易门井数字化水位水温同震响应及其机理探讨

研究了易门地震前兆观测井数字化水位水温观测资料对2004年12月26日印尼8.7级、2008年5月12日汶川8.0级和2011年3月11日日本9.0级大震同震响应特征,探讨其同震响应机理,给出水位水温同震响应的合理解释。表明易门井水位水温同震变化总是水位震荡下降—迅速恢复、水温迅速下降—缓慢恢复,形态相似。与观测井所在的地质构造、井深以及探头深度密切相关。     

降雨量对深井静水位的影响机制分析——以鹤壁井观测数据为例

我国地震地下水动态观测井水位动态直接受降雨干扰,影响地震前兆信息识别。文章以鹤壁观测井为例,基于2014-2019年鹤壁井静水位观测数据及当地降雨量资料,对鹤壁井静水位主要影响因素及机制进行研究,结果可知:鹤壁观测井的水位相对较浅,静水位受降雨因素影响尤为明显,静水位与降雨量有很强的相关性,变化特性与Gauss-Seidel迭代法一致。在降雨因素对于静水位的影响大于其他因素影响时,影响系数in作为未知项,根据in和以前的降雨量数据,我们可逆推未来一段时间的水位数据,对评估水位观测井的观测效能及数据异常核实等工作具有指导意义。     

远场大震同震水位振荡、水温下降类型机理初步研究

在2004年12月26日印尼苏门答腊M_s8．7级地震同震水位、水温变化类型的对比分类中,发现出相当具有规律性的一类变化类型：在某些观测井当水位出现振荡(水震波)的时候,同井水温绝大多数会有个几十分钟到数小时的从下降到恢复的过程。为此笔者又收集了其中的典型变化观测井,北京良乡井和河北唐山矿井2001年数字化以来30多次不同远场大震水位、水温的同震响应资料,发现无一例外都具有相同的规律性。在此基础上,笔者提出了对于同震水位振荡,温度下降的气体脱逸模式,并对气体脱逸的两种途径进行了动力学的分析。     

“动水位”观测较静水位观测更敏感

万迪堃等在《华北地震科学》第8卷第2期撰文认为,我国地震地下水动态观测井网建点以来所取得的资料表明,同样是承压水,静水位和“动水位”的映震能力有明显不同,“动水他”的映震能力明显优于静水位。“动水位”观测是将自流井的流量观测转变为“水位”观测的方法。“动水位”是指在一定放水量条件下,井管中的水面相对于排水管中心的高度,与水文地质学中动水位的概念是不一致的,不是真正的动水位,它的变化反映排水量的变化。“动水位”观测较静水位观测更“灵敏”的原因初步认为有四个方面:首先“动水位”观测实质上     

福州市地下水开采对华林1号井水位观测井的干扰

随着海峡西岸经济建设的飞速发展,福州市温泉的开采量日益增大,这对于布设在温泉区域内的地震水位观测井造成了严重地干扰,导致水位正常的固体潮特征受到破坏,水位的日变化幅度大（1～2m左右）,年变化幅度达到13m左右,作为地震地下流体微动态观测,该井的水位观测资料已经无法用于地震分析预报,而城市的发展地下水的开采已是不可逆转;因此,针对城市防震减灾与经济建设发展之间的矛盾提出几点思考。     

湖南湘阴井水位的一次大幅下降异常成因分析

通过检查湘阴井的观测系统、排查其观测环境,包括对温度、气压、降雨量、湘江水位以及周边施工作业等的排查,并对湘阴井和湘江水的水样进行水质成分和氢氧同位素分析,认为湘阴井水位自2019年7月中旬开始出现的大幅下降异常现象是在当时湘阴县降雨量明显减少且湘江水位降低的情况下,附近工地施工引起的水位下降,不是地震前兆异常.     

傍河地下水位监测断面的优化设计

为了对傍河地下水位监测断面进行优化设计,更好地掌握地下水位动态时空变化特征,以安徽省亳州市河水-地下水监测断面为例,分别采用克里金法和时间序列法,通过分析监测断面上9口地下水位观测井及河水位观测点在1982年1月—1998年12月的水位观测数据,对观测井空间布局、井数和观测频率进行优化。结果表明：空间布局优化后的观测井数量由原来的9减少到3,平均相邻井距为1 000 m,优化后的水位克里金估计标准误差平均值为0.019 2 m,误差波动范围较小;观测频率优化后由5日一测变为10日一测,能够满足观测精度要求。     

直接利用动水位资料进行预测预报的初步探讨

当前,许多开采地下水的灌区,一般都没有设立专用的观测井,多利用生产井来进行水位观测。这样,在每年长达七个多月的开采期间,就只能测得动水位而测不到真实的静水位,而水位的预测工作却是建立在静     

JWS—139型手提式井温水位仪

为了提高在长期水文观测孔中所测资料的质量,并减少工作量,我们设计制作了手提式井温水位仪,一次可取得孔内水位及逐点井温资料。      

永安井水位大幅度异常成因的调查分析

2001年7月18日起,永安井水位出现了持续的大幅度上升的变化过程。经调查落实,这是由于该井附近的另一口并多年来的开采后,于2001年7月18日突然停止抽水,而使地下水的补给量增大,造成地下水大幅度上升。这对研究临近并抽水对地震地下水动态观测井的水位动态影响提供了实例,对区分深井地下水前兆异常与抽水干扰有一定的参考价值。     

Reservoir Triggered Seismicity (RTS) and well water level response in the Koyna–Warna region, India

Water level fluctuations in twenty-one observation wells have been monitored for the last 10 years around the seismically active Koyna–Warna region, western India where earthquakes continue to occur even after four decades of the initiation of the seismic activity in the region. Fourteen of the observation wells act as volume strain meters as their water levels show earth tidal signals. Our analysis suggests three types of response of the well water levels to seismo-tectonic effects, i) one to local earthquakes, ii) to regional and teleseismic events, and iii) to local fluctuations in rock strain on regional scale. We observed five cases of co-seismic step-like well water level changes, of the order of few centimeters in amplitude, related to earthquakes in the magnitude range 4.3 ≤ M ≤ 5.2. All these earthquakes occurred within the network of wells drilled for the study and within 25 km distance of the recording wells. In three cases, drop in well levels preceded co-seismic step-like increases, which may be of premonitory nature. The second type of response is observed to be due to the passing of seismic waves from regional and teleseismic earthquakes like the M 7.7 Bhuj event on January 26, 2001 and the M 9.3 December 26, 2004 Sumatra earthquake. The third type is a well level anomaly of centimeter amplitude coherently occurring in several wells. The anomalies are similar in shape and last for several hours to days.From our studies we conclude that the wells in the network appear to respond to regional strain variations and transient changes due to distant earthquakes. The two factors which are important to co-seismic steps due to local earthquakes are the magnitude and epicentral distance. From the limited number of events we found that all local earthquakes exceeding M ≥ 4.3 have produced co-seismic changes. No such changes were observed for earthquakes below this magnitude threshold.     

屋顶雨水回灌裂隙岩溶含水层连通示踪试验

雨水回灌后对岩溶水的影响分析和效果需要对回灌井和下游的观测井监测数据说明。由于岩溶含水层中岩溶发育极不均匀,在测定地下水位并判定出地下水流向的基础上,连通示踪试验是选择与回灌井相对应的观测井的有效办法。用氯化钠作为示踪剂,监测不同测井不同埋深地下水电导率随时间变化的方法确定了岩溶水观测井选址、岩溶含水层的结构及水文地质条件。示踪试验结果表明,3#观测井(西院井)可用来监测雨水回灌效果,并计算出该地区的地下水势流速在9 m/h～20 m/h之间。该成果对北方地区岩溶含水层回灌和环境评价具有重要的参考价值。     

奇村地震水汞动态图象分析

本文通过对山西省奇村地热异常地区地震水汞动态图象的特征分析，认为该水汞测量值受干扰小，其水汞值变化可反映地下深部信息。监测井中水汞值变化受区域地震活动地应力和应变状况及地质构造条件影响。监测井的汞动态可反应地区水汞值变化趋势。     

Water level fluctuations due to earthquakes in Koyna-Warna region,India

Earthquakes cause a variety of hydrological phenomena, including changes in the ground water levels in bore wells. The Koyna region in the peninsular shield of India, hitherto considered stable in terms of seismic activity, has been active since 1967. More recently, the earthquakes have been localized to the newly impounded Warna reservoir, which is located south of Koyna, where a burst of seismicity occurred in 1993. The region continues to remain seismically active even after four decades. Twenty-one bore wells were drilled around the seismic source volume in the region to observe water level changes resulting from earthquake phenomena. Our studies have shown coseismic anomalous water level changes to be associated with the moderate earthquakes of April 25, 1997 and February 11, 1998. Our results show that changes in the ground water level in bore wells are correlated with micro-earthquake activity, both preceding and following moderately sized earthquakes. The results have implications in enhancing our understanding of earthquake mechanisms.     

气压对观测井水位的影响及校正方法

地下水监测能为有效管理地下水资源提供重要信息。大气压力对观测井水位有着重要影响,正确地分析这种影响可以有效判别地下水的流向,判断含水层的性质、识别井筒存储效应（well bore storage effects）和井薄壁效应(well skin effects), 计算包气带中空气的扩散度等。随着现代化监测仪器的推广使用,高质量的监测数据为分析气压对观测井水位的影响提供了基础和保障。系统分析了不同类型含水层中井水位对大气压力的响应模式,并对校正气压对水位影响的方法进行了分析和讨论。最后,以北京平原区两口监测井为例,运用多元回归反卷积方法分析了气压对井水位的影响,并对井水位进行校正。结果表明该方法能有效地分析和校正观测井水位中的气压影响。     

抽水井周围饱水介质场三维水位动态观测及地下水流运动特征

利用设计建造的抽水试验装置,采取多项潜水及承压水的抽水试验,获得大量的抽水井周围饱水介质场三维动态观测数据。试验发现：无论是潜水还是承压水状态,抽水井附近观测井的水位变化,均具有距抽水井愈远愈高、愈近愈低的漏斗状分布,抽水井附件的地下水位降落漏斗是显著的;同时发现每个观测井不同高度上的观测点的水位,均呈现上高下低的特征,说明地下水具有由上到下的运动分量,地下水由周边的供水边界向抽水井聚集运移时,运动方向是下斜向的,潜水如此,承压水也如此。分析认为,这是水头压力与水体自身重力同时起作用的结果。由此推断,在抽水时,靠近承压水含水层顶板存在强势水流,且越靠近补给源,这种强势水流越强。     

断裂两盘井水位同震响应特征对比分析——以北京八宝山断裂带中段大灰厂两观测井为例

地震常引起分布于断层两盘观测井的水位同震响应动态变化特征不同。而研究断裂两盘观测井同震响应能力、水位变化特征的差异性及其控制因素,有助于揭示断裂带的渗透性演化过程、可深化地下水位对地震响应机理的认识,对于指导地震观测井网布局具有重要意义。本文尝试从北京八宝山断裂带中段（大灰厂）上下两盘井的水位同震响应次数、形态、幅度、记震能力等方面进行对比分析,通过去除趋势项,采用数字滤波求取井孔气压系数,采用Baytap-G程序求取潮汐参数,并反演出7次大地震对大灰厂区两口井所在含水层产生的体应变量,进而判别两盘震前震后渗透性的变化。结果显示,两口井同震响应特征具有明显差异,上盘井对大震的同震响应次数较多、能力较强;这不仅与断裂带起屏蔽作用有关,而且与井所处含水层渗透性呈不同规律变化密切相关。     

北京平原地下水水位监测网优化

文章在北京市地下水水位监测现状基础上,分潜水和承压水对北京平原地下水监测网的监测密度和监测频率进行了优化设计。主要采用编制地下水动态类型图的方法进行了地下水水位监测网的优化,克里金插值法能定量评价依据监测网观测值绘制的地下水水位等高线的精度,因而可以用来评价监测优化结果。并根据时间序列分析和统计检验提供的定量标准优化了地下水水位监测频率。优化后,北京平原共有监测孔400眼,其中利用原有监测孔300眼,新设计监测孔100眼,手工监测频率由原来的每月6次优化为每月1次,专项高频率监测可以由地下水自动监测仪实现。文中还对地下水自动监测仪(DIVER)的监测结果和手工监测结果进行了对比评价,提出了地下水水位监测网的维护、管理措施和信息发布方式。     

Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea

Hydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with M_L 5.8 and M_L 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The M_L 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

     

乾安县地下水位动态变化特征及成因分析

依据乾安县2006至2016年地下水位动态监测资料,分别选择潜水观测井和承压水观测井进行研究,总结出研究区潜水地下水位动态变化特征为降雨渗入-径流-蒸发型,承压水地下水位动态变化特征为越流-径流型、径流-开采型和开采型。潜水地下水位动态变化受气象等自然因素影响明显,承压水地下水位动态变化受开采人为因素影响明显。近十年来,研究区地下水位呈现整体下降,特别是在集中开采区,地下水位降幅最大。研究结果可为地下水资源合理开发利用提供科学依据。