐量普遍较高,总体上盐分分布呈较强的表聚性和变异性;土壤积盐可由盐分含量、离子组成特征、碱化特征以及外源影响因子4个主成分来反映,其累计贡献率达86.21%。聚类分析结果表明,研究区土壤盐分剖面可以明显分为表聚型、底聚型和平均型3类,在数量上以表聚型和底聚型为主;其中表聚型分布于研究区东部和南部,底聚型分布在西部和西北部;不同盐分剖面类型反映了植被类型和土地利用方式的差异,人为农业措施是形成底聚型和平均型盐分剖面的最直接因素。该研究结果为黄河三角洲地区盐渍土地的分区、改良、管理以及合理利用提供了理论基础和实践依据。

The characteristics of soil salinization in typical field of the Yellow River Delta was studied by the application of principle component analysis and hierarchical cluster analysis, and the classification of soil salinity profile types in our study area was also explored. The results showed that soil salinity was overall high and salt accumulation at the surface soil layer was generally significant, and soil salinity exhibited strong variation in both vertical and horizontal orientations. Soil salinity could be reflected by four principle components that were soil salt content, ion components, alkalization characteristics and exterior factors, and the cumulative contribution of these principle components added up to 86.21%. Hierarchical cluster analysis results indicated that salinity profile types could be obviously classified into inverted, normal and even, and the predominant salinity profile types in our study area were inverted and normal. The inverted salinity profiles mostly distributed in the east and north of the study area, while the normal salinity profiles mainly located in the west and northwest. The distribution patterns of salinity profile types reflected the vegetation types and land use patterns to some extent, and human agricultural activity was the crucial reason for the formation of normal and even salinity profile types. The research results can serve as a theoretical and practical reference to the partition, amelioration, management and rational utilization of saline soils in the Yellow River Delta.