含水层结构变异对区域地下水循环影响数值模拟

煤炭开采对地下水资源的破坏是限制煤矿区经济与环境可持续发展的主要瓶颈, 煤炭资源开采与水资源保护的矛盾将日益加剧。我国富煤地区主要分布在华北和西北, 仅山西、内蒙古、陕西和新疆四省自治区煤炭查明资源储量就占全国的73.1%, 这些富煤地区多是地下水资源相对贫乏的地区, 全国86个重点矿区缺水的占71%, 严重缺水的占40%, 而煤矿开采对地下水资源的严重破坏加剧了矿区的水资源短缺矛盾, 这一问题在能源大省山西尤为突出。究其根本原因, 在于采煤引起含水层结构变化, 造成地下水资源的破坏, 使地下水资源由原来可供开采的优质水源变为被污染的矿坑水而排走, 破坏了地下水的补径排, 破坏了水文下垫面条件, 破坏了地表水循环, 进而影响了区域地下水循环态势。     

煤区岩溶地下水污染模式及特征研究——以黔西盘关向斜区域为例

煤企生产过程中产生的废水是造成地下水污染的主要因素。通过环境水文地质调查,对盘关向斜区域煤企生产活动造成地下水污染的主要方式进行分析,查明区内主要污染源—煤矿污水、洗煤水及堆场淋滤水通过地表水体、溶隙、落水洞等途径进入岩溶含水层污染地下水,又经岩溶管道长途运移排泄至地表,造成暗河出口地表河流污染的污染模式。其污染的三种基本模式为地表水体污染、包气带污染以及地下水污染。针对煤区岩溶地下水污染表现的滞后性和周期性,提出煤区岩溶地下水污染防治对策,对区内环境保护工作具有一定参考价值。     

包气带—含水层地下水污染风险评估研究进展

包气带—含水层作为地表水和地下水之间水循环和溶质迁移的重要介质,是地球科学领域中的研究热点。以包气带—含水层中地下水污染风险评估为综述对象,从包气带—含水层地下水污染现状出发,总结了包气带—含水层的污染现状、表征、渗流与溶质迁移及其影响关键参数研究等方面的进展,最后分析包气带—含水层地下水污染风险评估存在的问题及今后的研究方向,指出尤其应重点考虑基于逾渗阈值开展地下水污染风险评估研究。     

云南丽江盆地地下水系统边界研究及系统划分

丽江盆地地下水循环状况对解决黑龙潭断流这一重大环境地质问题具有指导性作用.丽江盆地及周围地下水系统的划分是这一研究工作的基础.本文采用的系统边界包括流域界线、构造边界、地貌边界、阻水边界及排泄边界等.通过综合分析地表分水岭、含水层组、可溶岩与非可溶岩边界、断层性质等,确定系统边界,划分了一级至二级地下水系统,并着重分析...     

豫北平原地下水开采对环境的影响

在介绍了豫北平原地下水开采的历史与现状的基础上,对开采地下水所带来的环境正负效应进行了分析.豫北平原地下水的开采对环境的影响属于正效应的主要有加快水循环,促进洪水资源化;减弱旱灾影响,保证供水安全;促进水质淡化和土壤改良等;属于负效应的主要有造成泉消失、湿地面积萎缩;地面沉降;加剧地下水水质的污染等.     

硝酸盐污染地下水中溶解性有机质光谱特征及其指示意义:以鄂尔多斯盆地北部湖泊集中区为例

水资源短缺的西北干旱-半干旱地区,作为重要供水水源的地下水遭受硝酸盐等污染问题日益突出。识别地下水硝酸盐来源及其迁移转化过程对于污染防治至关重要。溶解性有机质(DOM)及其组分特征对于硝酸盐的迁移转化有着重要影响,因此,探究DOM组成特征与地下水硝酸盐污染相关性显得尤为必要。以鄂尔多斯盆地北部湖泊集中区作为研究区,运用紫外-可见光光谱技术和荧光光谱技术手段,表征了硝酸盐污染地下水中DOM的组成特性,分析了地下水硝酸盐污染成因。结果表明,研究区深度400 m以上的地下水受到不同程度的硝酸盐污染,其主要是由于农牧业活动和生活污水等产生硝酸盐污染,同时质地疏松的沙质土包气带有利于地表污染渗入地下水中。此外,地下水中DOM主要来源于地表,使得反硝化作用较弱,不利于地下水中NO~-_3的自然衰减。     

黄龙核心景区多层级水循环系统结构研究

为查明四川黄龙核心景区钙华层内水体的循环交替过程及水循环系统结构,采用野外实地调查、水循环断面监测等方法,分析任一监测断面的地下水径流量和地表水流量(二次转化泉形成)组成、循环段内的补给和排泄特征,理清各水循环系统的发育规模、层级.分析结果表明,丰水期水循环系统层级最为复杂,分为区域-局部-场地三个循环层级,以局部循环...     

岩溶地区矿井水环境影响及防治对策探讨

岩溶地区矿井水对环境的影响复杂,它不仅对地表水体产生不利影响,而且由于落水洞、地下河发育,地下水体与地表水体之间水力联系密切,若矿井水若处置不当,还将对地下水环境产生不利影响.以典型的岩溶地区——贵州省金沙县为例,通过收集目前正常生产的部分矿井水水质资料,调查区域的基本水文状况,认为研究区地表水体规模普遍较小,落水洞、暗河等较为发育,地表水体与地下水体之间的水力联系较为密切,矿井水不仅容易污染地表水,而且容易对地下水产生不利影响.针对其影响方式、范围、程度及特点提出了源头控制、源头控制、矿井水资源化、优化排放方式等一系列的综合防治对策,以供类似地区矿井水的污染防治参考.     

地下水循环结构的动力学研究进展

由地下水补给、径流和排泄过程构成的地下水循环运动,是水文循环的重要组成部分,也是水文地质学的基本研究对象.地下水循环在空间上表现为不同结构单元的组合,存在以含水层特性为依据的介质结构和以渗流场为依据的动力结构2种划分方法.地下水流系统是动力结构意义上的地下水循环单元.近10年来,区域地下水流系统理论取得了显著进展,更加全面深入地揭示了地下水循环结构的动力学特性.通过对河间地块地下水流系统的研究,发现潜水面最高点并非地下水分水岭的准确位置.在盆地尺度上,系统研究了沟谷地貌、降水入渗强度、渗透性随埋深变化和盆地厚度等因素对潜水面波形与地下水循环动力结构的影响,初步发现了动力结构的周期性或趋势性演化特征.通过大规模流线路径的精细识别或驻留时间的统计分析,提出了三维地下水循环单元的划分方法.在水文地质效应方面,发现地下水循环的动力结构对地下水年龄的分布有重要影响.地下水循环的动力结构反映了不同补给区和排泄区之间的水力联系,在盆地尺度地球化学过程、流域尺度生态水文过程中发挥着关键作用,未来的研究重点是三维地下水循环的动力特性和演变规律.     

大庆市地下水石油类系统形成机制研究

本文以大庆市具有代表性的纳污湖泡－贴不贴泡区地下水石油类污染系统为研究对象,通过对其进行成因分析,提出地下水石油类污染系统是石油质以下地水循环系统为载体,在水动力场,水化学场的共同作用下形成的。     

淮南采煤沉陷区积水来源的氢氧稳定同位素证据

淮南是我国东部重要的能源基地,由于长期地下采煤,地表形成大面积的采煤沉陷区并积水,造成严重地质灾害。针对于此,部分学者提出利用采煤沉陷区建立"平原水库"解决周边地区干旱年份农田缺水问题的设想。然而,一方面,由于煤层上覆几百米厚的新生代沉积,采煤塌陷形成的沉陷裂隙是否沟通了不同含水层之间的水力联系,并因此改变了这个地区的地下水系统,成为区域水资源评价需要了解的一个重要科学问题;另一方面,建立"平原水库"需要有稳定的补给水源,采煤形成的沉陷裂隙如果沟通了地下不同深度含水层的水力联系,是否使地下水成为塌陷区除降雨外的重要补给来源,这就成为评价"平原水库"水资源潜力的重要参考依据。氢氧稳定同位素是示踪天然水体水来源的重要手段,笔者在淮南矿区采集了旱季和雨季的浅层地下水、河水、雨水、沉陷区的积水等不同水体的水样23件,分析了其氢氧稳定同位素组成并与深层地下水进行对比。结果表明:雨季和旱季,该地区采煤沉陷区积水的氢氧稳定同位素组成都非常接近大气降水的氢氧稳定同位素组成,而与深层地下水的氢氧稳定同位素组成相差较大,说明采煤沉陷区的积水来源主要是大气降水补给。采煤沉陷区的沉陷裂隙贯穿了整个新生代地层,使地表水发生下渗与在深部与深层地下水发生不同程度的混合,而深层地下水尚不是"平原水库"的稳定补给源。     

Nitrate contamination in a shallow urban aquifer in East Ukraine: evidence from hydrochemical,stable isotopes of nitrate and land use analysis

A combined hydrochemical and stable isotope approach was used to investigate the origin of nitrate in the shallow unconfined groundwater of Kharkiv city, Eastern Ukraine. The contamination was investigated in the context of land use within the catchment area. The observed enrichment of sulfate, chloride and nitrate suggests significant groundwater contamination in the shallow urban aquifer, which is widely used as drinking water source for the urban population. Characteristic nitrate/chloride ratios as well as stable isotope ratios (N and O) of nitrate in the most contaminated springs confirmed that septic waste from leaky sewer systems was the main source of nitrate contamination in the groundwater. Nitrate contamination is linked to the type of land use and sewage treatment regime in the catchment area. It is also modulated by the regional hydrogeology, which determines the susceptibility of a given aquifer toward groundwater pollution. A more quantitative assessment of nitrate sources based on the nitrate isotope analysis alone is rather difficult. However, our study confirms that the combination of hydrochemical tracers, robust land-use analysis and nitrate stable isotope measurements represents a valuable approach to identify the origin of the nitrate contamination.     

应用环境同位素分析吉林市松花江水与地下水的联系

水的环境同位素可以用来研究地下水的来源、地表水和地下水的关系,进而间接判断水质的相互影响.通过松花江吉林市江段两条剖面的氘、氚、氧同位素特征分析,结合水化学及水文地质条件,阐明了吉林市地下水来源以现代当地大气降水为主,仅在市区部分江段500 m范围之内受松花江水影响,并计算了该段江水对地下水的补给比例.为判断当地突发性水污染事件对地下水的影响范围及污染防治提供了依据.     

Tracing stable isotope values from meteoric water to groundwater in the southwestern part of the Chad basin

The southwestern Chad basin is a semi-arid region with annual rainfall that is generally less than 500 mm and over 2,000 mm of evapotranspiration. Surface water in rivers is seasonal, and therefore groundwater is the perennial source of water supply for domestic and other purposes. Stable isotope has been measured for rainwater, surface water and groundwater samples in this region. The stable isotope data have been used to understand the inter-relationships between the rainwater, surface water, shallow and deep groundwater of this region. This is being used in a qualitative sense to demonstrate present day recharge to the groundwater. Stable isotope in rainwater for the region has an average value of –4‰ δ¹⁸O and –20‰ δ²H. Surface water samples from rivers and Lake Chad fall on the evaporation line of this average value. The Upper Zone aquifer water samples show stable isotope signal with a wide range of values indicating the complex character of the aquifer Zone with three distinguishable units. The wide range of values is attributable to waters from individual unit and/or mixture of waters of different units. The Middle and Lower aquifers Zones’ waters show similar stable isotopes values, probably indicating similarity in timing and/or mechanism of recharge. These are palaeowaters probably recharged under a climate that is different from today. The Upper Zone aquifer is presently being recharged as some of its waters show stable isotope compositions similar to those of average rainfall waters of the region.     

在某污染的工业废物填埋场环境水文 地质评价中的同位素水文学研究

本文论述了某污染的工业废物填埋场场址的地质、水文地质条件,应用水化学方法、环境同位素技术(地下水中氚及氢、氧稳定同位素)和同位素单孔示踪技术等同位素水文学领域中的新方法对区内地下水的活动条件以及填埋场场址区分布的第四系孔隙潜水和第三纪红层孔隙-裂隙水的成因进行了分析,测量并确定了填埋场下部地下水的流速及流向。研究结果表明场区地下水的运动与地表水无直接水力联系。污染的工业废物填埋后不会通过地下水的迁移造成对地表水的污染,进而证实填埋场的地质、水文地质条件对处置污染的工业废物是安全可靠的。     

招远金矿区水体中硫同位素特征及其对污染来源的指示

稳定同位素因其指纹效应已成为分析矿区污染来源的重要技术手段。文章以招远金矿区为例,应用硫同位素联合水化学分析、聚类分析及氢氧同位素分析招远金矿区水污染特征和成因。通过分析可知,矿区内地表水和地下水主要接受大气降水补给,水力联系密切。水化学类型以SO₄—Ca和SO₄—Na型为主,阴离子以SO₄2-为主,地表水和地下水的NO₃-和Cl-在空间上变异性较大。地表水硫酸盐含量普遍偏高,硫酸盐污染较为严重,高值区出现在玲珑金矿、金翅岭金矿和张星镇附近;而地下水高值区都出现在玲珑金矿附近,且SO₄2-浓度沿着径流方向逐渐降低。地表水中硫酸盐δ34S值介于1.8‰~9.8‰,地下水中硫酸盐δ34S值介于2.7‰~9.6‰,地表水和地下水硫酸盐含量受玲珑金矿硫化、玲珑花岗岩和胶东岩群影响明显。在地下水径流途中,有地表水入渗污染地下水的现象。另外,工业废水的排放也是硫酸盐含量升高的主要原因。研究表明:硫同位素在金矿区硫酸盐污染的来源和特征方面有很好的指示作用,是评价矿山开采对地下水污染的有效工具。     

Groundwater regimes and isotopic studies,Ranger mine area,Northern Territory

Three types of groundwater occur in the area of the Ranger mine. Type A groundwater occurs in the loose sands and gravels occupying the present day stream channels, Type B in the weathering profile and Type C occurs in relatively fresh fractured bedrock occupying open fractures and other cavities. The three types of groundwater can be distinguished both chemically and isotopically. Light stable isotope data suggest that most early rains are lost by evapotranspiration and have no imprint on the groundwater. Later in the wet season, the ground is saturated and groundwater recharge occurs on a regional scale. This younger groundwater sits on the older waters. Mixing is probably minimal as before any large scale mixing could occur, most younger waters are lost by evapotranspiration. Stable isotope data suggest that Type B groundwater in certain areas has some connection with evaporated surface water bodies. Stable isotope measurements for the pollution monitoring bores around the tailings dam do not indicate any connection with the polluted pond waters at the time of sample collection.     

Hydrochemical and stable isotopic investigation of groundwater quality and its sustainability for irrigation in the Hammamet-Nabeul basin,northeastern Tunisia

The major ion hydrochemistry, sodium absorption ratio (SAR), sodium percentage, and isotopic signatures of Hammamet-Nabeul groundwaters were used to identify the processes that control the mineralization, irrigation suitability, and origin of different water bodies. This investigation highlights that groundwater mineralization is mainly influenced by water-rock interaction and pollution by the return flow of irrigation water. The comparison of groundwater quality with irrigation suitability standards proves that most parts of groundwater are unacceptable for irrigation and this long-term practice may result in a significant increase of the salinity and alkalinity in the soils. Based on isotopic signatures, the shallow aquifer groundwater samples were classified into (i) waters with depleted δ¹⁸O and δ²H contents, highlighting recharge by modern precipitation, and (ii) waters with enriched stable isotope contents, reflecting the significance of recharge by contaminated water derived from the return flow of evaporated irrigation waters. The deep-aquifer groundwater samples were also classified into (i) waters with relatively enriched isotope contents derived from modern recharge and mixed with shallow-aquifer groundwater and (ii) waters with depleted stable isotope contents reflecting a paleoclimatic origin. Tritium data permit to identify three origins of recharge, i.e., contemporaneous, post-nuclear, and pre-nuclear. Carbon-14 activities demonstrate the existence of old paleoclimatic recharge related to the Holocene and Late Pleistocene humid periods.     

Hydrological and hydrogeological characterization of groundwater and river water in the North Hanoi industrial area,Vietnam

Degradation of groundwater quality by human activities is a widespread environmental problem in Vietnam. Groundwater there is a major source of water for domestic and industrial purposes. This paper reviews, compiles, and comprehensively analyzes spatiotemporal variations of hydrological and hydrogeological characteristics of shallow and deep groundwater aquifers in northern Hanoi industrial zones and in nearby Red River water. Groundwater level, electrical conductivity, and water temperature were measured in six monitoring wells, complemented by anion, cation, and stable isotope analyses of ground and surface water. The results show that the groundwater in both shallow and deep aquifers was fresh, but mainly calcium-bicarbonate type contaminants and human activities affect groundwater and surface water composition. With the goal of devising sustainable water use regulations, more research must be directed toward long-term monitoring of groundwater and surface water quality, as well as toward detailed investigation of the hydraulic characteristics of local aquifers in the study area.     

地下水水质评价与水资源管理：水文地球化学与同位素方法的应用研究进展

地下水系统是包含地质环境、地下水动力、地下水化学等子集的综合系统,早在2000年前的古罗马时代,人们就已应用水文地球化学方法开展地下水的水化学特征、地下水补给、径流与排泄等研究。近现代同位素技术的发展,为开展地下水补给和可更新性、追踪地下水污染等方面的研究,提供了极大帮助。研究者通过分析地下水样品的水文地球化学指标,如K~+、Ca~(2+)、Na~+、Mg~(2+)等离子,结合δ18 O、δD、δ37 Cl、δ81 Br等稳定同位素指标,在地下水径流特征分析、水岩相互作用过程、地下水咸化、地下水资源管理以及地下水水质问题等研究方面取得了大量成果。本文概述了国内外近年来应用水文地球化学与同位素结合的手段进行地下水系统研究取得的成果及进展,着重回顾了在地下水咸化、地下水硝酸盐及微量有机污染以及地下水资源管理研究中的应用成果。文末讨论了应用水文地球化学与同位素结合的手段研究地下水系统的基本方法,探讨了开展地下水质质量评价与地下水资源管理的科学方法,展望了水文地球化学与同位素方法在地下水有机污染调查研究中的应用前景,认为该方法可以为地下水中新型及持久性有机污染物的来源及污染特征研究提供重要支撑。