Unconfined Aquifers(非承压含水层)研究综述
Unconfined Aquifers 非承压含水层 - For all the studied catchments, during dry seasons without recharge, the depletion rate of groundwater is found to decrease with the decline in groundwater storage, which can be ascribed to the vertical heterogeneity of their unconfined aquifers. [1] Recharge mechanisms are: (1) river water seepage for the unconfined aquifers of the proximal and medial fan; (2) lateral flow for the confined aquifers of the medial and distal fan; and (3) precipitation infiltration for the phreatic water system. [2] Accordingly, in this study, an innovative numerical solution based on LBM was introduced to solve groundwater flow in unconfined aquifers, taking into account D2Q9 scheme. [3] The results show that rates of groundwater level decrease more than 1 m yr −1 in the confined and unconfined aquifers, with cumulative thicknesses of the compressible sediments between 160 and 170 m and Quaternary thicknesses between 400 and 500 m, yielding maximum hazard probabilities of 0. [4] Available data consist of groundwater level time series from 81 observation wells (2000-2018; 43 in confined aquifers, 15 in semi-confined aquifers and 23 in unconfined aquifers), total flow rates from 179 hydrometric stations (1960-2017), and meteorological data from a spatially interpolated 10 km x 10 km grid (1960-2017). [5] The results gained by Gibbs diagrams, bivariate plots, saturation index, and the major ions ratios demonstrated that minerals dissolution/precipitation, cation exchange, and human inputs play crucial roles in the unconfined aquifers. [6] The various sources of salinization, particularly in the unconfined aquifers, make it difficult to manage these resources. [7] These findings give important insight into mechanisms of CAS in a special setting of unconfined aquifers. [8] Ca; however, groundwater in deep, unconfined aquifers is characterized as HCO3-Ca. [9] Managed aquifer recharge (MAR) embeds techniques for purposefully increasing the recharge to confined or unconfined aquifers. [10] In unconfined aquifers it is well known that the drainage process is controlled by the unsaturated zone. [11] A key part of the project was quantifying the potential for a decline in the water quality of unconfined aquifers due to unintentional chemical release at the soil surface. [12] Urban centers radically alter hydrological cycles, causing unintended consequences for the environment, such as the creation of extensive contamination plumes in unconfined aquifers. [13] The unconfined aquifers in the Eastern Indo-Gangetic Plains (EIGP) of India are one of the most extensive aquifer systems in South Asia and are prone to ever intensifying agricultural systems. [14] This research estimates spatially and temporally the groundwater storage change and the storage coefficient in unconfined aquifers and under uncontrolled conditions by means of gravimetric data and validates the estimates by two procedures based on piezometric data. [15] Unconfined aquifers are exposed to seepage from the polluted drains. [16] Unconfined aquifers were more vulnerable to potability and palatability contamination. [17] The results contribute to the loss of contamination, based on the number of households with septic tanks and rudimentary cesspit, in unconfined aquifers, which were more vulnerable to contamination, mainly in peripheric expansions areas in the cities, where the deficit in sewage services tends to be high. [18] The results showed that the research area had a shallow groundwater level with groundwater flow relative to the south-southwest and composed of unconfined aquifers. [19] Both confined and unconfined aquifers were identified within the area, with four classes of aquifer proactive capacities as high, moderate, weak and poor. [20] These results indicated that all the model’s input variables have a significant effect on the groundwater level of unconfined aquifers, and confirmed the nature of the aquifers tapped within the present study sites. [21] For unconfined aquifers the hydraulic head is the same thing as the water table. [22] The response of unconfined aquifers to Earth's solid tides (Earth tides) has been used to study a number of hydrogeological, environmental, and ecological processes. [23] The results show there was a great potential for groundwater-unconfined aquifers. [24] The proposed geothermometer is exclusive to confined aquifer system and not applicable to unconfined aquifers. [25] Decreasing the aquifer hydraulic conductivity led to decrease in aquifer contamination, in which the confined aquifer pollution was less than the unconfined aquifers due to the clay cap, which plays a significant role in minimizing the solute transport into the groundwater reservoir, and to reduction of the aquifer salt variation by +19. [26] gov/dep/dsr/trends/ The source of the State’s water supply is either from surface waters (streams, rivers, and reservoirs) or from the ground (confined and unconfined aquifers). [27] 13% of confined aquifers showed higher fluoride than the permissible limit but 100% unconfined aquifers (dug wells) have a low level of fluoride concentration, i. [28] Based on laboratory analysis, the groundwater types in the dug wells (unconfined aquifers) were dominated by type Ca 2+ -Na + -HCO 3 -. [29] Another apposite example is the exhaustive analysis of the Dupuit–Forchheimer approximation to the flow equations for unconfined aquifers, Sections 4. [30] The higher confining degree has been observed in those areas of higher subsidence signatures, implying that the subsidence potential in confined aquifers is higher than that of unconfined aquifers. [31] By appointing numerical modeling as the reference method, a comparison between different methods showed that a semi-analytical method best fits the reference WHPA, and that analytical solutions produced overestimated WHPAs in unconfined aquifers as regional groundwater flow characteristics were neglected. [32] Annual groundwater withdrawals compiled by county 2 Confined and Unconfined Aquifers in Quaternary Sediments in the Glaciated Conterminous United States range on an areal basis from less than 1 to 370 millimeters per year, and the mean is 7. [33] The findings from this study are useful for increasing the prediction accuracy of GW level variations in unconfined aquifers for sustainable GW resource management. [34] This is the first time that confined and unconfined aquifers have been compared using data-driven models. [35] An analytical model of the hydraulic head due to oscillatory pumping in unconfined aquifers is presented. [36] Hydraulic connections between the unconfined and confined aquifers, the vulnerability of unconfined aquifers, and the properties of confined aquifers were explicitly considered in this method. [37] Lithologic, geo-electric, and gamma ray logs revealed the occurrence of confined/semi-confined and unconfined aquifers/semi-unconfined which correspond to lower and upper sands, respectively. [38] These data not only allow a better understanding of the spatial distribution of recharge rates in unconfined aquifers, but also are used to develop strategies for the rational and integrated use of surface water and groundwater. [39] Studies investigating the effects of inland recharge on coastal groundwater dynamics were carried out typically in unconfined aquifers, with few in confined aquifers. [40] The groundwater recharge produced by discrete precipitation events in unconfined aquifers is often estimated from water-table fluctuations (WTFs) recorded in shallow wells. [41] Steady state and transient analytical solutions, respectively describing the drawdown as a function of the distance from the well (r), or of r and time, are provided for confined, leaky and unconfined aquifers. [42]对于所有研究的集水区，在没有补给的旱季，发现地下水的消耗率随着地下水储量的下降而降低，这可以归因于其非承压含水层的垂直异质性。 [1] 补给机制为： (1) 近、中扇非承压含水层河水渗流； (2) 中远扇承压含水层侧向流动； (3) 潜水系统的降水入渗。 [2] 因此，在本研究中，在考虑 D2Q9 方案的情况下，引入了一种基于 LBM 的创新数值解法来求解无承压含水层中的地下水流动。 [3] 结果表明，承压含水层和非承压含水层地下水位下降幅度均超过 1 m yr -1，可压缩沉积物累积厚度在 160 到 170 m 之间，第四纪厚度在 400 到 500 m 之间，最大危害概率为 0 . [4] 可用数据包括来自 81 个观测井的地下水位时间序列（2000-2018 年；承压含水层 43 个，半承压含水层 15 个，非承压含水层 23 个）、179 个水文测量站的总流量（1960-2017 年）和气象来自空间插值 10 km x 10 km grid (1960-2017) 的数据。 [5] 通过吉布斯图、双变量图、饱和指数和主要离子比率获得的结果表明，矿物溶解/沉淀、阳离子交换和人类输入在非承压含水层中起着至关重要的作用。 [6] 盐渍化的各种来源，特别是在非承压含水层中，使得管理这些资源变得困难。 [7] 这些发现为了解非承压含水层特殊环境中的 CAS 机制提供了重要的见解。 [8] 钙；然而，深层无承压含水层中的地下水以 HCO3-Ca 为特征。 [9] 管理含水层补给 (MAR) 嵌入了有目的地增加承压或非承压含水层补给的技术。 [10] 在非承压含水层中，排水过程由非饱和带控制是众所周知的。 [11] 该项目的一个关键部分是量化非承压含水层水质下降的可能性，因为土壤表面的化学物质无意释放。 [12] 城市中心从根本上改变了水文循环，对环境造成了意想不到的后果，例如在非承压含水层中产生了广泛的污染羽流。 [13] 印度东部印度恒河平原 (EIGP) 的无承压含水层是南亚最广泛的含水层系统之一，并且容易出现日益集约化的农业系统。 [14] 本研究通过重力数据在空间和时间上估计非承压含水层和非受控条件下的地下水储量变化和储量系数，并通过基于测压数据的两个程序验证估计值。 [15] 非承压含水层暴露于受污染的排水沟的渗漏。 [16] 非承压含水层更容易受到饮用和适口性污染的影响。 [17] 根据拥有化粪池和简陋污水坑的家庭数量，这些结果有助于污染的损失，这些无承压含水层更容易受到污染，主要是在城市的外围扩张区域，那里的污水服务不足往往会导致要高。 [18] 结果表明，研究区地下水位较浅，地下水流向南西南偏南，由非承压含水层组成。 [19] 该区域内确定了承压含水层和非承压含水层，含水层主动能力分为高、中、弱和差四类。 [20] 这些结果表明，所有模型的输入变量对非承压含水层的地下水位都有显着影响，并证实了本研究地点内开采的含水层的性质。 [21] 对于非承压含水层，水头与地下水位相同。 [22] 非承压含水层对地球固体潮汐（地球潮汐）的响应已被用于研究许多水文地质、环境和生态过程。 [23] 结果表明，地下水无承压含水层具有巨大潜力。 [24] 所提议的地温计专用于承压含水层系统，不适用于非承压含水层。 [25] 含水层导水率的降低导致含水层污染减少，其中承压含水层的污染低于非承压含水层，由于粘土盖层，这在最大限度地减少溶质向地下水储层的输送方面发挥了重要作用，并减少了含水层的污染。含水层盐分变化 +19。 [26] gov/dep/dsr/trends/ 该州的供水来源要么来自地表水（溪流、河流和水库），要么来自地面（承压和非承压含水层）。 [27] 13% 的承压含水层的氟化物含量高于允许限值，但 100% 的非承压含水层（挖井）的氟化物浓度较低，即。 [28] 根据实验室分析，所挖井（非承压含水层）的地下水类型以Ca 2+ -Na + -HCO 3 - 类型为主。 [29] 另一个恰当的例子是对无承压含水层流动方程的 Dupuit-Forchheimer 近似的详尽分析，第 4 节。 [30] 在沉降特征较高的区域观察到较高的承压程度，这意味着承压含水层的沉降潜力高于非承压含水层的沉降潜力。 [31] 通过指定数值模拟作为参考方法，不同方法之间的比较表明，半解析方法最适合参考WHPA，并且由于区域地下水流动特征被忽略，解析解导致高估无承压含水层的WHPA。 [32] 美国冰川地区第四纪沉积物中第 2 郡承压和非承压含水层编制的年度地下水抽取量按面积计算，范围为每年不到 1 至 370 毫米，平均值为 7。 [33] 本研究的结果有助于提高无承压含水层中 GW 水平变化的预测准确性，从而实现可持续的 GW 资源管理。 [34] 这是首次使用数据驱动模型比较承压含水层和非承压含水层。 [35] 液压头的分析模型 由于在非承压含水层中的振荡抽水。 [36] 该方法明确考虑了非承压含水层和承压含水层之间的水力联系、非承压含水层的脆弱性以及承压含水层的特性。 [37] 岩性、地电和伽马射线测井揭示了承压/半承压和非承压含水层/半非承压含水层的出现，分别对应于下砂层和上砂层。 [38] 这些数据不仅可以更好地了解非承压含水层补给率的空间分布，还可以用于制定合理和综合利用地表水和地下水的战略。 [39] 调查内陆补给对沿海地下水动态影响的研究通常在非承压含水层中进行，在承压含水层中很少。 [40] 非承压含水层中离散降水事件产生的地下水补给通常根据浅井中记录的地下水位波动 (WTF) 进行估算。 [41] 为承压、渗漏和非承压含水层提供了稳态和瞬态分析解，分别将下降描述为距井距离 (r) 或 r 和时间的函数。 [42]
Shallow Unconfined Aquifers 浅层非承压含水层
The vadose-phreatic zone boundary in the shallow unconfined aquifers fluctuation in response to seasonal recharge patterns. [1] When used jointly, the two approaches reveal that the shallow unconfined aquifers that require increased groundwater protection account for approximately 5% of the territory. [2] This paper concerns the simulation of the water table elevation in shallow unconfined aquifers where infiltration is assumed as the main mechanism of recharge. [3] The linear recession model has been widely used by baseflow recession analysis for reason of simplicity and convenience, but recent studies show that nonlinear recession models fit well, and the relationship between the reservoir storage of shallow unconfined aquifers and the groundwater discharge was to be identified as nonlinear in the literature based on the analysis of numerous streamflow recession curves. [4] In this work, we present a class of new efficient models for water flow in shallow unconfined aquifers, giving an alternative to the classical but less tractable 3D-Richards model. [5] In most basins, however, rainwater also finds its way through macropores and preferential pathways to the shallow unconfined aquifers within hours of falling. [6]浅层非承压含水层中渗流-潜水带边界响应季节性补给模式的波动。 [1] 当联合使用时，这两种方法表明需要加强地下水保护的浅层无承压含水层约占领土的 5%。 [2] 本文关注浅层非承压含水层中地下水位升高的模拟，其中假设渗透是补给的主要机制。 [3] 线性衰退模型由于简单方便而被广泛用于基流衰退分析，但最近的研究表明非线性衰退模型拟合良好，浅层非承压含水层的水库蓄水量与地下水排放之间的关系被确定为文献中的非线性基于对众多径流衰退曲线的分析。 [4] 在这项工作中，我们提出了一类新的有效模型，用于浅层无承压含水层中的水流，为经典但不太容易处理的 3D-Richards 模型提供了替代方案。 [5] 然而，在大多数盆地中，雨水也会在下落数小时内通过大孔隙和优先通道到达浅层无承压含水层。 [6]
Coastal Unconfined Aquifers
Based on numerical simulations considering variably saturated, density-dependent pore-water flow and salt transport, this study examines the combined effects of evaporation and ocean surge inundation on soil salinization in coastal unconfined aquifers. [1] In the present study, the salt-water up coning problem in coastal unconfined aquifers is investigated. [2] Tides and seasonally varying inland freshwater input, with different fluctuation periods, are important factors affecting flow and salt transport in coastal unconfined aquifers. [3]基于考虑可变饱和、密度依赖的孔隙水流动和盐分输送的数值模拟，本研究检验了蒸发和海潮淹没对沿海非承压含水层土壤盐渍化的综合影响。 [1] 在本研究中，研究了沿海非承压含水层的咸水上升锥进问题。 [2] 潮汐和季节性变化的内陆淡水输入，具有不同的波动周期，是影响沿海非承压含水层流量和盐分输送的重要因素。 [3]
Deep Unconfined Aquifers 深层非承压含水层
For this purpose, a large data set of the groundwater quality parameters (for a period of 2005–2016) was obtained from the deep unconfined aquifers. [1] For this purpose, a large data set of the groundwater quality parameters (for a period of 2005–2016) was obtained from the deep unconfined aquifers. [2]为此，从深层无承压含水层中获得了大量的地下水质量参数数据集（2005-2016 年期间）。 [1] 为此，从深层无承压含水层中获得了大量的地下水质量参数数据集（2005-2016 年期间）。 [2]