洛阳CK7井水氡资料动态特征及影响因素分析

对洛阳CK7井水氡观测资料动态特征以及与地下水水位、区域降雨量、伊河水水位流量的相关性进行分析,以此评估降雨量、伊河水水位流量对洛阳台地下水观测的影响,分析显示降雨、河水水位流量与地下水位具有相关性,对观测水氡的影响不明显。     

河北井网水位观测中的刚性动态与弹性动态

在经典的水文地质学专著中,有这样两句话:“地下水动态是地下水均衡的外部表现;地下水均衡是导致动态变化的内在原因”。也就是说,水位变化反映着含水层内水量的均衡。属于正均衡,水位上升;属于负均衡,水位下降。这一观点,在很长时期内成为研究地下水动态的基本指导思想。无疑:这在研究浅层地下水资源评价中是正确的。尽管在邢台地震后广大地震工作者观测到一些与含水层水量变化毫不相干的水位动态,但由于理论准备不足,对那些动态的意义和价值认识不够,未引起足够的重视和深入的研究。全国第二代地震地下水观测网的建设和大量观测资料的取得,为研究地下水动态提供了新鲜的思路与途径,推动着地震地下水工作的飞速发展。在1981年国家地震局组织的地下水影响因素研究组的研究成果《地震地下水动态及其影响因素》专著中首     

气温、气压、地下水理论固体潮对新04井静水位的影响分析

以新04井静水位为研究对象,分析气温、气压和地下水理论固体潮对新04井静水位的影响特征,并探讨其机理.结果表明:① 气温、气压对新04井静水位长趋势变化和短周期变化影响均比较大,而地下水固体潮对新04井静水位变化影响很小;② 气温是静水位年变化最主要的影响因素,表现为中高度线性负相关,参与计算的2段观测数据中,2007...     

福建永安井水位大幅度异常变化原因的研究

2001年7月18日起,永安井水位出现持续的大幅度上升变化。经调查落实,这是由于该井附近的另一口多年开采的井孔,于2001年7月17日突然停止抽水,从而使永安井的地下水补给量增大,造成水位大幅度上升。深入分析该井水位变化的成因,为研究邻井抽水对地震地下水动态观测井水位动态的影响提供了一个实例,对于识别地下水前兆异常与抽水干扰有一定的参考意义。     

井水位同震响应特征与机理研究进展

大地震会在很大的范围内引起地下水响应,研究地震如何影响地下水流动的物理过程有助于认识地震和水之间的相互作用。震后井水位的变化比较直观地反映了地下水变化,而且观测的数据相对比较多。同震井水位的变化主要有3种类型：阶跃变化、持续性变化和水位随地震波的震荡。引起同震井水位变化的机制有很多,即使同样的水位变化,其对应的机制也可...     

大同6.1级地震前后河北省地下水位前兆异常分析

识别地下水动态地震前兆异常,必须根据观测井地质及水文地质条件,分析地下水的多年动态特征,影响水位的干扰因素及异常变化与地震活动的关系。本文通过上述分析,认为大同6.1级地震前,河北省地下水网中万全、雄县、完县三口井存在水位异常变化。     

广西北流—广东化州MS 5.2级地震前后阳江新洲深部地热关联地下水异常研究

介绍了广东阳江新洲地热田深部地下水关联井水显著异常,广西北流—广东化州M_S5.2级地震发震前,新洲地热田监测井中两次延续数十小时的水位上涌现象,该现象解析是由于地热田东西向断层被挤压,引起深部地下水上升受阻而向地热田周边浅层地下水排泄,最终导致监测井中水位上涨。这意味着新洲地热田浅层地下水受深部地下水的影响,这种地下水体系对地应力活动引起的应变更敏感。研究结果对地震先兆、深部水文、深部地热均有参考意义。     

基于地震背景噪声监测山东临沂地区地下水位变化

选取山东省临沂地区的JUN与JUX台站数据资料,运用背景噪声互相关技术计算了2009年1月1日—2011年1月1日台站对间的互相关函数,利用移动窗互谱法计算相对速度变化,并分析其与莒县气象观测站记录的降水和莒南鲁14号井记录的地下水水位变化的关联性。研究结果表明,区域降水呈季节性变化,夏季降水量大,冬季降水量小;地下水水位呈季节性变化,初夏季水位较低,随后水位值逐渐增加,初冬季水位较高,随后水位值逐渐减少;地下介质速度变化亦具有季节性特征,变化幅度约为±0.2%,与水位变化呈一定的负相关趋势,即夏季水位增加、相对速度变化降低,冬季水位减少、相对速度变化升高。     

井水位气压系数的探讨

井孔水位气压系数是表征井孔水位气压效应以及井孔水位对应力应变反映灵敏程度的重要指标。本文以我国地震地下水观测井网提供的素材为基础,运用统计方法详细分析了影响井孔水位气压系数的因素,重点讨论了对同一井孔而言,气压系数是常数还是变量这个有争议的问题,并通过分析得出了气压系数是变量的结论。本文结论对合理选择地震地下水观测井及从水位观测值中消除气压的影响将是有益的。     

体膨胀固体潮对水井水位观测的影响

本文用地下水动力学原理建立了体膨胀固体潮对水井水位影响的方程。经过对此方程的简化求解后,讨论了水位体膨胀固体潮效应的影响因素,得出了在特定条件下的水井水位体膨胀固体潮系数。     

识别地下水超采区井水位异常性质的理论与方法

长期过量开采地下水,使地下水位持续下降、水质发生变化,动水位观测井断流;地面沉降造成井管上窜,观测管路系统被损坏等,这些现象对地震地下流体观测地震前兆异常的正确判断带来很大困难。应用水文地质理论与方法,分析含水层的水均衡状态、应力-应变状态及其与水位动态的关系,初步探讨了超采区井水位异常性质的理论与方法。结果表明,根据井孔所在区水位下降漏斗的扩散特征,结合以上所提到的理论和方法,依据资料多年变化特征,可以较准确地判断异常的性质。研究结果有助于区分单一集中抽水与长期地下水超采对水位观测的影响,有助于正确识别超采区水位前兆异常,有助于地震分析预报水平的提高     

Theory and Method for Identifying Well Water Level Anomalies in a Groundwater Overdraft Area

The overexploitation of underground water leads to the continuous drawdown of groundwater levels, change of water quality and dry-up in dynamic water level observation wells. Due to land subsidence, the well pipes uplift and the observation piping systems are damaged. These environmental geology problems can present serious difficulties for the identification of earthquake anomalies by groundwater level observation. Basied on hydrogeological theories and methods, the paper analyzes the relations of the water balance state of aquifers with stress-strain conditions and the water level regime, and then discusses preliminarily the theory and method for identifying well water level anomalies in a groundwater overdraft area. The result shows that we can accurately judge the nature of the anomaly according to the diffusion character of the drawdown funnel in the well area in combination with the aforementioned theory and method and multi-year variation patterns obtained from existing data. The results of the research are helpful for distinguishing the influence of single centralized water pumping from the long-term overdraft of water on the water level, correctly recognizing water level anomalies in the groundwater overdraft area and increasing the level of earthquake analysis and prediction.     

Chemical water types and their distribution in space and time in the Amsterdam dune-water catchment area with artificial recharge

The geology, hydrology and types of groundwater exploitation of the Amsterdam dune-water catchment area with artificial recharge of water from the river Rhine are briefly introduced. A classification of natural and artificial watertypes in the catchment is presented together with their genesis and distribution in space and time. The natural, vertical, hydrochemical zonation in fresh, brackish and salt groundwaters has been disturbed by decades of overdraft and the subsequent start of artificial recharge since 1957. Various mixed-water types resulted. A detailed case study of a part of the catchment area (around the Barnaart-Schuster Canal) covers a period of about 50 years. The decisive influence of geological inhomogeneities on the patterns of saltwater encroachment during the period of overdraft and on the patterns of infiltration of river water into the deep aquifer after the start of artificial recharge are demonstrated. The shifts in the subsurface positions of the various water types due to changes in the groundwater management of the catchment area are elucidated. They give an example of displacement and dispersion phenomena under field conditions.     

Decline of groundwater table in Beijing and recognition of seismic precursory information

This paper quantitatively analyzed groundwater table fluctuations caused by groundwater overdraft, and probed into the possibility of drawing earthquake precursory information from groundwater table variations on the background of groundwater overdraft. Main effect factors of groundwater regime in Beijing region include groundwater extraction and rainfall. The decline of groundwater table was directly related to regional groundwater overdraft. Using the method of correlation analysis, the paper analyzed the...     

Numerically modelling groundwater in an arid area with ANN‐generated dynamic boundary conditions

Groundwater is sensitive to the climate change and agricultural activities in arid and semi‐arid areas. Over the past several decades, human activities, such as groundwater extraction for irrigation, have resulted in aquifer overdraft and disrupted the natural equilibrium in these areas. Regional groundwater simulation is important to determine appropriate groundwater management policies, and numerical simulation has become the most popular method. However, most groundwater models were developed with static boundary conditions. In this research, the Minqin oasis, an arid region located in northwest China, was selected as the study area. An artificial neural network (ANN) was developed to simulate effects of weather conditions, agricultural activities and surface water on groundwater level in a dynamic boundary of the domain. Subsequently, a groundwater numerical model, named ANN‐FEFLOW model, was developed, with a dynamic boundary condition defined by the ANN model. The verifying results showed that the model has higher precision, with a root mean square error (RMSE) of 0·71 m, relative error (RE) of 17·96% and R² of 0·84 relative to the great groundwater change. Furthermore, the groundwater model has higher precision than the conventional groundwater model with static boundary condition, particularly in the area near the dynamic boundary. This study demonstrated that dynamic boundaries can improve the precision of the regional groundwater model in an arid area and that ANN can provide higher accuracy prediction capability for groundwater levels with dynamic boundary. Copyright © 2010 John Wiley & Sons, Ltd.     

地下水超采区水位长趋势动态分析

地下水多年过量开采水位持续下降, 不仅在观测资料中叠加了大量的疑似地震前兆, 严重地压低了来自孕震体的信息, 而且使正常的地震长、 中、 短周期变化背景扭曲, 前兆异常更加难辨。 本研究采用“线性拟合去趋势方法”对水位多年观测资料进行了分析。 分析结果表明, 线性拟合去趋势后水位10年左右的准周期结构清楚, 能有效地排除地下水超采的影响, 突出正常趋势变化背景, 放大潮汐信息量, 便于识别地震前兆。     

云南地区水位动态图像的前兆异常特征

利用云南地区多年的水位资料, 使用水位年变化率动态图像方法进行分析, 结果表明: ① 云南地区水位的年变化幅度似与未来地震强度有一定正比关系, 特别当某年水位最大变化率上升幅度大于0.35或下降幅度大于-0.35时, 次年往往会发生M_S≥6强震; ② 水位异常对应地震有区域性特征, 滇西北至滇东北地区以水位上升对应地震为主, 滇西南和滇西以水位下降对应地震为主; ③ 2000年以来云南绝大部分M_S≥5地震的发震地点都位于前一年水位上升(或下降)极值区或次极值区附近水位梯度较大的地带上。     

Identification of groundwater recharge sources and processes in a heterogeneous alluvial aquifer: results from multi‐level monitoring of hydrochemistry and environmental isotopes in a riverside agricultural area in Korea

We evaluated sources and pathways of groundwater recharge for a heterogeneous alluvial aquifer beneath an agricultural field, based on multi‐level monitoring of hydrochemistry and environmental isotopes of a riverside groundwater system at Buyeo, Korea. Two distinct groundwater zones were identified with depth: (1) a shallow oxic groundwater zone, characterized by elevated concentrations of NO₃^? and (2) a deeper (>10–14 m from the ground surface) sub‐oxic groundwater zone with high concentrations of dissolved Fe, silica, and HCO₃^?, but little nitrate. The change of redox zones occurred at a depth where the aquifer sediments change from an upper sandy stratum to a silty stratum with mud caps. The δ¹⁸O and δ²H values of groundwater were also different between the two zones. Hydrochemical and δ¹⁸O? δ²H data of oxic groundwater are similar to those of soil water. This illustrates that recharge of oxic groundwater mainly occurs through direct infiltration of rain and irrigation water in the sandy soil area where vegetable cropping with abundant fertilizer use is predominant. Oxic groundwater is therefore severely contaminated by agrochemical pollutants such as nitrate. In contrast, deeper sub‐oxic groundwater contains only small amounts of dissolved oxygen (DO) and NO₃^?. The ³H contents and elevated silica concentrations in sub‐oxic groundwater indicate a somewhat longer mean residence time of groundwater within this part of the aquifer. Sub‐oxic groundwater was also characterized by higher δ¹⁸O and δ²H values and lower d‐excess values, indicating significant evaporation during recharge. We suggest that recharge of sub‐oxic groundwater occurs in the areas of paddy rice fields where standing irrigation and rain water are affected by strong evaporation, and that reducing conditions develop during subsequent sub‐surface infiltration. This study illustrates the existence of two groundwater bodies with different recharge processes within an alluvial aquifer. Copyright © 2009 John Wiley & Sons, Ltd.     

巴丹吉林沙漠湖泊水分补给机制的模拟——以苏木吉林湖区为例

巴丹吉林沙漠气候干旱,蒸发强烈,与之形成鲜明对比的是沙漠腹地湖泊群的长久不衰,目前对于湖泊水分的补给来源仍存在争议.本文以水量均衡为基础,在苏木吉林湖区开展了降水、蒸发及湖水位和地下水位的动态监测,结合已有的水文地质资料建立地下水流动三维模型,重现湖区地下水位的季节动态变化,并基于模型进行水均衡分析.结果表明:苏木吉林湖区降水入渗补给量不足以平衡湖泊蒸发量,湖泊需要深层承压水的越流补给;湖水位和地下水位均呈现正弦曲线形态,11月最低,4月达到峰值,水位变幅分别为22和18 cm;湖区地下水多年平均总补给量为11620 m3/d,其中降水和承压水越流分别约占13%和87%,降水补给量夏季高、冬季低,承压水越流补给量季节变化不明显;承压水越流补给量可能主要来源于沙漠周边山区降水,未发现明显的水量亏空需要断裂导水来弥补.研究结果为巴丹吉林沙漠地下水资源分析及合理利用提供科学依据.     

大同-阳高地震水位异常的模糊识别与预报

采用模糊数学从属函数和异常系列方法，以大同－阳高地震为例，对强震发生的时间与地点预测进行研究。结果表明：模糊数学从属函数方法是提取水位异常的较好方法。强震发生前在一定区域内，水位群体异常在不同时间尺度上显示出增长和加速变化图象，这种图象可作为预报强震发生时间的标志。水位变化值异常的集中分布区与水位异常井位置在空间呈两组条带展布时，两组条带交汇地区可作为预报强震发生地点的标志