基于灰色关联分析的土壤水盐动态变化研究

根据洛惠渠灌区多年观测资料与实地调查,采用灰色关联法对灌区地下水矿化度、埋深与土壤含盐量的动态关系进行了分析。阐明了3者之间的年际动态变化规律和耦合关系,建立了灌区土壤水盐动态耦合关系模型。结果表明,地下水矿化度是影响土壤含盐量的主要因素,地下水埋深对盐分的转移也起着重要的作用,各因子之间相互作用,形成了复杂条件下的耦合关系;该灌区处于脱盐和相对稳定状态,受外界因素影响,土壤含盐量变化趋势与地下水矿化度和地下水位变化趋势不一致;基于地下水矿化度和地下水埋深的土壤水盐耦合关系模型具有较高的预测精度,能够很好地定量描述土壤水盐动态变化与其影响因子之间的响应关系。

Investigation on Soil Water--Salt Dynamics Based on Grey Correlation Analysis

Based on field-observed data from Luohui Irrigation District,grey correlation analysis method was applied to analyze the relations between groundwater mineralization,depth and soil salt content.The model of soil water—salt dynamics was then established based on the analysis.The results show that groundwater mineralization was the main factor affecting soil salt contents,and also played an important role in transferring salts.The interaction among various factors formed coupling relationship under the complicated condition.As affected by external factors,it can be preliminarily determined that the soil of the Irrigation District was in desalination condition and in a relative stable state.The variation tendency of soil salt content differed from those of groundwater mineralization and groundwater depth.The quantitative model established in this study described well the response of groundwater dynamic to various factors with sufficient high accuracy.The combination provides a feasible method for analyzing the mechanism of soil water—salt dynamics under the condition of shallow groundwater during the crop growing season.