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构建合理的水文地质概念模型对于地下水数值模拟至关重要,概念模型如果确定不合理,整个数值模拟将毫无意义。通常水文地质调查可以大致确定水文地质概念模型,然而对于一些不易被发现的补给源,通过水文地质调查也无法确定。水化学和同位素特征对地下水的补给源及水流路径有很好的指示作用,可以根据这些信息对水文地质概念模型进行细化。文章通过对研究区地下水取样,分析地下水水化学和同位素特征,确定出研究区内不易识别的地下水补给源及顶层黏土-粉质黏土的透水性,最终细化了水文地质概念模型边界条件。这对于后期得到正确的地下水流和溶质运移模拟结果具有重要意义。 相似文献
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通过勘探发现了滕南矿区侏罗系砾岩含有丰富的地下水资源可以利用。该区侏罗系砾岩含水层具有厚度大、分布面积广的整体特征;其含水性在平面上的严重不均一性与构造、含水层埋深和第四系水文地质条件有关;侏罗系地下水动态类型属人为－气象型;地下水化学万分与含水介质、水动力条件及原始沉积环境等因素关系密切;地下水补、径、排 条件受构造、第四系水文地质条件、地表水体的分布及矿井开采等因数影响较大。 相似文献
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介绍了满洲里市的自然地理特征。通过大量的水文地质调查、地面物探、工程测量、水文钻探、抽水试验、室内测试分析等方法和手段,确定了满洲里市的地层、构造、地下水水文地质特征,即透水层、隔水层、单位出水量、导水系数、单井出水量、影响半径和水质类型。最后提出开采建议。 相似文献
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圆明园遗址公园水文地质条件分析 总被引：2，自引：0，他引：2
通过遥感解译、水文地质调查、钻孔和抽水试验,结合区域水文、气象和地质等资料,对圆明园的水文地质条件有了初步认识:圆明园处在清河古河道范围内,浅层地下水可分为潜水和第一层承压水,含水层岩性以砂类为主,与湖水有直接联系的潜水含水层的渗透系数大于20md;20世纪50～60年代,圆明园所在区域地下水位较高,地下水补给湖水;近年来,受降水减少和地下水开采等因素影响,地下水位下降较大,湖水位高于潜水位,自然条件下湖水补给地下水。 相似文献
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在对宜昌磷矿区域水文单元研究的基础上,通过水文地质调查、钻探、抽水试验及钻孔与坑道地下水动态观测等技术方法手段,查明了区域边界与杨柳矿区水文地质条件及矿坑充水因素;确定矿区水文地质条件中等. 相似文献
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大型抽水试验的水文地质意义 总被引：2，自引：0，他引：2
本文以山东省东阿县下马头水源地为实例,探讨了大型抽水试验的主要水文地质意义,包括:确定地下水的主要补给来源及方向,抽水影响范围及程度,水源地岩溶含水层的富水性及供水保证能力,水源地附近地下水与地表水之间的水力联系,水源地附近主要断裂构造的水力性质,水源地抽水对下游水源地的影响以及水文地质参数与水源地地下水允许开采量计算。 相似文献
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《地下水》2017,(3)
河南省西部三门峡—洛阳(主要为陕县、渑池、新安三县)之间,面积约3 000 km2,是河南省最重要的铝土矿资源产地。通过对区域地质构造、矿产分布概况论述,对区域水文地质条件,包括区域水文地质分区、区域地下水系统、区域构造水文地质特征、区域含水层、区域地下水补径排条件进行分析,结果显示,豫西区域地下水主要为寒武-奥陶系灰岩岩溶裂隙水,受地形、构造等因素作用影响,富水性不均,一般富水性中等偏弱,局部强富水,是区域铝土矿开采最主要充水因素,也是豫西地区主要生活用水,若铝土矿开采过多,不仅会造成区域地下水水位持续下降,还会严重污染区域地下水的水质,特别是铝土矿底板奥灰水,其在大部分地区具有承压性,铝土矿开采直接破坏了其隔水顶板,因此其对地下水的破坏是不可逆的,也是无法补救的;因此,在未来铝土矿的开采过程中,特别是下部奥灰水承压地段,一定要评估其开采对地下水造成的危害程度,权衡利弊,做到科学合理开采。 相似文献
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Venkatesh Uddameri Vivekanand Honnungar E. Annette Hernandez 《Environmental Earth Sciences》2014,71(6):2653-2671
Principal component analysis has been applied for source identification and to assess factors affecting concentration variations. In particular, this study utilizes principal component analysis (PCA) to understand groundwater geochemical characteristics in the central and southern portions of the Gulf Coast aquifer in Texas. PCA, along with exploratory data analysis and correlation analysis is applied to a spatially extensive multivariate dataset in an exploratory mode to conceptualize the geochemical evolution of groundwater. A general trend was observed in all formations of the target aquifers with over 75 % of the observed variance explained by the first four factors identified by the PCA. The first factor consisted of older water subjected to weathering reactions and was named the ionic strength index. The second factor, named the alkalinity index explained greater variance in the younger formations rather than in the older formations. The third group represented younger waters entering the aquifers from the land surface and was labeled the recharge index. The fourth group which varied between aquifers was either the hardness index or the acidity index depending on whether it represented the influences of carbonate minerals or parameters affecting the dissolution of fluoride minerals, respectively. The PCA approach was also extended to the well scale to determine and identify the geographic influences on geochemical evolution. It was found that wells located in outcrop areas and near rivers and streams had a larger influence on the factors suggesting the importance of surface water–groundwater interactions. 相似文献
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A three dimensional steady-state finite difference groundwater flow model is used to quantify the groundwater fluxes and analyze
the subsurface hydrodynamics in the Akaki catchment by giving particular emphasis to the well field that supplies water to
the city of Addis Ababa. The area is characterized by Tertiary volcanics covered with thick residual and alluvial soils. The
model is calibrated using head observations from 131 wells. The simulation is made in a two layer unconfined aquifer with
spatially variable recharge and hydraulic conductivities under well-defined boundary conditions. The calibrated model is used
to forecast groundwater flow pattern, the interaction of groundwater and surface water, and the effect of pumping on the well
field under different scenarios. The result indicates that the groundwater flows regionally to the south converging to the
major well field. Reservoirs and rivers play an important role in recharging the aquifer. Simulations made under different
pumping rate indicate that an increase in pumping rate results in substantial regional groundwater level decline, which will
lead to the drying of springs and shallow hand dug wells. Also, it has implications of reversal of flow from contaminated
rivers into productive aquifers close to main river courses. The scenario analysis shows that the groundwater potential is
not enough to sustain the ever-growing water demand of the city of Addis Ababa. The sensitivity and scenario analysis provided
important information on the data gaps and the specific sites to be selected for monitoring, and may be of great help for
transient model development. This study has laid the foundation for developing detailed predictive groundwater model, which
can be readily used for groundwater management practices. 相似文献
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Many environmental problems are rooted in human behavior. This study aimed to explore the causal effect of cultural environmental bias on ‘sustainable behavior’ among agricultural groundwater users in Fars province, Iran, according to Klockner’s comprehensive model. A survey-based research project was conducted to gathering data on the paradigm of environmental psychology. The sample included agricultural groundwater users (n = 296) who were selected at random within a structured sampling regime involving study areas that represent three (higher, medium and lower) bounds of the agricultural-groundwater-vulnerability spectrum. Results showed that the “environment as ductile (EnAD)” variable was a strong determinant of sustainable behavior as it related to groundwater use, and that EnAE had the highest causal effect on the behavior of agricultural groundwater users. The adjusted model explained 41% variance of “groundwater sustainable behavior”. Based on the results, the groundwater sustainable behaviors of agricultural groundwater users were found to be affected by personal and subjective norm variables and that they are influenced by casual effects of the “environment as ductile (EnAD)” variable. The conclusions reflect the Fars agricultural groundwater users’ attitude or worldview on groundwater as an unrecoverable resource; thus, it is necessary that scientific disciplines like hydrogeology and psycho-sociology be considered together in a comprehensive approach for every groundwater study. 相似文献
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《Applied Geochemistry》2005,20(1):157-168
In monitoring a minor geochemical element in groundwater or soils, a background population of values below the instrumental detection limit is frequently present. When those values are found in the monitoring process, they are assigned to the detection limit which, in some cases, generates a probability mass in the probability density function of the variable at that value (the minimum value that can be detected). Such background values could distort both the estimation of the variable at nonsampled locations and the inference of the spatial structure of variability of the variable. Two important problems are the delineation of areas where the variable is above the detection limit and the estimation of the magnitude of the variables inside those areas. The importance of these issues in geochemical prospecting or in environmental sciences, in general related with contamination and environmental monitoring, is obvious. In this paper the authors describe the two-step procedure of indicator kriging and ordinary kriging and compare it with empirical maximum likelihood kriging. The first approach consists of using a binary indicator variable for estimating the probability of a location being above the detection limit, plus ordinary kriging conditional to the location being above the detection limit. An estimation variance, however, is not available for that estimator. Empirical maximum likelihood kriging, which was designed to deal with skew distributions, can also deal with an atom at the origin of the distribution. The method uses a Bayesian approach to kriging and gives intermittency in the form of a probability map, its estimates providing a realistic assessment of their estimation variance. The pros and cons of each method are discussed and illustrated using a large dataset of As concentration in groundwater. The results of the two methods are compared by cross-validation. 相似文献
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Hydrological interactions between surface water and groundwater (GW) can be described using hydrochemical and biological methods. Surface water–groundwater interactions and their effects on groundwater invertebrate communities were studied in the Nakdong River floodplain in South Korea. Furthermore, the GW-Fauna-Index, a promising new index for assessing the strength of surface-water influence on groundwater, was tested. The influence of surface water on groundwater decreased with increasing depth and distance from the river. While hydrochemistry prevailingly reflected the origin of the waters in the study area (i.e. whether alluvial or from adjacent rock), faunal communities seemed to display an affinity to surface-water intrusion. Fauna reacted quickly to changes in hydrology, and temporal changes in faunal community structure were significantly linked to the hydrological situation in the floodplain. The metazoan faunal community and the GW-Fauna-Index allow a distinction between surface and subsurface waters with varying degrees of exchange. The results indicate that hydrological conditions are reflected by faunal assemblages on a high spatiotemporal resolution, and that surface-water intrusion can be estimated using the GW-Fauna-Index. 相似文献
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区域尺度上含水层非均质具有复杂的结构性和随机性,难以准确刻画,造成非均质对区域地下水流系统的影响机制研究不够深入。本文以鄂尔多斯盆地白垩系地下水流系统为研究实例,选择典型剖面,采用剖面二维随机数值模拟方法,通过对比不同非均质刻画方法下地下水流场的变化,探讨含水层层状非均质对地下水流系统的影响机制。结果显示,均质条件下模型各向异性（含水层水平和垂向渗透系数比值Kh/Kv）取值为1000时,地下水流场与实际条件较为接近;非均质条件下,渗透系数方差取值0.91,水平相关长度取值5000 m,Kh/Kv取值150时,接近实际条件。研究表明,在大尺度地下水流模拟研究中,采用水平相关长度、渗透系数方差和各向异性值三个变量生成的随机场能很好地刻画含水层的层状非均质特征及其对水流系统的影响控制作用。由于含水层不同尺度层状非均质的叠加效应,采用均质各向异性介质等效概化含水层层状非均质性会造成等效各向异性值偏大失真的效应。 相似文献
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Brankica Majkić-Dursun Ivana Oros Đulija Boreli-Zdravković 《Environmental Earth Sciences》2018,77(1):30
The reported study includes analysis of 14 physico-chemical parameters of alluvial groundwater based on data collected from 26 piezometers in the Velika Morava River Basin from 2004 to 2014. Eleven of the parameters were assessed applying hierarchical cluster analysis and principal component analysis to examine the spatial distribution, identify the main processes in groundwater variations and segregate the dominant sampling sites based on the characteristic parameters. A Piper diagram shows that the studied alluvial groundwaters are predominantly of the Ca2+–HCO3? type (67.3%) and to a lesser extent of the mixed Ca2+–Mg2+–HCO3? type (21.6%). Hierarchical clustering results in four clusters depending on the similarities of the hydrochemical parameters. Principal component analysis explains 65.4% of total variance with PC1 (32.5% variance), PC2 (19.8% variance) and PC3 (13.1% variance). A comparative analysis reveals that the main processes responsible for the hydrochemical composition of groundwater in the Velika Morava alluvion are carbonate dissolution-anthropogenic pressure, feldspar weathering and migration caused by river–aquifer interaction. Considerable loading of the alluvial groundwater caused by a complex geologic framework, natural factors and human activities in the river basin contributed to the segregation of six dominant sampling sites. The obtained results can be very useful in the development of an optimal spatial plan for groundwater monitoring, focusing on increasing the density of the national monitoring network and frequency of assessing alluvial groundwater on the dominant sampling sites (from annual to seasonal). 相似文献
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M. L. Calvache Ph.D. C. Duque Ph.D. J. M. Gomez Fontalva Ph.D. F. Crespo B.Sc. 《International Journal of Environmental Science and Technology》2011,8(2):223-236
The temperature depth profiles of six wells in the Motril-Salobren～a aquifer were used as a basis for a comparative analysis involving various parameters to determine their relations and factors influencing the different trends. There is a clear influence of ambient temperature on all the profiles, with a lag time of two to five months. Nevertheless, there are clear differences in the temperature depth profile patterns that can be accounted for by other factors. First, there is a greater influence of localized recharge; Guadalfeo River as opposed to diffuse recharge; irrigation return flow and rainfall. Three of the wells located near the riverbed of the Guadalfeo River have extremely variable temperature-depth profiles and show clear river influence. In springtime, during the highest flood stages of the river due to cold melt water from the Sierra Nevada, the groundwater falls in temperature. During secondary peaks in river flow rates during the autumn due to rainfall, the warm water increases groundwater temperature. The effect of the river recharge decreases with distance from the course since there is less mixing with water from the Guadalfeo River. In addition, there are two temperature-depth profiles in which temperature variations remain shallow and follow a pattern that cannot be attributed to the influence of either of the above two parameters. Among these two cases, the most influential factor is the groundwater flow pattern typical of a discharge zone, characterized by vertical-flow components. 相似文献
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近年来,在人类活动强烈的干扰下,湿地地下水环境日益恶化。传统的地下水质量评价方法因未区分天然高背景和人为污染的影响,评价结果不能全面、真实、可靠地表示出水质的实际状态。笔者等选取地下水主要超标指标进行因子分析,并根据各因子的得分和方差贡献率计算各采样点得分,并最终计算因子影响下的综合得分。综合评价结果表明,研究区地下水主要有3个影响因子,因子1主要为天然高背景引起的高铁(TFe),锰(Mn)和铝(Al),因子2为农业及生活污水影响导致的NH+4、高锰酸钾指数(CODMn)和NO-2超标,因子3为天然与人为复合影响导致的I-污染。计算得出的综合影响程度与传统的水质评价结果吻合,综合影响程度得分图不仅可以得出地下水质信息,还可根据确定的因子得出天然与人为对地下水质的影响。 相似文献
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近年来,在人类活动强烈的干扰下,湿地地下水环境日益恶化。传统的地下水质量评价方法因未区分天然高背景和人为污染的影响,评价结果不能全面、真实、可靠地表示出水质的实际状态。笔者等选取地下水主要超标指标进行因子分析,并根据各因子的得分和方差贡献率计算各采样点得分,并最终计算因子影响下的综合得分。综合评价结果表明,研究区地下水主要有3个影响因子,因子1主要为天然高背景引起的高铁（TFe）,锰（Mn）和铝（Al）,因子2为农业及生活污水影响导致的NH+4、CODMn和NO-2超标,因子3为天然与人为复合影响导致的I-污染。计算得出的综合影响程度与传统的水质评价结果吻合,综合影响程度得分图不仅可以得出地下水质信息,还可根据确定的因子得出天然与人为对地下水质的影响。 相似文献