黑河湿地土壤盐分特征及其对地下水埋深的响应规律

Soil Salinity Characteristics Analysis and Its Response to Groundwater Depth in Heihe Wetland

探讨张掖黑河湿地土壤盐分特征及其对地下水埋深响应的规律,是开展黑河流域水文、土壤及生态研究的重要基础。根据2014年—2018年研究区观测数据,辅助SPSS 24.0软件,应用描述统计、非参数检验、Spearman等级相关分析、回归分析等方法开展研究。结果表明:(1)随着地下水位埋深的增加,土壤全盐含量有先增加后降低的趋势,地下水位埋深小于60 cm时,土壤全盐表聚性特征明显。(2)离子浓度呈现:SO_(4)^(2-)>HCO_(3)^(-)>Ca^(2+)>Na^(+)>Cl^(-)>Mg^(2+)>K^(+)。(3)相关性分析表明,pH值、HCO_(3)^(-)、Cl^(-)、Ca^(2+)、Mg^(2+)与地下水位埋深之间呈现极显著相关性,SO_(4)^(2-)、Na^(+)、K^(+)与地下水位埋深之间不呈现相关性,但相关系数差异较大。(4)全盐含量与各离子之间存在较好的多元线性回归关系,判定系数R^(2)=0.987,回归方程F值=2135.9。

It is an important prerequisite to study the hydrology,soil and ecology of the Zhangye Heihe River Basin before exploring the characteristics of soil salinity and its response to groundwater depth.According to the observed data of the study area from 2014 to 2018,the SPSS 24.0 software was used to analyze the differences of total salt content and major salt ions in wetland soil in different soil layers by using descriptive statistics,non-parametric test,Spearman rank correlation analysis,regression analysis and other methods.The results are as follows.(1)With the increase of buried depth of groundwater level,soil total salt content increased first and then decreased.When the buried depth of groundwater level was within 60 cm,soil total salt content had obvious surface aggregation characteristics.(2)the ion concentration showed the characteristics of SO_(4)^(2-)HCO_(3)^(-)Ca^(2+)Na^(+)Cl^(-)Mg^(2+)K^(+).(3)The correlation analysis shows that pH,HCO_(3)^(-),Cl^(-),Ca^(2+),Mg^(2+)are highly significantly correlated with the buried depth of the groundwater level,while SO_(4)^(2-),Na^(+),K^(+)are not correlated with the buried depth of the groundwater level,but the correlation coefficients differ greatly.(4)There was a good multiple linear regression relationship between total salt content and each ion,R^(2)=0.987,F=2135.9.