青海西宁盆地盐渍土盐分空间动态分布特征分析

The analysis of dynamic spatial distribution characteristic of saline soil salinity in Xining basin,Qinghai

为了分析工程建设层盐渍土地基盐分空间动态分布特征,将青海西宁盆地盐渍土分布区沿高程降低方向划分为5个亚区,进行3 m以内的土样采集和室内测试,并利用Excel等软件处理数据。结果表明：研究区盐渍土主要为中性盐渍土,p H值随垂向深度增加而降低,自西向东沿高程降低的动态变化。全盐量具有在垂直方向上集中两层分布,在水平方向上自西向东基本降低的特点,在地表0 m处基本上呈现出一个低值现象。盐分主要积累在两个深度层,其中,0.2-0.6 m和1.4-1.7 m处,全盐量分别在820-15 510 mg/kg和1 490-9 690 mg/kg。盐渍土类型在垂向随取样深度变化可以分为3层,即第一层以硫酸盐渍土为主（0-1.0 m）;第二层以亚硫酸盐渍土为主（1.0-1.7 m）;第三层为硫酸盐渍土（1.7-3.0 m）。研究区盐渍土中全盐量及主要组份主要受SO4^2-和Ca^2＋控制,并且沿高程降低,逐步呈现由SO4^2-和Ca^2＋控制变为由SO4^2-和Na^＋控制的规律。

In order to analyze the saline soil foundation salinity dynamic spatial distribution characteristics of engineering construction stratum,the saline soil distribution area in Xining basin of Qinghai was partitioned into five sub- regions along the direction of descending elevation. Soil samples within 3 m depth of each zone were collected and measured in laboratory. The data were processed by using Excel and other software. The saline soil is mainly neutral soil in the study area. The p H decreases with the vertical depth,presenting a decreasing trend with the elevation from west to east.Total salt content is centralized in two layers in the vertical direction,but substantially reduced in the horizontal direction from west to east,exhibiting substantial low values at the surface（ 0 m）.Salt salinity is mainly accumulated in two layers with total salt content 820 - 15 510 mg / kg and1490 - 9 690 mg / kg respectively at 0. 2 - 0. 6 m and 1. 4 - 1. 7 m. The saline soil types in the vertical direction can be divided into three layers with the sampling depth,namely,the first layer is mainly sulfate saline soil（ 0 - 1. 0 m）; the second layer is mainly sulfurous saline soil（ 1. 0 - 1. 7m）; the third layer is the sulfate saline soil（ 1. 7 - 3. 0 m）. The total salt content and the main component of the saline soil in the study area are mainly controlled by SO4^2- and Ca^2＋,decreasing with elevation. The composition changes gradually from SO4^2- and Ca^2＋to SO4^2- and Na＋.