Post Vincent, Kooi Henk, Simmons Craig
Department of Hydrology and Geo-Environmental Science, Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
Ground Water. 2007 Nov-Dec;45(6):664-71. doi: 10.1111/j.1745-6584.2007.00339.x.
The use of hydraulic head measurements in ground water of variable density is considerably more complicated than for the case of constant-density ground water. A theoretical framework for dealing with these complications does exist in the current literature but suffers from a lack of awareness among many hydrogeologists. When corrections for density variations are ignored or not properly taken into account, misinterpretation of both ground water flow direction and magnitude may result. This paper summarizes the existing theoretical framework and provides practical guidelines for the interpretation of head measurements in variable-density ground water systems. It will be argued that, provided that the proper corrections are taken into account, fresh water heads can be used to analyze both horizontal and vertical flow components. To avoid potential confusion, it is recommended that the use of the so-called environmental water head, which was initially introduced to facilitate the analysis of vertical ground water flow, be abandoned in favor of properly computed fresh water head analyses. The presented methodology provides a framework for determining quantitatively when variable-density effects on ground water flow need to be taken into account or can be justifiably neglected. Therefore, we recommend that it should become part of all hydrogeologic analyses in which density effects are suspected to play a role.
在变密度地下水中使用水头测量比在常密度地下水中要复杂得多。当前文献中确实存在处理这些复杂情况的理论框架，但许多水文地质学家对此缺乏认识。当忽略或未正确考虑密度变化的校正时，可能会导致对地下水流向和流量大小的错误解释。本文总结了现有的理论框架，并为变密度地下水系统中水头测量的解释提供了实用指南。本文认为，只要考虑了适当的校正，淡水水头就可用于分析水平和垂直水流分量。为避免潜在的混淆，建议放弃使用最初为便于分析垂直地下水流而引入的所谓环境水头，而采用正确计算的淡水水头分析。所提出的方法提供了一个框架，用于定量确定何时需要考虑变密度对地下水流的影响，或何时可以合理地忽略这些影响。因此，我们建议它应成为所有怀疑密度效应起作用的水文地质分析的一部分。
