电阻率法山区找水技术应用探究

电阻率勘测法一般是由正负两个电极向地下送入电流,地下的电流场受不同电阻率岩层的影响而不同分布规律。因此在地表观测电位,就能推知地下电阻率的分布情况,进而推断分析地质情况达到找水的目的。尤其对山区的岩石裂隙水和层间裂隙水的探测非常重要,这种找水方法对山区干旱地区寻找地下水起到关键的作用。文章就电阻率勘测法再山区找水技术应用进行了探讨,旨在为类似地质情况的地区找水技术提供借鉴和参考。     

基岩山区用激发极化法找水效果好

黑龙江省密山县水利打井队在基岩山区应用激发极化法找水定井位,效果十分显著。近年来共定井位73眼,成井72眼,成井准确率达到93.7％,为解决山区病区人畜饮水和抗旱水源起到了重要作用。应用激发极化法找水是最近几年才发展起来的新技术。它对含水层反映比较直观,有些用视电阻率法反映不明显或容易漏掉的薄含水层,用这种方法都可以找到。在贫水的基岩山区、半山区寻找断层裂隙水,或在古风化壳破碎带寻找裂隙孔隙水,用激化极化法比其他方法优越。这种方法能同时测出视电阻率、激发比、极化率、衰减度四     

大兴区奥陶系岩溶裂隙水保护对策

北京市大兴区供水主要以地下水为主,而其中奥陶系岩溶裂隙水占较大比重。通过对奥陶系岩溶裂隙水的补给、径流和排泄以及水化学特征等水文地质条件的综合分析,得出该含水层的主要补给来源为第四系水的垂向越流入渗,进而建立第四系、岩溶裂隙含水层联合的地下水数值模型,划定水源地保护区,并分别制定水源地区和非水源地区的保护措施,为大兴区奥陶系岩溶裂隙水的保护提供科学依据。     

激发极化法在牧区找水的初步认识

一、激发极化法找水的基本原理电阻率法找水是通过电极往大地供电,根据不同岩层电阻率的差异,判别含水层,达到寻找地下水的目的. 激发极化法是利用二次场电位差衰减特性,判别含水层,从而找到地下水源. 用供电电极向地下供电期间和断电以后,测量电极上观测到的电位差随时间变化的曲线如(图A)     

李雅庄矿区地下水水化学及环境同位素特征研究

根据李雅庄煤矿水文地质勘查成果,对矿区主要含水层地下水水化学特征进行分析,并利用环境同位素方法进行水体来源研究。结果表明李雅庄矿区各含水层地下水水质存在一定差异;石炭系太原组岩溶裂隙水水质类型单一,与二叠系裂隙水相比,阴离子SO42-含量明显偏低,阳离子Na+含量则明显偏高;奥陶系峰峰组岩溶水水质相对复杂,并呈现出明显的水平分带性;奥陶系上马家沟组岩溶水与峰峰组岩溶水相比,水质类型及阴、阳离子含量均有明显差异。环境同位素研究结果表明,水样δD、δ18 O值偏离当地雨水线较远,说明太原组岩溶裂隙水及奥陶系岩溶水接受大气降水补给条件相对较差;水样氚浓度分析结果说明太原组岩溶裂隙水及奥陶系岩溶水未接受近年大气降水的补给,属于古水和新近入渗水以及二者混合水。     

高密度电阻率法在水文地质勘查中的应用

介绍了近年来在水文、工程、环境物探领域中兴起的高密度电阻率勘测方法的基本原理,并针对内蒙古扎鲁特旗南部地区开展高密度电阻率法测试的研究与应用。通过高密度电阻率法测量获得实测数据,进行反演分析,求得差异反演区内地层的空间分布,同时结合钻孔实验资料及同期核磁共振数据,得到最终GMS数值模拟的较准确的含水层空间分布模型,确定出该区域含水层厚度的空间结构特征,对区域地下水系统的识别分析提供了可靠依据。     

物探技术在找水领域中应用的探讨

主要对物探技术在水找领域中的应用进行论述。根据在广西应用电法找水成功的实例,说明不管是在崇山峻岭的岩溶地区,还是在平原、低山丘陵的砂页岩地区,应用小“极距”(AB/2)电法找水都大有可为;探索出视电阻率与地下水贫富程度的规律;说明“联合剖面”法联剖曲线奇特异常在找水中应用的方法。     

西南典型岩溶区地下水防污性评价方法

与第四系含水层相比,西南岩溶区常缺少天然的防渗或过滤层,岩溶含水层的地下水防污能力较差,地表水和污染物很容易通过落水洞等岩溶形态直接进入含水层或地下河。现以典型岩溶区———桂林市区为例,在将该地区依据地貌分为7个亚区的基础上,结合岩溶水二元补给特性,尝试运用"二元法"对桂林市岩溶区地下水的防污能力进行分区评价,评价结果显示,桂林市区除洪积扇亚区一带地下水的防污能力强以外,其他地区的岩溶地下水都面临着防污能力差的问题,尤其是在落水洞发育的峰丛洼地、峰丛谷地两个亚区,如果不加以保护,地下水极易被污染。通过与前人成果的对比,该方法将径流特征作为一个主要的评价因子,所得结果更为合理,而且本方法具有所需数据量少,可以进行定性评价等优点,可在我国西南岩溶区中加以推广。     

乌江银盘水电站右岸河湾地块岩溶渗漏分析

乌江银盘水电站近坝地段右岸为一河湾地块,主要分布三迭系至寒武系地层,其中岩溶含水层在水库内外均有出露,且在河湾地块中连续分布,水库蓄水后,库水有可能通过河湾地块岩溶含水层向乌江下游产生渗漏.通过对河湾地块岩溶水文地质的调查资料,根据岩溶含水层与隔水层的分布特征,地下水的补给径流条件,地下水的出露高程,分析成库后库水沿河湾地块岩溶含水层向水库下游渗漏的可能性以及对工程的影响.     

阜平县太古界变质岩区地下水的赋存规律与电性特征

阜平县太古界变质岩经历了多期变质深熔作用,以揉塑性片麻岩为主,地层致密柔韧,富水性差,找水难度较大。在地质调查、物探勘探及钻探验证相结合的基础上,较系统地分析了变质岩区构造裂隙水、风化壳裂隙-孔隙水、层状裂隙水和接触型基岩裂隙水四种地下水类型的赋存规律及电性特征。结果表明:构造裂隙水主要赋存在构造破碎带内;风化壳裂隙-孔隙水分布普遍,水量小,一般沟谷风化壳与断裂叠加带富水性较大;层状裂隙水和接触型基岩裂隙水主要赋存在硬脆-软塑岩性组合的接触带(面)上。在视电阻率等值线断面上,构造裂隙水呈现为陡降低阻带曲线;与构造复合的风化壳裂隙-孔隙水,呈现为凹型低阻曲线;层状裂隙水面状分布,呈现为水平低阻曲线;岩脉接触型基岩裂隙水,呈现为条带状高阻+类断层低阻反映。     

Assessment and Management of a Desert Basin in Kuwait

ABSTRACT

The study area, Umm Gudair, is located in the southwest corner of Kuwait. It occupies an area of ≈ 4.84 × 10⁹ ft². The brackish ground water is derived from the two main aquifers within the Cenozoic sequence. These are: the Kuwait Group aquifer (Miopleistocene) and the Dammam aquifer (Eocene). In the study area, the two aquifers are treated as a single reservoir Forty-one production wells, locally called “dual completion wells” were finished in the aquifers. This research identifies the hydrogeologic properties and the water quality of the aquifers. In addition, the article discusses the application of the surface electrical method Schlumberger configuration to correlate and delineate the areal distribution of the apparent resistivity with the aquifer salinity, and the occurrence of a water-bearing formation. The results will be use for assessment and management of the groundwater reservoir The water quality of the two aquifers is relatively poor The T.D.S. ranges between 3,130-4,740 mg/L. The hydrochemical facies are calcium-sodium cation facies and chloride-sulphate anion facies. The ground water is classified as a NaCl water type, however two genetic water types are identified: the MgCl₂ and CaCl₂ are of marine origin and are old marine formations. The aquifer is semiconfined to confined The average transmissivity, which increases toward the N and N-E, is 20,965 Igpd/ft. The geophysical studies conducted along seven profiles with 19 vertical electrical soundings reveal three distinct layers. The first layer is composed of dry gravel and has a resistivity of 80–220 m. For the second layer, the resistivity ranges between 5–9 Ωm. It is assumed to be a clayey layer saturated with brackish water; whereas the third layer corresponding to a limestone formation, has a resistivity of 25–700Ωm. The apparent resistivity decreases in the direction of the increasing salinity From the flow-net analysis, the amount of ground water entering the aquifer along the border with the Saudi Arabia is 2.3 × 10⁶ Igpd, while the average daily production from the Umm Gudair field is 13.5 × 10⁶ Igpd, It is obvious that the daily abstraction rate is higher than the daily flow toward the aquifer Therefore, in the future, if the daily abstractions continue to exceed the daily water flow through the aquifer a serious decline in the water level will result.     

苏丹中部半干旱地区含水层特征的评价

苏丹中部的北杰济拉(Gezira)省的含水层为杰济拉含水层和白垩系含水层.在确定含水层水文地质参数的基础上,绘制了地下水水位等值线图,并通过矿化度的空间分布对地下水的化学特性进行评价.对水文地质参数的计算采用了雅各布方法和泰斯恢复水位法,通过对地下水中主要化学成分的分析来评价地下水水质,并绘制有关的水化学特性图.测得杰济拉含水层的平均导水系数和渗透系数分别为368 7m2/d和34 03m/d,均小于白垩系含水层的407 2m2/d和43 17m/d.杰济拉含水层物理化学成分的浓度明显高于白垩系含水层.白垩系含水层水质较好,适宜用作生活用水及饮用水.     

Groundwater Response to Tidal Fluctuation in an Inhomogeneous Coastal Aquifer-Aquitard System

This paper investigates tide-induced groundwater fluctuation and submarine groundwater discharge (SGD) in a leaky inhomogeneous coastal aquifer system with an upper unconfined aquifer, a lower confined aquifer, and an aquitard between them. The upper left aquifer is formed due to land reclamation. The SGD defined as the groundwater flow from land into the sea is controlled mainly by the hydraulic gradient between land and sea. An analytical expression is developed to discuss and assess the effect of inhomogeneity on the groundwater head fluctuation in the leaky aquifer system. Joint effects of aquifers’ parameters such as leakage and hydraulic diffusivity on the groundwater head fluctuation and SGD are investigated. The predicted results from the analytical expression indicate that the groundwater head fluctuation in both unconfined and confined aquifers is dependent on dimensionless leakages and increases with dimensionless hydraulic diffusivity.     

滨海地区潮汐对地下水位变化影响的统计学分析

本文采用互相关分析、谱分析、Mallat分解重构算法等理论与方法,利用实测的潮汐资料和观测井水位资料,并结合实测的电导数据,从统计学上分析计算了广东省珠海市唐家镇附近,滨海含水层地下水水位波动的原因以及波动的位相、周期、振幅对海潮潮汐的响应。结果表明,微承压水和基岩裂隙水水位波动的原因均是含水层承受的质量负荷随潮汐的变化而变化;微承压水水位波动相对海潮潮汐的位相延迟时间约为7.0h,基岩裂隙水约为1.5h;微承压水水位波动的周期组成成份比海潮潮汐略少,基岩裂隙水水位波动的周期组成成份与海潮潮汐基本相同;微承压水水位波动的振幅约为海潮潮汐的1/100左右,基岩裂隙水为1/3左右;本研究区域海潮潮汐对浅层基岩裂隙水水位波动的水平影响范围在1 000m之内。     

Particle Filters to Estimate Properties of Confined Aquifers

Involving a limited resource, the assessment of groundwater aquifers is of utmost importance. A key component of any such assessment is the determination of key properties that permit water resource managers to estimate aquifer drawdown and safe yield. This paper presents a particle filtering approach to estimate aquifer properties from transient data sets, leveraging recently published analytically-derived models for confined aquifers and using sample-based approximations of underlying probability distributions. The approach is examined experimentally through validation against three common aquifer testing problems: determination of (i) transmissivity and storage coefficient from non-leaky confined aquifer performance tests, (ii) transmissivity, storage coefficient, and vertical hydraulic conductivity from leaky confined aquifer performance tests, and (iii) transmissivity and storage coefficient from non-leaky confined aquifer performance tests with noisy data and boundary effects. On the first two well-addressed problems, the results using the particle filter approach compare favorably to those obtained by other published methods. The results to the third problem, which the particle filter approach can tackle more naturally than the previously-published methods, underscore the flexibility of particle filtering and, in turn, the promise such methods offer for a myriad of other geoscience problems.     

太行山前丘陵区基岩裂隙水赋存的非均一性和易疏干性特性

根据碧流河流域生态特征,分析了适合该流域的河道生态需水计算方法,应用于碧流河水库兴利调度,并以生态目标为基础,确定下游河道的生态需水量。结果表明:碧流河水库下游河道生态环境基本供水量及改善供水量分别需要2 765万m3和4 250万m3。为了保护和改善河流生态环境,促进流域水资源可持续利用,需要采取最严格的用水管理制度,加大非常规水源的开发利用力度,并结合调水工程以及河库连通工程等相关措施。     

A Framework for Ground Water Management Based on Bayesian Network and MCDM Techniques

Groundwater resources are steadily subjected to increasing water demands. The aquifers are considered as the most accessible source of fresh water. In recent years, they have been faced with severe water withdrawal in arid and semi-arid countries like Iran and thus some aquifers was considered as forbidden aquifers that it means the water withdrawal from these aquifers is unauthorized. Given a critical situation, groundwater resources management in the form of tools such as monitoring the level of the aquifers and developing the restoring scenarios is essential. Therefore, for this purpose, a framework has been developed based on prediction of groundwater level using Bayesian Networks (BNs) model. Furthermore, Multi Criteria Decision Making methods (MCDM) techniques proposed and employed for ranking of proposed groundwater management scenarios. This framework was evaluated for restoring the Birjand aquifer in Iran in different hydrological conditions. A probabilistic Dynamic BN was proposed for groundwater level prediction under uncertainties. After analyzing the obtained results, the applicable short term scenarios for groundwater management as well as appropriate economic, social and technical criteria were defined for decision making procedure. Then, using elicitation of decision makers’ opinions on the relative importance and performance of criteria, SAW, TOPSIS and PROMETHEE-II techniques were applied to rank the scenarios and the obtained results were aggregated by Borda method for final ranking of the scenarios. Lastly, the final results demonstrates the capability of the proposed framework for groundwater resources planning and management which can be employed for reducing the risk of aquifer level declining.     

滨海深部含水层地下水排泄量评估

为了进一步计算评估滨海深部含水层地下水排泄量,以一个海底深部承压含水层系统为例,包括承压含水层及上覆弱透水含水层(海底),在内陆补给上考虑了与时间无关的年平均补给(常数)和由季节性降雨引起的周期性补给两种情况,从而建立了一个描述承压含水层中海底地下水排泄的数学模型,并得到其解析解。继而利用解析解分析了位于美国南大西洋Onslow海湾的SGD。结果显示,SGD排泄宽度变化范围为0.5~3.0 km,在承压含水层中海岸线处高于平均海平面1.0 m的水头值,其所产生的SGD速率为1.1~10.0 m2/d。     

江汉平原地下水位动态变化特征分析

通过辨识江汉平原含水系统的水文地质结构,深入分析了地下水位动态变化特征及其影响因素,进而揭示了研究区地下水时空演变规律。结合地下水流系统分区分析了研究区的降雨-径流关系和地下水动态类型。同时,运用数理统计方法分析了累计水位升幅和累计降雨量之间的关系。结果表明:研究区内地表水除丰水期补给地下水外,其余时段地下水补给地表水;研究区不同含水层地下水位关系总体为深层孔隙承压水位中层孔隙承压水位浅层孔隙潜水位;研究区地下水对降雨入渗产生的滞后效应表现为低水位期滞后5~7 d,高水位期滞后1~2 d。研究结果对该地区地下水资源的评价管理具有现实意义。