井水位对气压响应的滞后及其机理

通过井口空气压力变化对井水位影响的试验，分析了井水位对空气压力变化响应幅变和滞后时间，认为在相同的井口空气压差情况下，压力变化周期越大，井水位响应幅度也越大，而位相滞后越小。水平层状承压含水层的理论研究表明，井水位对气压影响的滞后时间主要取决于含水层的导水系数和气压变化的周期，这两种参数越大，则滞后时间越小。因此，井水位对气压响应的滞后是由于水压井孔与含水层间渗流需要一定时间造成的，而不是由于地面     

承压井水位对地表水潮汐的响应

本文以地表水潮汐影响承压井水位的偏微分方程为基础,考虑到井孔和含水层之间相互渗流的边界条件,得出方程的解。通过对解中水井含水层参数给予一些可能的值进行数值计算,绘出了承压井水位地表潮汐荷载效率与位相滞后曲线,讨论了这个效率和位相滞后水井含水层参数之间的关系。认为这个效率主要取决于含水层的孔隙度和固体骨架压缩系数;孔隙度愈小,压缩系数愈大,则效率也愈大。而位相滞后主要取决于含水层的渗透系数和厚度;这两个参数越大,则位相滞后越小。 本文还介绍了上海地区地下水位与地表水潮汐的观测结果。把这些观测结果和本文理论结果比较分析,两者符合得较好。     

井水位的“记忆”滞后效应

观测资料表明,井水位对信息响应存在的“记忆”滞后现象,它与一般的位相滞后不同,在鲁２９井现场试验也证明了井水位对井吕空气压力变化的响应存在的“记忆”滞后现象。利用水平层状承压含水层模式,从理论上解释了井水位对井口空气压力变化响应“记忆”滞后现象,认为这种现象与水井含水层的导水系数有关,含水层导不系数越小,这种现象越明显,用一般多元回归方法无法较好地扣除井水位中“记忆”滞后影响,作给出了一种可以扣     

水井潮汐观测资料的分析

对全国地下水观测网中33口井孔的水位和气压观测资料,采用反复调和分析的方法,求出了井水位固体潮体应变各分波群的潮汐系数和位相滞后,求出了井水位气压各分波群的气压系数和位相滞后。对这些结果作了初步分析和讨论。     

由承压井水位动态反演水井含水层的应力变化

分析了承压井含水层应力场与地壳应力应变之间以及含水层应力应变与井水位之间的定量关系,给出了利用承压不位变化反演含水层应力变化的三种新方法,通过含水层的参数,固体潮效应以及气压效应反演水井含水层的应力变化,讨论了承压井水位反映含水层应力应变的稳定性,并将该反演结果与其它方法的结果进行了比较。     

深井水位的固体潮效应

本文从体应变固体潮对深井水位影响的偏微分方程出发,考虑到含水层和井孔之间相互渗流的边界条件,用叠加原理、冲量定理和分离变量法等方法得出了方程的解.通过对这个解中水井含水层参数给予一些可能的值进行数值计算,讨论了水井固体潮系数和位相滞后与水井含水层参数间的关系,较好地解释了井水位对固体潮响应的位相滞后现象.计算表明,井孔的半径、含水层的孔隙度及固体骨架的体压缩系数愈大,含水的导水系数愈小,则水井水位的固体潮系数愈小,而水位对固体潮响应的位相滞后愈大.井水对长周期的潮汐响应比对短周期的更好.      

中国地下水潮汐的观测研究和分析

本文简单介绍了中国地下水潮汐的观测研究情况,介绍了对承压水位潮汐机理研究的理论结果,给出了固体潮体应变、气压和海洋潮汐对承压水头影响的偏微分方程,从这些方程的简化解讨论了它们与含水层参数间的关系.并从全国选取了33口有代表性的井孔,对这些井孔的水位和气压观测资料采取反复调和分析的方法,求出了它们的水位固体潮体应变各分波的潮汐系数和位相滞后,也求出了水位气压各分波的系数和位相滞后.      

地下水潮汐现象的物理机制和统一数学方程

用新的分层承压含水层模式 ,不但考虑含水层的力学压缩性质 ,而且考虑含水层的渗流特性 ,并结合扰动信息源的频率特性 ,分别研究扰动源地球固体潮、大气潮和地表负荷潮对承压井水位和流量的影响机理 ,给出相应的偏微分方程。从方程的解释或数值解讨论扰动源与承压井含水层的力学压缩参数、渗流特性参数及与频率特性频数的关系 ,进而给出承压井水位和流量对地球固体潮、大气潮和地表负荷潮汐响应的统一数学方程及其潮汐响应函数 ,并揭示了上述几类潮汐扰动信息源对承压井水位和流量影响的物理机理     

鲁29井井口变压试验

本文介绍了鲁29井井口变压试验结果。试验结果表明,井水位对井口空气压力变化的响应与变化周期有关。井口空气压力变化的周期越大,则井水位的响应幅度越大,而响应的位相滞后越小。对于长周期压力变化的响应,在量值上为井口压力每hPa变化引起水位10.2mm的变化。由于水在井孔与含水层之间的渗流造成了井水位对空气压力变化的响应产生位相滞后。这些试验结果与实际观测资料分析的结果及理论模型研究的结果是一致的。     

深井水位对固体潮和气压的响应

本文以体应变固体潮对深井水位影响的偏微分方程为基础，考虑到含水层与井孔之间相互渗流的边界条件，用叠加原理、冲量定理的分离变量等方法得出了方程的解。把水井含水层的参量给予一些可能的值，通过数值计算讨论了水井固体潮系数、位相滞后和含水层参数之间的关系，解释了井水位对固体潮响应的位相滞后现象。结果表明，井孔的半径、含水层的孔隙度及固体骨架的体压缩系数愈大，含水层的导水系数愈小，则水井水位的固体潮系数愈小     

Identifying Aquifer Type in Fractured Rock Aquifers using Harmonic Analysis

Determining aquifer type, unconfined, semi‐confined, or confined, by drilling or performing pumping tests has inherent problems (i.e., cost and complex field issues) while sometimes yielding inconclusive results. An improved method to cost‐effectively determine aquifer type would be beneficial for hydraulic mapping of complex aquifer systems like fractured rock aquifers. Earth tides are known to influence water levels in wells penetrating confined aquifers or unconfined thick, low‐porosity aquifers. Water‐level fluctuations in wells tapping confined and unconfined aquifers are also influenced by changes in barometric pressure. Harmonic analyses of water‐level fluctuations of a thick (～1000 m) carbonate aquifer located in south‐central Oklahoma (Arbuckle‐Simpson aquifer) were utilized in nine wells to identify aquifer type by evaluating the influence of earth tides and barometric‐pressure variations using signal identification. On the basis of the results, portions of the aquifer responded hydraulically as each type of aquifer even though there was no significant variation in lithostratigraphy. The aquifer type was depth dependent with confined conditions becoming more prevalent with depth. The results demonstrate that harmonic analysis is an accurate and low‐cost method to determine aquifer type.     

A new theoretical solution of the effect of atmospheric pressure on water level

Based on the partial differential equation governing the effect of atmospheric pressure on water level of confined well, deriving the boundary condition and considering the seepage water between well and aquifer, the author obtained the analytical solution of water level change in time domain under the action of an atmospheric pressure history with the Laplace transform method. This solution is composed of two terms:stable and retarded terms. The stable term is the multiplication of barometric efficiency and simultaneous atmospheric pressure, and it implies the value of water level after infinite time when the atmospheric pressure is a constant from the time in question. The retarded term is the transient process due to the time lag of water exchange between well and aquifer. From the solution, it is obtained that the interference of atmospheric pressure on water level is the integral superimposition of the contribution of all atmospheric pressure changes before the time in question. So that, we further found out the response function of pulsive atmospheric pressure history. Calculation shows: (1) The pulsive response function starts from zero and tends to a steady value, which is proportional to the barometric efficiency, when the time tends to infinity; (2) The retarded time depends on the mechanical property of aquifer and the radius of well. The larger the seepage coefficient, the smaller the radius of well and the thicker the aquifer, then the shorter the retarded time gets. This solution can be used as the theoretical basis for further analysis of the atmospheric effect and practical correcting method in the future.     

华蓥山地区4口井水位潮汐动态特征研究

本文选择沿华蓥山断裂带分布的荣昌等4口观测井,利用Baytap-G潮汐分析方法,计算各井水位和气压及理论固体潮的潮汐振幅谱,比较其潮汐频谱差异,通过对主要潮汐分波振幅的回归计算定量分析各井水位受气压潮和固体潮影响的大小。基于对井水位正常动态的认识,选择各井水位潮汐的主要分波,对井水位长时序数据进行分析计算,提取水位潮汐响应特征参数(振幅比和相位差),进而探讨特征参数动态变化特征。最后对井水位受气压潮和固体潮影响的差异原因进行了初步探讨。结果表明,荣昌井水位主要受气压作用的影响,北碚、大足、南溪三口井水位受固体潮-气压潮综合作用的影响,而荣昌井水位只受气压潮影响可能与该井所处含水层裂隙发育且该井未下设止水套管有关;荣昌井P_1S_1K_1波和南溪井M_2波振幅比和相位差在几次大震后没有明显变化,说明地震波没有使井孔与含水层之间的水流交换发生显著变化,而北碚井和大足井M_2波振幅比和相位差分别在汶川和芦山地震时发生变化,反映了地震波的疏通影响。     

井-含水层系统地下水类型定量分析和判别

利用水位、 气压和理论固体潮数据, 采用卷积回归法中水位对气压的阶跃响应函数, 定量地分析和判定了华北北部板桥井、 大灰厂井、 黄骅井、 大甸子井、 丰镇井和三号地井的井-含水层系统的地下水类型, 并结合研究时段内各井的气压系数和M₂波潮汐因子的结果进行了对比分析． 结果表明: ① 各井的滞后时间与阶跃响应函数之间存在明显的以e为底的指数函数关系, 且底数e的系数的正负决定了井-含水层系统的地下水类型; ② 承压井的阶跃响应函数随滞后时间的增大而增大, 且最佳阶跃响应函数值越大, 相应的气压系数和M₂波潮汐因子也越大, 反之亦然; ③ 潜水井和半承压水井的阶跃响应函数随滞后时间的增大而减小, 其最佳阶跃响应函数与气压系数和M₂波潮汐因子间的关系不明显, 可能与含水层的水力特性、 井孔结构及固体潮汐波的频率有关．      

New Insights from Well Responses to Fluctuations in Barometric Pressure

Hydrologists have long recognized that changes in barometric pressure can produce changes in water levels in wells. The barometric response function (BRF) has proven to be an effective means to characterize this relationship; we show here how it can also be utilized to glean valuable insights into semi‐confined aquifer systems. The form of the BRF indicates the degree of aquifer confinement, while a comparison of BRFs between wells sheds light on hydrostratigraphic continuity. A new approach for estimating hydraulic properties of aquitards from BRFs has been developed and verified. The BRF is not an invariant characteristic of a well; in unconfined or semi‐confined aquifers, it can change with conditions in the vadose zone. Field data from a long‐term research site demonstrate the hydrostratigraphic insights that can be gained from monitoring water levels and barometric pressure. Such insights should be of value for a wide range of practical applications.     

鲁03井水位滞后于气压的处理

本文给出了一种处理井水位对气压影响滞后的方法,同时给出了计算公式。以鲁03井为例,用这种方法求出其井水位气压系数为6.41mm/hpa,水位对气压响应的滞后时间为1.52小时。该方法排除气压影响的效果较好,水位的气压校正中误差明显减小。     

井水位的固体潮效应和气压效应与含水层参数间的定量关系

本文分析了水井水位的固体潮效应和气压效应与承压含水层参数之间的定量关系。结果表明,含水层的固体骨架体积压缩系数和孔隙度越小,水井水位的固体潮系数则越大;含水层的固体骨架的体积压缩系数越小,孔隙度越大,則水井水位的气压效率越大。本文还把理论结果和固体潮及气压的实际观测结果进行了对比,两者符合得较好。