In order to research engineering geological properties of the soil in Zhenlai of western Jilin, especially the dispersivity of soil, the authors carried out the basic physicocbemical test and dispersivity identification test. The results show that the dispersivity of the soil increases with the increase of depth within 0-30 cm （surface soil） ; it decreases as the depth increases within in 30-100 cm. Furthermore, the statistical analysis of the dispersivity indexes and physicochemical propertity indexes show that the DP is positively linear correlated with total soluble salt content, sodium ion content, ESP, pH and organic matter content. Meanwhile, it is negatively linear correlated with clay content, and the linear relationship is better. Through the study of the dispersion mechanism of soil samples, it can be concluded that sodium montmorillonite, higher percentage of exchangeable sodium and high pH are the main reasons for the dispersion of soils in western Jilin.
Principal Component Analysis(PCA) can simplify the structure of database by replacing multi-dimensional parameters with relatively less comprehensive variables in order to ensure the minimum lost in initial data.In this paper,eighteen black soil samples from different sites were tested and thirteen distinctive indexes were chosen to evaluate the degeneration of black soil.By using principal component analysis,variables of thirteen dimensions can be diminished to six unrelated principal indexes.Analysis shows that the soluble salt content,Fulvic acids(FA) and aggregation degree have a high weighing coefficient,indicating these three indexes are the major parts for the evaluation of black soil degradation.It also provides a new path to the degenerated black soil treatment in Northeast China.
NIU Cencen WANG Qing WEN Xiuyu GUO Yuan ZHAGN Penglei ZHU Rongyue HE Xianhui
