共查询到19条相似文献，搜索用时 171 毫秒
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地下水污染问题日益严重,研究溶质运移的弥散理论开始应用于实际问题。建立地下水溶质运移模型,对地下水中污染物的运移及发展趋势进行准确预测,是对地下水进行保护、对地下水污染进行控制的基础。而弥散参数的确定则是地下水溶质运移模型建立的关键环节之一,直接影响着模型预测结果的精度和准确性。 对西宁市贵德县地下水污染的水质运移规律进行分析,在贵德县河滨公园林场采用径向收敛流水动力弥散理论方法进行了第四系含水层现场弥散试验,计算了试验场地潜水含水层的弥散度,获得纵向弥散度(aL)为0.843~0.998 cm,横向弥散度(aT)经验推断值为0.17~0.20 cm,为进一步建立该地区的地下水溶质运移模型、预测地下水污染的发展趋势和评价该地区地下水环境质量提供了数据参考。 相似文献
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垃圾堆放场对地质环境影响的模拟分析 总被引：6，自引：0，他引：6
在综合国内外文献的基础上,通过现场实地调查和室内物理模拟试验、渗滤试验、污染物化学动力学转化试验,概化建立了上海老港垃圾堆放场以有机氮、ＮＨ＋４、ＮＯ－２、ＮＯ－３４种离子为污染质的非饱和土层－潜水含水层水动力弥散联合数学模型,应用所建联合数学模型对上海老港大型垃圾堆放场的地质、水文地质条件、垃圾浸沥液发生量、污染质的运移和转化进行了模拟计算和预测分析。预测了垃圾堆放期１０年和封场后２０年内污染质在非饱和土层－潜水含水层中迁移、转化的规律和排污去向,并得出如果保持目前垃圾堆放状态,其污染范围每年将向内陆含水层扩展９０～１００ｍ的预测结果。这些预测分析为上海浦东新区垃圾堆放场的环境保护提供了科学依据。 相似文献
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目前对潜水含水层地下水潮汐效应和水文地质参数求解方法的研究相对较少.通过对福建古雷半岛滨海潜水含水层地下水潮汐效应和海水潮汐动态的观测, 运用Fourier频谱分析方法确定了研究区海水潮汐波动方程(波动特征参数), 并以此作为地下水的边界条件, 推导了潜水含水层地下水潮汐效应的波动方程, 利用最小二乘法以地下水水位波动观测值为目标函数对潜水含水层的渗透系数与重力给水度的比值进行了反演识别, 为类似地区水文地质参数的确定提供了借鉴, 也为该区后续地下水中溶质迁移规律的研究奠定了基础. 相似文献
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赵勇胜 《吉林大学学报(地球科学版)》1992,(2)
弥散理论是污染质在含水层中运移模型的基本理论.但在实际应用中存在着不少问题和争议.本文对污染质在含水层中运移的弥散作用进行了分析探讨.并应用MOC水质模型对弥散参数的作用进行了分析,证明了在一般情况下,污染质在含水层中的运移主要受对流作用控制,弥散参数的变化对水质模型结果的影响相对较小.在特定的水文地质条件下,弥散作用对污染质的运移是重要的. 相似文献
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以某污染厂区为研究对象,通过野外调查并结合已有资料,利用GMS软件建立研究区域地下水流场模型和溶质运移模型,并且详细分析了地下水污染规律。研究结果表明:降雨入渗扩散方式下,污染物在地下水中的迁移速率与污染物的浓度及地下水介质密切相关。在潜水含水层中,污染物主要以垂向运移为主,并且受污染源强影响较大,污染物浓度越高,其垂向运移速率越快,污染物在水平面上的扩散速率受污染源强的影响较小;在承压含水层中,污染物沿水流方向迁移,并且呈现匀速扩散趋势。 相似文献
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泉水作为济南市的城市名片,具有重要的经济和社会价值,把握泉域内突发污染质泄漏对其产生的影响至关重要。本文概化建立了济南市的水文地质概念模型,利用地下水非稳定流数值模型对济南市区泉群附近范围的地下水进行了分析研究,得到了济南市区泉域内地下水的时空分布规律及污染物运移特性。在此基础上,分析某新建项目污染质泄漏对地下水环境产生的影响,通过设置不同的横纵向弥散度对污染物运移特性进行探究。结果表明,在泉群附近区域内,污染物纵向运移过程中对流起主要作用,纵向弥散度的取值影响较小; 而污染物横向运移过程中弥散起主要作用,横向弥散度的取值影响较大。本研究成果对泉群附近的地下水环境保护及地下水污染防控具有重要借鉴意义。 相似文献
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Liu Changli Zhang Feng-E Zhang Yun Song Shuhong Zhang Sheng Ye Hao Hou Hongbing Yang Lijuan Zhang Ming 《Environmental Geology》2005,48(8):1107-1115
The water quality of shallow aquifers that have direct relationship to human heath and ecological safety has been seriously
threatened by widespread dumping of industrial solid waste, urban and rural garbage. A garbage dump field with hydrogeological,
environ-geological characteristics typical of the Beijing plain was selected for investigation. A hydrogeological model was
constructed and the equations used to describe pollutant transport in one-dimensional (1D) steady, uniform groundwater flow
to investigate the transport/diffusion processes. In addition to the coefficients for calculation, diffusion coefficient and
other coefficients of the aquifer were obtained by conducting in situ diffusion experiments and sample tests. Velocity and
scope of pollutant transport/diffusion process were calculated. Accordingly, the real pollution situation in the aquifer was
evaluated through in situ drilling and sample testing. Transport/diffusion processes of pollutants within the aquifer abide
by the solute equation applicable to 1D steady flow. The transport and diffusion dominate in the direction of groundwater
flowing at a speed of about 120 m per year. Comparably, the lateral diffusive width is much smaller. Pollution degree decreases
by the law of Y=1.08 exp(33.533/X), where Y is the distance from the garbage dump field and X is the overall pollution index. 相似文献
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Groundwater aquifer vulnerability has been assessed by incorporating the major geological and hydrogeological factors that affect and control the groundwater contamination using GIS-based DRASTIC model along with solute transport modeling. This work demonstrates the potential of GIS to derive a vulnerability map by overlying various spatially referenced digital data layers (i.e., depth to water, net recharge, aquifer media, soil media, topography, the impact of vadose zone and hydraulic conductivity) that portrays cumulative aquifer sensitivity ratings in Kishangarh, Rajasthan. It provides a relative indication of groundwater aquifer vulnerability to contamination. The soil moisture flow and solute transport regimes of the vadose zone associated with specific hydrogeological conditions play a crucial role in pollution risk assessment of the underlying groundwater resources. An effort has been made to map the vulnerability of shallow groundwater to surface pollutants of thestudy area, using soil moisture flow and contaminant transport modeling. The classical advection-dispersion equation coupled with Richard’s equation is numerically simulated at different point locations for assessing the intrinsic vulnerability of the valley. The role of soil type, slope, and the land-use cover is considered for estimating the transient flux at the top boundary from daily precipitation and evapotranspiration data of the study area. The time required by the solute peak to travel from the surface to the groundwater table at the bottom of the soil profile is considered as an indicator of avulnerability index. Results show a high vulnerability in the southern region, whereas low vulnerability is observed in the northeast and northern parts. The results have recognized four aquifer vulnerability zones based on DRASTIC vulnerability index (DVI), which ranged from 45 to 178. It has been deduced that approximately 18, 25, 34, and 23% of the area lies in negligible, low, medium and high vulnerability zones, respectively. The study may assist in decision making related to theplanning of industrial locations and the sustainable water resources development of the selected semi-arid area. 相似文献
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悦康药业在开发和生产过程中可能会对区域地下水环境造成影响。基于研究区水文地质条件,建立水文地质概念模型,分别对拟开采的第Ⅲ承压含水层,运用水流运动方程对项目开采15年后的地下水位进行模拟预测;运用溶质运移数学模型对药厂建成后污水处理站对潜水和第Ⅰ承压水进行污染物模拟预测。水位模拟结果表明,15年后含水层(组)中形成降落漏斗大于1 m的范围为0. 45 km~2,形成地面沉降的可能性较小。污染物模拟预测选取COD_(Mn)、氨氮作为预测因子,分别预测污染发生100天、720天及1 800天后污染物迁移情况。污染物模拟结果表明污水站溶质扩散范围较小,5年后COD_(Mn)最大迁移距离为40 m,中心体积质量降为5. 0 mg/L;氨氮最大迁移距离为35 m,中心体积质量降为0. 3 mg/L,对区域地下水水质影响不大。 相似文献
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通过对焦作地区浅层地下水中铬(Ⅵ)污染物分布特征进行调查,分析了研究区浅层地下水中铬(Ⅵ)的污染机理,并运用Visual MODFLOW建立地下水流模型及溶质运移模型,模拟预测了浅层地下水中铬(Ⅵ)的迁移规律。结果表明:研究区浅层地下水铬(Ⅵ)污染严重,污染源是位于老君庙西南方向的焦作某电厂堆灰场,主要原因是露天堆放的粉煤灰中的铬(Ⅵ)污染物在长期淋滤作用下下渗污染含水层。气候条件、包气带岩性、地下水化学环境以及人为因素等也间接使浅层地下水铬(Ⅵ)浓度升高;模拟结果显示在未来的五年时间内,受地形和地下水动力场的影响,浅层地下水中铬(Ⅵ)的迁移方向与地下径流方向一致,沿大沙河水流方向上扩散速度更快,污染区域面积逐渐增大。 相似文献
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The fluoride contained in the filter liquor produced by fly ash in the thermal power plant which takes the coal as fuel can lead to groundwater pollution. Therefore, it is of great significance to study the migration characteristics of the pollutants in groundwater, in order to control and prevent the groundwater fluoride pollution. By adopting the numerical modeling method, this paper takes the ash-storage yard of Shahe Power Plant in Xingtai City as an example, to study the characteristics of fluoride migration in phreatic water, and establish a two-dimensional groundwater flow and water quality model on the basis of the hydrogeological condition analysis in this study area. Meanwhile, based on the Vmodflow software, the migration regulation of the fluoride in groundwater has been simulated. Because the phreatic aquifer of this area belonging to the Shahe alluvial-diluvial sediments and with a coarse lithology as well as high permeability, the migration and diffusion ability of the fluoride in this area is relatively strong. It turns out that the longest migration distance in 5 years is 892 m and that within 8 years is 1 515 m. 相似文献
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以云南某矿区为研究对象,在详细调查区域水文地质条件和已有资料的基础上,结合调查区监测井,利用GMS软件建立研究区域地下水水流场模型和溶质运移模型。模型计算了在合理误差范围内的水流场模型并预测了硫酸盐在持续泄漏730d、180d后切断泄漏源,硫酸盐的迁移过程。研究结果表明:随着持续泄漏时间的增加,调查区域北部边界附近受到污染的浓度越高、污染范围越广,超标的污染物在北部边界区域进入岩溶含水层,遇到岩溶带会加速污染物向下游运移,破坏下游水质、危及下游村庄饮用水安全。 相似文献
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Groundwater pollution due to discharge of industrial effluents in Venkatapuram area, Visakhapatnam, Andhra Pradesh, India 总被引：1，自引：0，他引：1
Hindustan Polymers Limited was established in the Venkatapuram area in the northwestern part of Visakhapatnam urban agglomeration.
Untreated industrial effluent from the plant is discharged with total dissolved solids concentrations reaching up to 6500 mg/l.
The groundwater pollution was identified as early as 1981 and a hydrogeologic and water-quality database is available from
1981. The groundwater quality in the plant environs is found to be in the range of 3500–4500 mg/l. Major chemical constituents
of industrial-waste waters consist of Na, Cl, and SO4. Some characteristic parameters of the aquifer were estimated. The available hydrogeologic and hydrologic data was analyzed
to conceptualize the groundwater regime. A mathematical groundwater flow model was constructed to compute the hydraulic head
at the center of finite-difference grid. The computed head distribution and effective porosity of the formations were used
to calculate the groundwater flow velocity. The computed velocity field was ultimately used to prognose the pollutant migration
in groundwater accounting for the advection and dispersion processes in the mass transport model and for determining the time-dependent
pathlines of pollutant. Areal migration of pollutants from the source was predicted up to year 2002.
Received: 23 December 1996 · Accepted: 9 September 1997 相似文献
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Tracer concentration data from field experiments conducted in several carbonate aquifers (Malaga province, southern Spain) were analyzed following a dual approach based on the graphical evaluation method (GEM) and solute transport modeling to decipher flow mechanisms in karst systems at regional scale. The results show that conduit system geometry and flow conditions are the principal factors influencing tracer migration through the examined karst flow routes. Solute transport is mainly controlled by longitudinal advection and dispersion throughout the conduit length, but also by flow partitioning between mobile and immobile fluid phases, while the matrix diffusion process appears to be less relevant. The simulation of tracer breakthrough curves (BTCs) suggests that diffuse and concentrated flow through the unsaturated zone can have equivalent transport properties under extreme recharge, with high flow velocities and efficient mixing due to the high hydraulic gradients generated. Tracer mobilization within the saturated zone under low flow conditions mainly depends on the hydrodynamics (rather than on the karst conduit development), which promote a lower longitudinal advection and retardation in the tracer migration, resulting in a marked tailing effect of BTCs. The analytical advection-dispersion equation better approximates the effective flow velocity and longitudinal dispersion estimations provided by the GEM, while the non-equilibrium transport model achieves a better adjustment of most asymmetric and long-tailed BTCs. The assessment of karst underground flow properties from tracing tests at regional scale can aid design of groundwater management and protection strategies, particularly in large hydrogeological systems (i.e. transboundary carbonate aquifers) and/or in poorly investigated ones. 相似文献
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弱透水层是含水层系统的重要组成部分,其水文地质参数的准确获取一直以来都是研究难点,传统室内试验难以克服应力状态及环境变化对土层参数的影响,因此如何在原位状态下评价其水文地质参数有着重要意义。选取呼和浩特盆地某淤泥层为研究对象,基于抽水试验和溶质运移试验获得的多源数据,采用基于控制体积有限差分法的非结构化网格（Unstructured Grid）方法,建立三维地下水流-溶质运移耦合模型,对弱透水层水文地质参数进行反演。结果显示:模型计算的抽水井中水位和溶质浓度变化规律与实际观测数据能够较好拟合,模型识别出的抽水含水层渗透参数（4.8 m/d）与通过解析法计算得出的结果（4.17 m/d）相近,建立的数值模型符合实际水文地质条件;反演得到淤泥质弱透水层垂向渗透系数为1.2×10?4 m/d、储水率为1.0×10?5 m?1。基于多源数据的参数反演方法可为弱透水层参数研究提供借鉴。 相似文献