江苏沿海地区深层地下水开发利用现状及环境地质问题

江苏沿海地区深层地下水在开发利用过程中，由于开采布局不合理和存在“三集中”(开采层次集中、开采地段集中、开采时间集中)以及水文环境地质条件脆弱等因素，出现水位逐年下降，并形成区域性降落漏斗，致使部分地段地下水资源枯竭、水质成化和诱发地面沉降等诸多环境地质问题。本文着重分析沿海地区深层地下水开发利用的6个阶段(初级、城市开采、城市超采、区域超采、区域控制开采和区域压缩开采阶段)、区域降落漏斗的3个发展过程(1986年、1995年和2002年)和因深层水超量开采诱发的水资源枯竭、水质成化和地面沉降等环境地质问题的发育特征及演化趋势，从地下水资源管理和可持续发展的角度，提出深层水的保护规划、浅层咸水、海水资源的开发利用、实行强制节水、污水资源化和发展海洋性产业的对策建议。     

大陆岛地下水动力学特征—以湛江东海岛为例

东海岛是一具有独特水文地质条件的大陆岛,浅层含水层与大陆以浅海湾相隔,中深层承压水含水层与大陆地下水系统紧密相连。为了深入地认识大陆岛地下水水动力学特征,以湛江东海岛为例,阐述了其水文地质条件,并分析了东海岛浅、中、深层地下水的流场和动态特征。分析结果表明,东海岛为一个典型且独特的大陆岛,岛内和大陆的部分浅层含水层由湛江湾相隔,岛内中、深层含水层和大陆中、深层含水层通过湛江湾相连,且具有统一的水位分布,并保持着密切的水力联系,岛内中、深层地下水由南向北径流补给湛江市区的降落漏斗中心;滨海及海水区域浅层含水层及其下伏的粘土层构成了防止海水入侵中、深层地下水的保护层;浅层地下水流场基本保持天然状态,水位动态特征主要为入渗径流型,水位变化与降雨量相关;中、深层地下水流场以人工流场为主,地下水由南向北径流,水位动态类型主要为开采动态型,水位变化主要受到开采量变化的影响;在近海岸地区,地下水动态表现为潮汐效应型,在潮汐作用下,地下水位动态具有周期性。     

湛江市地下水流场演变特征

文章研究了湛江市50年来的地下水流场变化特征，得出以下结论：市区中、深层承压水经过近50年的集中开采．已形成了以人工开采区为中心的区域水位降落漏斗；浅层水一直未作为集中供水水源，未形成区域水位降落漏斗。影响地下水流场变化的因素主要为开采量，其次为地下水的开采方式及水文地质条件。     

江苏南通地下水补给源、水化学特征及形成机理

在地下水的大规模开采条件下,江苏沿海一带,特别是南通许多地区的地下水一度出现咸化趋势,对区域水资源及环境产生了极大的影响,已成为制约生态环境建设和经济社会发展的重要因素.为查明地下水的补给来源、水化学特征和矿化度增高的机理,对南通地区深浅层地下水开展了野外调查取样.通过对各种水化学参数的讨论分析,系统地研究了该区地下水...     

鲁北平原地下水的劣变特征与可持续利用的对策

2005年相对于20世纪70年代,鲁北平原开采机井数由9．29万眼增至28．76万眼．浅层水、深层水开采量分别增加了近2倍和3．76倍。长期超量开采和不合理的开采布局,使地下水水位持续下降、含水层疏干体积不断增加、地下水位降落漏斗持续扩展．并产生地面沉降、成水入侵等环境地质问题。采取农业节水、调整工业开采强度布局、加强浅层水均衡开发利用、地表水与地下水联合调蓄、本地劣质水资源化、保护和涵养深层地下水资源等举措,修复和涵养鲁北平原超采区的深层地下水系统势在必行。     

江苏省地下水开发利用中的环境地质问题及对策

江苏省地下水在开发利用过程中,由于开采布局不合理和存在＂三集中＂以及水文环境地质条件脆弱等因素,出现水位逐年下降,并形成区域性超采漏斗,致使部分地段地下水资源枯竭、水质咸化和诱发地面沉降、地裂缝、岩溶塌陷等诸多环境地质问题。本文着重分析全省深层地下水开发利用的四个阶段、主采层区域水位降落漏斗的发展过程和因深层水超量开采诱发的水资源枯竭、水质咸化和地面沉降、地裂缝、岩溶塌陷等环境地质问题的发育特征及演化趋势,从地下水资源管理和可持续发展的角度,提出地下水资源合理利用的对策建议。     

湛江市深层承压水铁分布和地球化学模拟研究

在广东省湛江市深层承压水开采过程中,在开采区内形成了区域水位降落漏斗。降落漏斗的形成对深层承压水的化学特性产生了一些影响,具体表现为：西部和西北部铁含量低,北部铁含量高,降落漏斗附近铁含量中等。对降落漏斗内深层承压水铁分布进行演化模拟计算,结果表明,降落漏斗内深层承压水的补给可能来自北部高铁承压水、西部和西北部低铁承压水以及浅层承压水。深层承压水由这些地下水混合而成,高铁地下水是主要补给来源。降落漏斗中心区深层承压水的大量人工开采导致其铁含量升高。地下水在向降落漏斗中心区的径流过程中,不但发生了方解石、白云石和赤铁矿的溶解作用以及菱铁矿和水绿矾的沉淀作用,而且发生了Na⁺与Ca²⁺的交换、铁氧化-还原反应等一系列复杂的水-岩作用。     

兖州煤田奥陶系灰岩地下水水化学特征及其形成机理

鲁西南兖州煤田的奥陶系灰岩地下水对煤田深部煤炭开采具有潜在的水害威胁,且为研究区的主要供水水源之一,其水化学特征及形成机理分析,可为该区深部煤炭开采水害防治和地下水资源利用提供依据。经过目的层水样的采集与测试可知,地下水水化学类型以SO_4-Ca-Mg型为主,SO_4~(2-)含量为537~2 296 mg/L,Ca~(2+)和Mg~(2+)的平均含量分别为455.7 mg/L和116.6 mg/L,TDS的范围为961~3 555 mg/L,pH值为6.9~8.0。Ca~(2+)和SO_4~(2-)随TDS的增加而增加,呈良好线性关系,推断TDS的增加主要来自Ca~(2+)和SO_4~(2-)的贡献。由饱和指数(SI)可知,地下水中的白云石和方解石均处于过饱和状态,而绝大部分的水样的石膏饱和指数均小于0,处于不饱和状态。石膏的饱和指数与地下水中TDS呈正相关关系。这些结果表明,在该含水层中地下水运移过程中不断发生水岩相互作用,主要包括石膏溶解、白云石和方解石沉淀或溶解、离子交换等反应。     

深层水漏斗区开采量组成变化特征与机制

为阐明强烈开采条件下华北平原深层水的开采水量来源及组成问题,以德州地区深层水漏斗分布区为重点研究区,通过基于大量钻孔资料对含水层组及其粘性土夹层或透镜体的分析和野外地下水采样、动态监测及地面沉降测量资料等分析,采用分层、分区计算方法对漏斗中心至外围的各分区弹性释水量、粘性土压密释水量、侧向流入和越流补给量进行均衡计算。结果表明:在强烈开采条件下,深层水开采量中弹性释水量和压密释水量所占比率不是常量,随着深层水位下降的幅度和深度增大、超采释压持续时间愈长、开采层中粘性土夹层或透镜体愈多,则区内弹性释水和压密释水的强度及累积地面沉降量愈大;愈靠近漏斗中心,弹性和压密释水强度愈大,相同降深下平均单位降深的地面沉降量愈小。在深层水开采量中粘性土压密释水占35.5%~61.9%,与地面沉降密切相关。     

Study on the groundwater sustainable problem by numerical simulation in a multi-layered coastal aquifer system of Zhanjiang,China

Assessing sustainability of coastal groundwater is significant for groundwater management as coastal groundwater is vulnerable to over-exploitation and contamination. To address the issues of serious groundwater level drawdown and potential seawater intrusion risk of a multi-layered coastal aquifer system in Zhanjiang, China, this paper presents a numerical modelling study to research groundwater sustainability of this aquifer system. The transient modelling results show that the groundwater budget was negative (\(-3826\times 10^{4}\) to \(-4502\times 10^{4 }\,\hbox {m}^{3}/\hbox {a}\)) during the years 2008–2011, revealing that this aquifer system was over-exploited. Meanwhile, the groundwater sustainability was assessed by evaluating the negative hydraulic pressure area (NHPA) of the unconfined aquifer and the groundwater level dynamic and flow velocity of the offshore boundaries of the confined aquifers. The results demonstrate that the Nansan Island is most influenced by NHPA and that the local groundwater should not be exploited. The results also suggest that, with the current groundwater exploitation scheme, the sustainable yield should be \(1.784\times 10^{8}\, \hbox {m}^{3}/\hbox {a}\) (i.e., decreased by 20% from the current exploitation amount). To satisfy public water demands, the 20% decrease of the exploitation amount can be offset by the groundwater sourced from the Taiping groundwater resource field. These results provide valuable guidance for groundwater management of Zhanjiang.     

Occurrence and evolution of the Xiaotangshan hot spring in Beijing, China

Thermal groundwater occurs in bedrock aquifers consisting of the dolomite of the Wumishan Group of the Jixianin System and the Cambrian carbonate in the Xiaotangshan geothermal field near the northern margin of the North China Plain, China. The hot water in the geothermal field of basin-type discharges partly in the form of the Xiaotangshan hot spring under natural conditions. The hot water has TDS of less than 600 mg/L and is of Na·Ca-HCO₃ type. The geothermal water receives recharge from precipitation in the mountain area with elevation of about 500 m above sea level to the north of the spring. Thermal groundwater flows slowly south and southeast through a deep circulation with a residence time of 224 years estimated with the Ra–Rn method. The Xiaotangshan hot spring dried up in the middle of the 1980s owing to the increasing withdrawal of the hot water in the geothermal field in the past decades. The water level of the geothermal system still falls continually at an annual average rate of about 2 m, although water temperature changes very little, indicating that the recharge of such a geothermal system of basin-type is limited. Over-exploitation has a dramatic impact on the geothermal system, and reduction in exploitation and reinjection are required for the sustainable usage of the hot water.     

基于典型钻孔的江汉平原地下水成因分析

江汉平原地下水需求量日益增加、水质持续恶化,深入探究地下水的成因,对于地下水的合理利用与评价具有重要意义.选取江汉平原腹地YLW01钻孔和汉江附近HJ007钻孔为研究对象,钻探采集原状土柱,提取孔隙水,分析其水化学和氘氧同位素特征.研究表明:YLW01孔中深层砂性土孔隙水为咸水,TDS为1 131~4 013 mg/L,粘性土孔隙水为淡水;HJ007孔孔隙水均为淡水.YLW01孔中深层砂性土孔隙水的高SO₄2-含量（459~2 124 mg/L）,由石膏溶解形成;HJ007孔中深层孔隙水的高NO₃-含量（22~315 mg/L）,由土壤中硝化作用形成.孔隙水化学成分主要受矿物溶解和阳离子交替吸附作用影响,在长江和汉江带作用程度不同.氘氧同位素特征表明孔隙水来源于大气降水,且汉江带浅层地下水受到明显的地表水混合.江汉平原两个钻孔水化学与同位素的差异受长江和汉江影响带河湖相沉积环境、沉积物粒度及矿物组成所控制.      

雷州半岛防海水入侵最优地下水开采方案探讨

雷州半岛地表水资源缺乏 ,地下水资源较丰富 ,近年开采量剧增 ,局部已形成大面积降落漏斗 ,面临海水入侵的威胁。通过对研究区内地下水流的数值模拟 ,建立了一个以预防海水入侵为目的的地下水资源管理模型 ,并以管理区为单元给出了不同区域地下水资源的最优开采量。认为在防止海水入侵的前提下 ,区内地下水总体上尚有开采潜力 ,但要适当分散开采区域 ,滨岸地区基本维持现状 ,内陆可不同程度地增大开采量。     

基于人工神经网络的地下水状态方程—以山东莱州湾南岸地下水研究为例

山东莱州湾南岸地下水密度受多种因素影响,传统方法难以拟合,利用人工神经网络（简称ANN）高效的自组织学习能力和抗实验噪音能力及应用神经网络工具箱设计了三层反馈式神经网络模型,得出映射莱州湾南岸地下水密度与含盐量之间相关关系的基于ANN的地下水状态性关系的性质,基于ANN的地下水状态方程具有形式简单,易于使用等特点。     

Radiocarbon evidence of paleo-recharge (pre-Saraswati period) of potential deep aquifer in Thar desert

The Oil and Natural Gas Corporation Limited (ONGC), India, embarked upon exploration and exploitation of deep groundwater under the project named as “Saraswati” in arid Thar desert, Rajasthan, with a societal mission of providing water to the local people and cattle. A 555 m deep well drilled by the ONGC near Jaisalmer town in 2006 encountered a potential aquifer at a depth of 450–500 m. Radiocarbon dating of this well water indicated paleorecharge to be >40,000 yr BP (uncorrected) (Before Present with respect to 1950 AD), while the medium depth (∼200 m) well waters around that area showed an age range of ∼9,000 to 17,000 yr BP (uncorrected). These waters represent pre-Saraswati era recharge, because the mighty Saraswati flowed in this region between 7000–4000 yr BP. The stable isotope (δD and δ¹⁸O) and Total Dissolved Solids (TDS) data of these waters clearly indicated absence of communication between the two aquifers (deep and medium depth). However, the extension of this deep aquifer needs to be determined.     

Groundwater flow rate and contaminant migration in fissure-karstic aquifer of Opole Triassic system southwest Poland

 This paper presents hydrogeological problems occurring during municipal water exploitation and mine dewatering. These activities result in groundwater quantity and quality changes in the fissure-karstic aquifer. Increase of nitrate concentration up to 12 mg NNO₃/l due to intensive fertilizer use, and high tritium concentration, show water system impact up to 100 m depth. Intensive water exploitation produces large cones of depression with over 40-m water-level depletion in the Opole region. Flow rates of major components and isotopes have been verified by chemical migration history. Some aspects of the protection policy of this type of aquifer are also discussed. Received: 7 March 1997 · Accepted: 17 November 1998     

福州温泉区地下热水开采与水位动态响应研究

地下热水是一种极其宝贵的资源，然而长时间的过量开采，使资源濒临枯竭，同时还会产生一系列的环境负效应。福州温泉区蕴藏着丰富的地下热水，多年开采，水位不断下降，已使部分泉消失。针对这一状况，笔者对福州温泉区地下双层热储层——第四系孔隙热储层及下伏基岩裂隙热储层中热水的赋存条件，补给与排泄条件，开采的历史与现状，热储层历年地下水位动态变化特征及漏斗展布状况进行了详细的对比分析与研究。研究结果显示第四系孔隙热储层北部抽水漏斗较深，南部补给相对充分而漏斗不明显，经过10a的变化漏斗中心最大变化幅度为7．6m；基岩裂隙热储层出现南北2个漏斗，10a间漏斗中心水位最大变化幅度为12．61m。表明随着开采的进行，地下热水水位在持续性下降，热资源在逐渐流失。指出加强地热资源开采量监控及建立比较完善的地热资源管理系统的迫切性，以实现资源的合理利用和可持续发展。     

鲁西南地区高氟水分布规律与成因分析

地方性氟中毒是我国北方地区最为典型的地方病之一,查明高氟地下水的空间分布及其成因是除氟改水、防治氟害的前提。通过对鲁西南地区不同层位地下水水质分析结果及水文地质、地质条件等多个环境影响因素的综合分析,查明了鲁西南地区高氟水的空间分布规律,并分析了影响浅层和深层高氟水形成的环境因素。浅层高氟水呈片状分布于洼地、缓平坡地等地势较低的区域,占鲁西南地区总面积的47%,大部分地区高氟水氟离子含量为1.2～2.0 mg/L,局部大于4.0 mg/L,其形成受气候、地质环境、地形地貌特征及水化学环境等多个因素的影响,成因类型为溶滤-蒸发浓缩型。深层高氟水具有水平分带性,占鲁西南地区总面积的65%,大部分高氟水氟离子含量为2.0～4.0 mg/L,氟离子含量分布与晚更新世沉积相带呈现很好的相似性,推测其为地质历史时期形成的古地下水。     

Hydrogeochemical transport modeling of the infiltration of tertiary treated wastewater in a dune area, Belgium

Managed artificial recharge (MAR) is a well-established practice for augmentation of depleted groundwater resources or for environmental benefit. At the St-André MAR site in the Belgian dune area, groundwater resources are optimised through re-use of highly treated wastewater by means of infiltration ponds. The very high quality of the infiltration water sets this system apart from other MAR systems. The low total dissolved solid (TDS) content in the infiltration water (less than 50 mg/L) compared to the dune aquifer (500 mg/L) triggers a number of reactions, increasing the TDS through soil-aquifer passage. Multi-component reactive transport modelling was applied to analyse the geochemical processes that occur. Carbonate dissolution is the main process increasing the TDS of the infiltration water. Oxic aquifer conditions prevail between the infiltration ponds and the extraction wells. This is driven by the high flow velocities, leaving no time to consume O₂ between the ponds and extraction wells. Cation exchange is important when infiltration water is replaced by native dune water or when significant changes in infiltration-water quality occur. The seasonal variation of O₂ and temperature in the infiltration water are the main drivers for seasonal changes in the concentration of all major ions.     

Optimal Groundwater Development in Coastal Aquifers Near Beihai, China

INTRODUCTIONThe city of Beihai,located on the south coast ofGuangxi,China,relies heavily on groundwater for its potablewater supply and agricultural irrigation.With rapid increasein population (for instance,from 134 0 0 0 in 1987to 47930 0in1995 ) and in developm ent program s,the demand for freshwater has been growing. Approxim ately 170 0 0 0 m3/ d ofgroundwater has been pumped from the productive coastalaquifers in recent years.Contamination of the fresh water inthe coastal aquifers b…