潜水位气压效应的消除及消除效果评价

The Removal of Barometric Pressure Effects and Its Effectiveness Evaluation in an Unconfined Aquifer

地下水位的微动态变化主要受气压效应的影响,而能否有效地消除地下水位数据中的气压效应影响,对精确地获取含水层关键水文地质参数具有重要意义.基于四川省中江县垮梁子乡一处潜水含水层中的监测井,收集高精度、高频率的地下水位及大气压力监测数据,通过斜率法和Clark法确定气压效率,并利用线性回归法和反卷积回归法对监测井水位的气压效应进行消除,最终通过频谱分析法对消除结果进行评价,旨在找出适用于潜水位气压效应消除的方法.研究结果得出,由于考虑了水位变动的季节性趋势,Clark法获取的气压效率比斜率法更可靠;而反卷积回归法因为考虑了气压效应的时间滞后性,其对潜水位气压效应的消除效果优于线性回归法.

The micro-dynamic changes of the groundwater level are mainly influenced by the barometric pressure, and whether the barometric pressure effect on groundwater level data can be effectively removed is of great significance to accurately obtain key hydrogeological parameters of aquifers. In this paper, high-precision and high-frequency monitoring data for the groundwater level and the atmospheric pressure were collected based on monitored wells in an unconfined aquifer in Kualiangzi Town, Zhongjiang County, Sichuan Province. Barometric efficiency was determined by the slope and Clark methods and the barometric effects of water levels in monitored wells were removed using the linear regression and the inverse convolution regression. Finally, the elimination results were evaluated by means of the spectral analysis, with the aim of finding a method applicable to the removal of barometric effects at the water level. The results shown that the Clark method is more reliable than the slope method when considering seasonal trends in water level changes, and that the inverse convolution regression method is more effective than the linear regression method in removing the barometric effects in unconfined aquifers when considering the time lag of the barometric effect.