共查询到18条相似文献,搜索用时 671 毫秒
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2017年8月中旬至11月底琼海加积井水位水温同步大幅上升后至今呈转平形态的异常现象,通过开展井孔周边环境干扰的调查、井孔水体化学组分的分析、井孔构造的影响分析、周边观测井水位水温资料的对比分析以及区域构造活动的分析等工作,认为加积井水位水温的大幅上升后转平的现象非地球物理异常,推测原因应是观测段内深部含水层水补给量的增大上涌导致观测井水位水温同步上升,之后逐渐达到平衡,转而在高值的水平上呈平稳形态。而深部含水层水量补给增大的来源可能是观测井深110m以下至井底观测段内含水带揭露处井壁坍塌渗漏所致;也可能是其他的干扰所致,但具体的干扰源还有待继续核实。 相似文献
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为判别江苏睢宁苏02、03井静水位2014年7月下旬至2021年出现的同步转折上升异常变化是否为地震前兆异常,本研究通过开展降雨量影响分析、井孔含水层系统应力状态分析、井孔水及周边地表水化学组分的分析以及井孔周边地下水开采情况调查等工作,认为苏02、03井水位异常受应力变化影响的可能性较小,受环境因素干扰的可能性较大。为定性分析环境因素的影响,建立合理多元线性逐步回归模型,对2口井2008—2021年地下水位和降雨量、地下水开采量进行对比分析,全面考虑了影响地下水位动态变化的因素,得出最优回归方程。结果表明,前2年和前1年地下水开采量对地下水位有显著影响,而降雨量及当年地下水开采量对地下水位无显著影响,水位上升变化滞后于地下水开采量减少。 相似文献
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应力、应变或地震活动会打破地壳中流体原有的水-岩平衡状态,引起地下流体化学组分和同位素的变化。根据河北何家庄流体观测井氢氧同位素和离子化学组分测试结果,分析了该井的地球化学特征及与构造活动的关系。由氢氧同位素结果及高程效应,判定井水来源主要为大气降水,大气降水沿断裂裂隙渗入,深循环后温度增加,经溶滤作用等形成热水;按照舒卡列夫分类法,何家庄井水为Cl-Na.Ca型。受2015年9月14日昌黎M4.2地震的影响,区域应力变化使井孔断裂岩石裂隙增大,深部热水上涌,引起何家庄井水离子组分和氢氧同位素组成等发生变化。研究结果表明,对何家庄井流体地球化学特征进行分析,可以为井孔附近断裂构造活动和地震前兆异常分析提供地球化学依据。 相似文献
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针对2008年汶川MS 8.0地震后江苏地区的地震观测井水位上升现象,选取了苏18井和井周边地表水进行了水化学和物理分析,研究了井水位异常与地表水和大气降水的补给关系,讨论了井水补给来源及其与高邮-宝应MS 4.9地震的关系。离子含量和氢氧同位素结果表明,苏18井水主要为大气降水成因,存在一定的水岩作用。应用氯离子分析降水对地下水的补给,其结果显示大气降水在井水补给源中占了重要份额,井水位的突然上升与同期降水量增加有一定关系。水库水与苏18井水之间存在水力联系,大气降水增多致使水库水位升高,对该井水位变化有一定的影响。综合分析认为,大气降水的增多致使水库蓄水增加,水库水通过侧向渗透补给造成了2011年苏18井的水位显著升高。苏18井异常不是由构造活动引起的,作为高邮-宝应MS 4.9地震的前兆依据不充分。水化学和物理结合的方法为今后判别地下水位异常干扰提供了依据。 相似文献
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建水地下流体监测井水位骤降异常分析 总被引:2,自引:0,他引:2
2012年2月底至4月上旬,建水县地下流体监测站监测井水位出现了幅度近8m的显著下降变化.通过对该监测井与石屏—建水断裂带观测井同期水位进行对比分析,排除了监测井水位骤降异常是由构造活动引起的可能性.同时,调查了周边的抽水井,运用水文地质分析方法,结合当地水文地质情况,确定该监测井水位骤降异常是由附近的井孔抽水引起.充分了解当地的水文地质情况,根据地下水的运移规律,结合实地调查,可以对地下水异常给出相对合理的解释,并进一步判断地下水异常是否是构造活动引起的地震异常. 相似文献
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鲁豫交界地区深井水位持续大幅度下降原因分析 总被引:4,自引:2,他引:2
鲁豫交界地区豫01、11井和鲁27井等3口地震观测深井的水位于2006年后出现了准同步的异常下降变化,下降幅度3 ~12m不等.经调查落实,发现该地区近年来地热开采活动日益增强,开采量逐年增大,并且开采层与异常井水位观测层同属于奥陶系热储层.为此,本文依据聊城-兰考断裂带附近区域的水文地质构造特征,建立了三维地下水流动模型,基于周边地热开采量数据和相关含水层参数,运用有限差分方法计算了地热开采所引起的区域水位降落漏斗,并分析了水位下降异常的时间演化和空间分布特征.结果显示,聊城-兰考断裂带附近区域自1995年开始地热开采活动以来,其逐年增加的地热开采量与地震观测井水位的下降幅度之间存在较好的对应关系,分析认为鲁豫交界地区3口深井水位的准同步异常下降与周边地热开采活动有关. 相似文献
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A detailed investigation was carried out to evaluate long-term groundwater level fluctuation in regular monitoring wells constructed by the Ministry of Water Resources in Barka, Sultanate of Oman. For this study, groundwater level data for 71 wells and rainfall data from six stations were collected from 1984 to 2003 and analysed. Based on long-term water level fluctuation, groundwater wells are classified into three groups. In group 1, water level shows a long-term cyclic trend without yearly fluctuation whereas in group 2 the water level declined continuously until 1995 followed by a constant water level. In group 3, water level decreases continuously throughout the study periods with rapid annual cyclic variation. Group 1 wells show high water-level fluctuations (5 to 10 m) and seem to be regulated by discharge (lateral flow) from this aquifer and recharge from the adjacent Jabal Akhdar mountainous region. Constant trend in water level after 1995 in group 2 wells illustrates the advancement of saline–fresh water interface to the inland due to heavy pumping which is justified by higher electrical conductivity and Cl/HCO3 ratio. In group 3 wells, the water level dropped continuously due to overabstraction by agricultural farms and human settlements. In addition, wells existing near the recharge dams express the influences of recharge dams and rainfall, and exhibit high water-level fluctuations during heavy rainfall periods. The long-term regional variation indicates that water level drops continuously in the coastal and central parts of the study region. Linear regression analysis revealed that the decline in water level is 0·3–0·4 m year−1 near the coastal and central parts of the study area and is almost constant in the remaining area. We conclude that the contribution of man-made activities on groundwater level is well compared with natural factors. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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穿越断裂带的观测井能够提供特殊的构造运动信息,其水位动态是构造活动、降雨等各种因素综合作用的结果.对由降雨引起的水位动态进行模型解译,有利于更加准确地提取断裂带的构造活动异常.根据断裂带地下水循环的基本特征进行简化,利用响应函数法描述入渗补给的滞后特征,建立了降雨-水位动态的组合水箱模型.该模型被用于分析北京八宝山断裂带大灰厂观测孔2008年上半年的水位动态,发现2008年5月存在显著的异常.这种异常可能与局部或区域的构造活动有关,也可能是断裂带结构参数变化的结果. 相似文献
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地下水动态的异常变化既有可能是地震前兆异常信息, 也有可能是某种环境干扰所引起, 如降雨和地下水开采等. 如何及时识别并排除环境干扰, 对于成功判定地震前兆异常至关重要. 云南姚安井水位于2009年10月后出现了下降趋势的异常变化, 截止2011年底, 最大下降幅度达3 m. 为分析该井水位异常变化的形成原因, 依据姚安井水文地质环境特征, 建立了相关的数学物理模型, 定量分析了降水量和地下水开采量对该井水位的影响. 分析结果表明, 姚安井2009年后出现的水位大幅下降可能与区域降水量减小导致的地下水开采活动增强有一定的相关性. 文中所采取的异常识别与分析方法, 对今后地下水动态异常识别及前兆信息判定工作具有一定的借鉴意义. 相似文献
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Hydrogeological Studies to Identify the Trend of Concealed Section of the North Tabriz Fault (Iran) 下载免费PDF全文
The North Tabriz Fault (NTF) is the predominant regional‐scale tectonic structure in the northwest of Iran. In the east side of the city of Tabriz, a portion of the fault trend has been completely concealed by recent sediments and urbanization. In this paper, some hydrogeological methods are used to locate the concealed sector. As is clear from the pumping tests results, despite the fact that the northern observation wells were closer to the pumping wells than the southern ones, they have not been affected by pumping. Conversely, all southern wells were affected by pumping and displayed decline of the water table. In addition, obvious differences in groundwater levels combined with clear differences in groundwater quality within a short distance across the probable fault trend are sufficient reasons for the presence of the fault that behaves as a barrier to groundwater lateral flows. Significant change in the elevation of the bedrock base of the aquifer over less than 200 m suggests that the fault has near vertical dip. These results indicate that the inferred trend of the NTF closely conforms to its actual trend. Therefore, the hydrogeological studies can be complementary tools to determine the position and trend of concealed faults. 相似文献
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Based on the well water level data in Majiagou Mine in Tangshan City since 2000, it is suggested that the water level rise from 2008-2014 is possibly associated with reduced infiltration caused by less precipitation, together with the effect of less groundwater exploitation. However, the water level rise from 1992-1998 cannot be interpreted properly if we extend the data source back to 1991. After comparing the data with long-term water level data of five wells with different hydro-geological units in Tangshan and Qinhuangdao, the study indicates that the long-term water level variation cannot be only attributed to the effect of less precipitation and the control of groundwater exploitation, but also with the influence of regional stress field change. With the support of regional geological and tectonic information, combined with the comprehensive analysis of CBM data obtained from the coal field, new understandings of the dynamic characteristics of annual variation are obtained. 相似文献
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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 相似文献