阜阳高氟地下水形成的地质环境浅析

阜阳市松散岩土含水系统广泛赋存着高氟地下水,氟含量一般在１．０～３．８０ｍｇ／ｌ最高可达６．９０ｍｇ／ｌ,本文通过对高氟地下水赋存的地质环境及地球化学特征等综合分析,认为本区高氟水的形成与其赋存的地球化学环境及水动力条件密切相关。     

高氟地下水混凝沉淀降氟试验研究

本文开展了山西运城地区高氟地下水的降氟试验,对聚铁、硫酸铝和明矾等不同混凝剂降氟效果进行对比,探讨了地下水硬度对混凝沉淀除氟效果的影响.实验结果表明:明矾混凝沉降效果优于其它混凝剂,0.3g/L的明矾溶液可使含氟浓度4.0mg/L 的地下水降低到浓度1.0mg/L以下;地下水的硬度对明矾混凝降氟效果没有明显影响.     

北京小汤山地区第四系高氟地下水与地热水关系研究

北京小汤山地区第四系深层地下水氟含量普遍超标, 严重制约区域供水。在收集整理基础地质、水文地质、地热地质资料基础上, 开展第四系高氟地下水与地热水之间关系研究工作。研究表明: 小汤山地区位于复式背斜的核部区域, 该区热储层与第四系地层直接接触并形成水力“天窗”, 受构造应力影响在热储层发育大量张性裂隙, 加之上覆第四系盖层结构松散且厚度较薄, 导致该区成为地热富集带; 在高温高压环境下, 地热水中氟化物含量普遍较高, 地热水上涌同第四系深层地下水发生热流-冷流的混合作用, 导致第四系深层地下水中氟化物含量升高, 形成第四系高氟地下水。     

河北平原第四系水土中氟的地球化学研究

通过岩土孔隙溶溶成分，岩土及及含氟矿物的淋溶、浸泡实验和土柱试验，揭示了河北平原第四系水土中氟的地球化学特征；并用Ｐｈｒｅｅｑｅ软件对６种水－岩相互作用系统中氟的水文地球化学进行了模拟。     

高氟土壤的氟动力学吸附试验研究

通过室内水土试验,研究山东高密高氟地区的土壤对氟的动力学吸附特性,并用典型的低氟土试验进行对比。从化学动力学的角度讨论高氟土壤对氟的吸附行为。高氟土壤对氟的吸附有其特殊性;高氟土壤对氟的吸附分为快、慢两个阶段;羟基是影响氟吸附的重要因素。     

陕西定边平原高氟地下水的形成、分布及改水途径研究

定边平原高氟地下水的形成,受控于地质环境、气候、地貌和水化学条件等;成因可分为溶滤型、浓缩型和溶滤一浓缩型。其水平分布规律,受地貌、地质和水文地质条件的控制。防氟改水方法,要因地制宜,灵活多样,综合改水;应采取打井和打窖相结合,分散供水与集中供水相结合,引水与理化除氟相结合。     

贵州高氟地下水的分类特征及其形成机理

根据贵州高氟地下水的水化学特征，结合其水文地质和岩石条件等，将其分成两种主要类型，即碳酸盐岩区的高氟地下水和硅质陆源碎屑岩（含浅变硅质陆源碎屑岩）区的高氟地下水，按水－岩作用的机理，探讨了高氟地下水水化学特征形成的地球化学机制。     

德州市高氟深层地下水分布特征及饮水安全措施

作为德州市农村主要饮用水源之一的深层地下水氟化物含量超标,严重影响了当地人民群众的身体健康。本文对德州市高氟深层地下水的分布及成因进行了分析,阐述了饮用高氟水的危害,结合当地做法对降氟改水措施做了探讨。     

苏锡常地区地下水禁采后的地质环境效应研究

1995年以来,针对严重的区域性地面沉降和地裂缝灾害,苏锡常地区地下水资源保护和管理工作逐渐加强,特别是从2000年开始,江苏省政府分阶段实施限期禁止开采工作,首先在超采区实行地下水禁采,到2005年底,在苏锡常地区全面禁止开采地下水,全区地下水环境、地面沉降状况出现明显好转,地下水水位普遍回升,地面沉降速率逐渐减缓。根据近年来苏锡常地区地面沉降基岩标、分层标的系统监测资料,对地下水禁采后地质环境的效应特别是地面沉降的变化特征进行了初步分析、研究,并对该区今后地质环境保护工作提出了对策和建议。     

延庆盆地地下水水化学特征统计分析

基于2008年枯水期地下水采样数据共计65个样本点,对水质组分进行了分层统计,并进行了地下水质量评价。此外,开展了TDS、Ca2＋、NO3-和硬度与取样深度的相关性分析。结果表明,垂向上,延庆盆地地下水由浅到深,地下水水质逐渐变好;横向上,上游地下水水质好于中游,中游好于下游;深层地下水已经出现较差和极差点。     

鲁中南基岩地区水文地质特征及地下水环境地质问题分析

基于在鲁中南低山丘陵基岩地区开展的1∶5万水文地质调查工作,通过水文地质调查、水文地质钻探、地球物理勘探、抽水试验、水质分析等技术方法,分析该区水文地质特征。研究结果表明：区内地下水类型划分为松散岩类孔隙水、碎屑岩类孔隙裂隙水、碳酸盐岩类裂隙岩溶水以及基岩裂隙水4类,并总结了其含水岩组富水性;分析了地下水补给、径流、排泄条件及其演化以及环境水文地质问题。圈定了有集中供水意义的第四系孔隙水富水地段3处,总结了地层阻水型蓄水构造和断层储水构造2种基岩蓄水构造类型。区内地下水质量以Ⅲ类、Ⅳ类和Ⅴ类为主,超过Ⅲ类水标准的组分主要是硝酸盐、总硬度、铁,其次为氟化物等。利用总结的区内找水模型,共施工具有供水意义的水文地质钻孔10眼,总涌水量7017.84 m³/d,可解决近10万人生活和5900多亩农田灌溉用水问题。对于寻找新的供水目标含水层及找水定井工作具有指导意义。     

Barometric pumping effects on soil gas studies for geological and environmental characterization

Data from two free soil gas sampling programs are evaluated for the effects of barometric pumping over time on measured soil gas volumes. One program collected data from the trapped atmosphere immediately above two hazardous waste landfill areas. Of these areas, one had extremely high soil gas emanations, whereas the other had a more modest soil gas release. The second experimental program involved the collection of free soil gas samples on a rough grid with an approximate spacing of 1.6 km over a 720-sq-km area. This reconnaissance effort was designed to establish regional soil gas background values and to establish the utility of this method as a geological mapping tool in the Atlantic Coastal Plain. Methane, ethane, propane, and hydrogen data are used for this study. The data suggest that there is a predictable change in soil gas volume with a given change in barometric pressure. The rate of change is greater with large soil gas volumes in permeable soils versus lower soil gas volumes in impermeable soils; however, a simple linear relationship seems to generate a predictable curve with a margin of error of approximately 50%. Furthermore, the results of this study indicate that barometric pumping effects should be strongly considered during soil gas screening efforts at hazardous waste sites as well as in regional studies for hydrocarbon source potential mapping.     

Erratum to: Geochemical and environmental magnetic characteristics of high arsenic aquifer sediments from Datong Basin,northern China

Geochemical and environmental magnetic studies were carried out to identify the effect of iron oxyhydroxides on arsenic mobilization in high arsenic aquifer system. Using high arsenic sediment samples from two boreholes, specifically drilled for this study, chemical composition and magnetic properties including magnetic susceptibility, saturation remnant magnetization, and isothermal remnant magnetization were measured. Results of correlation analysis of element contents show that arsenic and iron are closely associated with each other (r ² = 0.40, α = 0.05, n = 21). In contrast, the correlation of phosphorus with iron (r = 0.11, α = 0.05, n = 21) and arsenic (r ² = 0.18, α = 0.05, n = 21) was poor, which might result from competitive adsorption of phosphorus and arsenic on the surface of Fe-oxyhydroxides. The high correlation coefficients between arsenic contents and magnetic parameters suggest that the ferrimagnetic minerals including maghemite and hematite are the dominant carrier of arsenic in aquifer sediments. The results of sequential extraction experiments also revealed the association of arsenic with reducible iron oxides, such as maghemite and hematite in aquifer sediments. Therefore, under reducing conditions, reductive dissolution and desorption of arsenic from Fe-oxyhydroxides into the aqueous phase should be the dominant geochemical processes for its enrichment in groundwater at Datong. An erratum to this article can be found at     

Hydrogeochemical zonation for groundwater management in the area with diversified geological and land-use setup

Despite its limited aerial extent, the National Capital Territory (NCT) Delhi, India, has diversified geological and topographical setup. A geochemical assessment of prevailing conditions of aquifer underlying the NCT was attempted and further classified into different hydrogeochemical zones on the basis of statistical and analyses and its correlation with land use, geological and climatic setting. Mineral phase study and isotopic analyses were used for the verification of performed clustering. Saturation indices (SI) calculated using the geochemical modelling code PHREEQC were used to distinguish the characteristics of four zones, as saturation states of the water does not change abruptly. Four different hydrogeochemical zones were statistically identified in the area: (1) intermediate (land-use-change-impacted) recharge zone, (2) discharge (agriculture-impacted) zone, (3) recharge (ridge) zone, and (4) recharge floodplain (untreated-discharge-impacted) zone. The distinctiveness of hydro-geochemical zones was further verified using stable isotopic (²H and ¹⁸O) signature of these waters. GIS-based flow regime in association with long-term geochemical evidences implied that these zones are being affected by different problems; thus, it necessitates separate environmental measures for their management and conservation. The study suggested that in a diversified urban setup where the complex interactions between anthropogenic activities and normal geochemical processes are functioning, hydrogeochmical zoning based on the integration of various techniques could be the first step towards sketching out the groundwater management plan.     

Response of the interaction between groundwater and other components of the environment in Mexico

This article reviews and discusses environmental aspects related to vertical upward and downward groundwater flow. Flow systems are an important tool to understand groundwater functioning as related to the environment, in terms of obtaining indicators of human impact and solving specific questions about a groundwater-environment system that has been influenced by anthropogenic means. This involves two broad processes. First, groundwater changes due to activities of man in the surrounding environment as a result of: (1) alteration of recharge by modification of native vegetation and original soil cover; (2) reduction of groundwater discharge to coastal areas and to inland water bodies producing desiccation of wetlands, lakes and springs; (3) groundwater contamination from sewage looses and uncontrolled waste disposal locations, and (4) up-welling of undesirable water quality induced by extraction. Second, environmental alterations due to changes in the groundwater regime produce: (1) increase in soil erosion through the disappearance of vegetation due to water-table decline, (2) water-table rise due to unplanned artificial recharge resulting from water imports to a catchment, (3) decline in water levels for improper extraction regime, (4) soil subsidence due to extraction mismanagement, and (5) disappearance of phreatofites caused by excessive extraction. Unless further understanding between groundwater and the other components of the environment is sought, the relationship between people and its environment will be subject to some of these effects, potentially endangering adequate human development and sustainable water management.     

长江经济带环境地质调查研究进展

中国地质调查局近年组织实施了"长江经济带地质环境综合调查工程",采用环境地质调查、评价、监测以及专题研究和综合研究相结合等方法,取得了一批重要的成果和认识: ① 构建了长江经济带地质资源环境综合信息管理与服务系统,系统梳理了长江经济带与重点区域的资源环境条件和重大地质问题,提出了相关建议;② 提出长江续接贯通时间是在距今75万年的早、中更新世之交的新认识;③ 探索形成流域5个系列生态修复示范关键技术和方法体系;④ 构建长江流域重大水利工程与地质环境效应研究方法体系,创建一套多模态传感器系统,提出重大水利工程对地质环境影响的新判断;⑤ 探索建立流域尺度地球关键带调查评价监测理论和方法体系;⑥ 创新应用"光纤技术"监测地面沉降和地裂缝、长江崩岸以及城镇地下空间开发利用扰动取得突破,相关技术引领光纤监测技术发展;⑦ 自主研发机载航空高光谱仪,建立航空高光谱遥感综合调查技术方法;⑧ 探索形成流域3种尺度资源环境承载能力和8种国土空间开发利用适宜性评价方法体系;⑨ 调查研究成果在支撑服务长江经济带国土空间规划、流域生态环境保护和修复、支撑服务新型城镇化战略、重大工程规划建设、地质灾害防治、脱贫攻坚和国家地下战略储油储气库基地建设等方面均得到了广泛应用,形成21支稳定的环境地质调查专业团队。     

官厅水库浸没问题对延庆规划新城的影响分析研究

通过对官厅水库浸没资料的分析研究,结合水库浸没危害的各项影响因素,分别采用数值模拟法和地下水动力学法,建立库区水文地质模型,模拟计算未来库水位抬高后两岸地下水位的变化,预测浸没范围和危害程度。经分析,目前官厅水库对延庆规划新城无浸没危害;当库水位达到或超过471.4m时,规划新城西侧将会受到浸没问题的影响,危害程度轻微;当库水位达475.2m时,工程建设规划区将会产生浸没问题,危害程度轻微。当库水位达设计高水位479m时,规划新城区3/4以上区域、规划建设区一半以上区域属于浸没区,危害程度轻微—严重不等。     

中国矿山环境地质问题区域分布特征

为了了解中国不同区域矿产资源开发产生的主要环境地质问题分布特征,为矿山生态环境恢复治理规划提供基础资料。笔者依据近几年全国矿山地质环境调查成果资料,首次对全国矿山地质环境区进行了系统划分和地质环境条件分析,通过研究不同地质环境区开发的主要矿产资源类型、开发强度、不同类型矿产开采产生的主要环境地质问题类型、分布、危害、需要防治的主要环境地质问题,对矿山开发产生的土地占用与破坏、地质灾害、环境污染的区域分布特征进行了总结。结果表明,中国中东部地区矿产资源开发强度、矿山环境地质问题重于西部地区,煤矿山问题重于金属矿山、金属矿山问题重于非金属矿山。