天津滨海土壤盐分离子相关性及采样密度研究

土壤盐渍化是一个世界性的生态问题。天津滨海地区土壤长期遭受海水及高矿化潜水共同作用,土壤盐渍化现象分布广泛。本文选取天津滨海新区太平镇作为典型地区,研究了土壤主要盐分离子的相关性,另外对工作区采样点进行了随机均匀抽稀试验,探讨了不同采样密度对土壤盐渍化插值结果和评价结果的影响。研究表明:天津滨海地区土壤易溶盐中Na+、Cl-所占比例具有绝对优势;土壤中全Cl、Cl-与全盐量具有非常好的相关性,随机均匀抽取少量样本加测全盐量,建立全Cl与全盐量的相关方程可以比较准确地推算出所有样本的全盐量;大密度采样有利于提高样本的代表性,若要满足相对误差合格率≥80%的要求,采样密度不应低于4点/km2,另外用于评价盐渍化等级的采样密度不宜低于1点/km2。

Correlation of soil salt ions and sampling densities in Tianjin coastal area

Soil salinization is a worldwide ecological problem. In Tianjin coastal area, soil has long suffered from sea water and high mineralization diving, so salinization is widely distributed. Choosing Taiping Town of Tianjin coastal area as a typical soil salinization coastal area, the authors determined the correlation between main salt ions in the soil, carried out the random uniform thinning test for sampling points in the study area, and discussed the influence of different sampling densities on the interpolation results and the evaluation results of soil salinization. The results show that the farmland soil in Tianjin coastal area has mainly anions of Cl^-, and cations of Na⁺, and that the total Cl and Cl^- have good correlation with total salt in the soil. The authors extracted randomly a small number of samples to test total salt, and established an equation of total Cl and total salt, which could accurately calculate the total salt values for the whole samples. High-density sampling can improve the representation of the samples: when the sampling density is more than 4 points per square kilometers, the acceptance rate of the relative error is equal or greater than 80%; in addition, sampling density of evaluating salinization levels should not be less than 1 points per square kilometers.