青铜峡灌区地下水电导率时间稳定性及变化特征分析

Analysis of time stability and variation characteristics of groundwater conductivity in Qingtongxia Irrigation area

土壤盐渍化是制约青铜峡灌区社会经济发展的主要因素之一。通过青铜峡灌区地下水电导率的时间稳定性及变化特征分析,快速有效地预测地下水电导率变化,对指导灌区农业生产具有重要意义。基于青铜峡灌区36眼监测井在19个时间点的监测资料,利用相对差分法和Spearman秩相关系数法分析地下水电导率的时间稳定性特征,为降低土壤盐渍化风险提供参考。分析结果表明:青铜峡灌区地下水多为微含盐水和中含盐水,地下水电导率均为中等变异,变异系数区间为62%~67%。在整个监测周期内,地下水电导率均未出现明显的增大趋势,表明该区地下水水质较为稳定。电导率值越大其变化也越大。地下水电导率呈现出明显的时空稳定性,其代表性位置点为27^(#)监测井。该区地下水平均电导率与27^(#)监测井所预测的地下水电导率的残差平方和仅为0.008,基本代表了该区地下水电导率的变化规律,通过该点可快速有效地预测该区地下水电导率的变化,进而为降低土壤盐渍化风险提供科学依据。

Soil salinization is one of the main factors restricting the social and economic development in Qingtongxia irrigation area.Based on the analysis of the time stability and change characteristics of groundwater conductivity in Qingtongxia irrigation area,it is of great significance to predict the change of groundwater conductivity quickly and effectively.Based on the monitoring data of 36 Wells at 19 time points in Qingtongxia irrigation District,the relative difference method and Spearman rank correlation coefficient method were used to analyze the temporal stability characteristics of groundwater conductivity,which provided a reference for reducing the risk of soil salinization.The results show that the groundwater in Qingtongxia irrigation area is mostly brackish water and medium brackish water,and the electrical conductivity of the groundwater varies moderately,with the coefficient of variation ranging from 62%to 67%.In the whole monitoring period,the groundwater conductivity did not show an obvious increasing trend,indicating that the groundwater quality in this area is relatively stable.The greater the conductivity value,the greater the change.The groundwater conductivity shows obvious spatiotemporal stability,and its representative location is 27^(#)monitoring well.The residual sum of squares between the average groundwater conductivity in this area and the groundwater conductivity predicted by the 27^(#)monitoring well is only 0.008,which basically represents the change law of groundwater conductivity in this area.This point can be used to quickly and effectively predict the change of groundwater conductivity in this area,thus providing a scientific basis for reducing the risk of soil salinization.