基于贝叶斯网络的地下水环境系统决策管理研究

应用贝叶斯网络解决地下水环境管理中具有不确定性的多目标决策问题,通过对决策变量氮肥施用量以及灌溉模式的调控,减少水中的硝酸盐含量,达到既能有效改善水环境又不至使农民经济利益受到损害的目标。通过分析具体的地下水环境管理系统中变量间的相互关系,构建描述变量间不确定性关系的贝叶斯网络模型,其中包括表示其依赖关系的有向无环图和表示其具体概率依赖程度的条件概率表。并在多个水环境管理目标均达到最优的前提下进行概率推理,得到决策变量氮肥施用量以及灌溉模式取不同值时目标变量的概率分布情况。最终确定出能使所有目标均达到最优的合理的水环境管理决策:(1)使用喷灌,将氮肥施用量控制在0.01~0.03 kg/m2;(2)使用漫灌,将氮肥施用量控制在0.01~0.02 kg/m2。     

Role of groundwater protection planning in groundwater governance: A case study from North India

In the present case study, impact of urbanization and industrial development on the shallow groundwater regime of Saharanpur town of Uttar Pradesh in India is examined with the aim of planning groundwater protection for better governance. The hazardous physicochemical and bacteriological parameters and heavy metals detected in the shallow aquifer include harmful pathogens like fecal coliforms, heavy metals like cadmium, chromium, nitrates and sulphates. An assessment of ground water vulnerability using the well known DRASTIC method has confirmed that the shallow groundwater in some central and southern localities of Saharanpur town fall in the medium risk zones. Further, using field data of 32 electrical resistivity soundings, the protective capacity of the unconfined aquifer is assessed in terms of a ‘total longitudinal conductance’ of the semi-pervious to impervious sediments overlying the unconfined aquifer. However, some areas aligned along a northwest-southeast and in the western parts of the town seem to have relatively higher protective capacity against infiltrating waste pollutants. A ground water protection planning map prepared by combining the DRASTIC map and the ‘potentially hazardous pollutants’ map has brought out the need to install eleven new groundwater quality monitoring wells in the town at locations near the line sources and point sources of pollution. This approach can be readily employed by the decision makers in framing sound guidelines for groundwater protection and governance.     

基于数值模型的地下水污染预警方法研究

地下水是中国许多城市主要的供水水源,目前中国部分城市地下水已受到不同程度的污染,导致地下水资源供需矛盾日益突出。进行地下水污染预警是保护地下水资源的一个有效措施,当前国内外相关研究刚刚起步,有关预警理论、方法和技术框架仍未形成一套完善的体系。本文简述了地下水污染预警的研究现状及存在的不足,并以中国北方某铬渣场地为例,根据当地的水文地质条件,利用数学模型建立了地下水污染预警模型,给出了不同等级的地下水污染预警分区,研究结果可为当地地下水污染防治和地下水污染控制规划提供科学依据。     

基于复值曲波变换的地震数据重建方法

传统的地震数据采样必须遵循奈奎斯特采样定理,而野外数据采样可能由于地震道缺失或者勘探成本限制,不一定满足采样定理的要求,因此需要进行叠前数据重建,以满足后续处理的要求。为此,笔者提出一种基于复值曲波变换和凸集投影算法( POCS)的地震数据重建方法。首先引入凸集投影算法和能够刻画地震数据局部化特征的复值曲波变换,在重建过程中针对传统阈值参数收敛速度较慢的缺点,提出了指数平方根衰减规律的阈值参数,并采用硬阈值算子对二维地震数据进行重建,从而降低了迭代次数,提高了重建精度。通过理论数据的研究表明,该方法重建效果显著,最后将该技术应用于实际地震勘探资料,获得较好的应用效果。     

基于小波分析的趵突泉地下水补给范围探讨

为查明济南趵突泉地下水补给范围以及市区、西郊对趵突泉的补给范围所占比例,选取2010—2020年趵突泉泉域20个地下水长期监测点的岩溶水位数据,采用交叉小波变换的方法对地下水位与降水量的时滞进行分析,并结合泉水的功能分区对趵突泉地下水补给范围进行探讨,计算市区、西郊对趵突泉的补给范围所占比例。结果表明：（1）随着地下水径流长度的增加,地下水位对降水时滞呈现增大的趋势,从78.58 d增大至129.22 d,济南西郊的时滞变化梯度大于济南市区;（2）玉符河下游地下水补给范围大,径流路径长,河流沿线地下水位对降水量的时滞大于两侧;刘长山−郎茂山−万灵山一带地下水径流路径较短,岩溶富水性较差,地下水位对降水量的时滞小于两侧;济南市区与西郊地下水存在水力联系;（3）选取趵突泉水位与降水量的时滞等值线为趵突泉补给范围的北边界,东边界为东坞断裂,西边界为马山断裂,南边界为地表分水岭,趵突泉的补给范围为1 390.54 km²。（4）济南西郊对趵突泉的补给范围为1 133.09 km²,市区对趵突泉的补给范围为257.45 km²,西郊和市区对趵突泉的补给范围面积比值为4.4∶1。     

基于沉积物物质来源的地下水化学特征分析:以北京市平原区为例

沉积物物质来源不同,其沉积环境和沉积特征不同,其地球化学特征、水动力体系和地下水循环响应不同。文中以北京市平原区为例,通过沉积物物质来源分析,研究浅层地下水化学分布特征。首先根据地下水系统分区进行取样和实验,采用矿物组合、风化强度及相关分析等多种方法综合分析北京市平原区沉积物的物质来源及其组合特征,多种方法分析结论一致,即北京平原区的主要物质来源:一是流经燕山山地花岗岩变质岩区的潮白河系统,一是流经西山山地石灰岩区的永定河系统;而两系统中、下部是多期物源多层交叠、纵横交错沉积形成的。其次在物源分析基础上通过水质分析研究两系统剖面上地下水水化学特征,即两系统剖面地下水化学类型主要为HCO3--Ca.Mg型水;但永定河系统的溶解性总固体、阴阳离子浓度均大于潮白河系统,这与两剖面所在系统物源分析的结果相吻合,即分析结果表明物源的沉积环境及沉积组合特征决定了系统的地下水化学特征。     

Impact of over-exploitation on groundwater quality: A case study from WR-2 Watershed,India

The WR-2 watershed is located in the Deccan trap basaltic terrain of Maharashtra State, India. The watershed area incorporates a rich orange orchard belt that requires a huge quantity of water for irrigation. This requirement is mostly met through groundwater, extracted from the shallow aquifers of the WR-2 watershed. However, over the years, excess withdrawal of groundwater from these aquifers has resulted in depletion of groundwater level. The declining trends of groundwater level, both long term and short term, have had a negative impact on the groundwater quality of the study area. This effect can be gauged through the rising electrical conductivity (EC) of groundwater in the shallow aquifers (dug wells) of the WR-2 watershed. It is observed that the long term declining trend of groundwater level, during 1977–2010, varied from 0.03 to 0.04 m per year, whereas the corresponding trend of rising EC varied from 1.90 to 2.94 μS/cm per year. During 2007–2010, about 56% dug wells showed a positive correlation between depleting groundwater level and rising EC values. The groundwater level depletion during this period ranged from 0.03 to 0.67 m per year, whereas the corresponding trend of rising EC ranged from 0.52 to 46.91 μS/cm per year. Moreover, the water quality studies reveal that groundwater from more than 50% of the dug wells of the WR-2 watershed is not suitable for drinking purpose. The groundwater, though mostly suitable for irrigation purpose, is corrosive and saturated with respect to mineral equilibrium and shows a tendency towards chemical scale formation.     

地下水应急水源地综合研究——以唐山市平原区为例

为规范地下水应急水源地勘查、评价和研究内容及程序,以唐山市平原区地下水应急水源地为例,运用综合分析和数值模拟法,针对应急水源地的供水特征和生态环境约束,总结了地下水应急水源地的选址原则,探讨了地下水应急水源地研究内容和研究步骤,提出了地下水应急开采量概念。通过研究查明了水文地质条件,确定应急水源地位置; 建立了地下水流模型; 以地质环境为约束,以可持续开发利用为前提条件,评价了应急开采量和地下水资源恢复能力。对唐山市平原区地下水应急水源地的研究表明,该水源地距离现有水源地较远,水文地质条件、补给条件和水质较好,地下水应急水源地的应急开采量约9×104 m3/d,停采后地下水资源恢复能力较好。研究成果对地下水应急水源地的勘查和评价具有指导意义。     

Establishing constraints on groundwater ages with Cl,C, H,and noble gases: A case study in the eastern Paris basin,France

Groundwaters from the Tithonian/Kimmeridgian, Oxfordian and Upper Dogger aquifers, within the eastern part of the Paris basin (France), were characterised using ³H, ¹⁴C and ³⁶Cl, and noble gases tracers, to evaluate their residence times and determine their recharge period. This information is an important prerequisite to evaluating the confinement properties of the Callovo-Oxfordian clay formation sandwiched between the Oxfordian aquifer and the Dogger aquifer, currently being investigated by the French nuclear waste management agency (Andra) for radioactive waste disposal. Data presented in this paper are used to test 4 hypotheses.     

迭代法在现代地下水年龄估算中的应用——以银川平原为例

为克服应用氚同位素方法确定现代地下水年龄过程中存在的,需确定地下水系统输入项的历史背景浓度问题,本文根据地下水同位素数学物理方程,以全混模型为例,利用不同时期地下水同位素的测试结果,通过数学迭代运算,推导出计算现代地下水年龄的计算公式。该方法不仅可以很好地解决地下水系统输入项氚背景浓度恢复时间序列较长的问题,而且对于提高地下水的定年精度具有十分重要的意义。该方法应用到银川平原取得良好的效果,研究表明银川平原浅层地下水的周转时间为30 a。     

Methodology for mapping shallow groundwater quality in urbanized areas: A case study from Lithuania

Cities have a negative impact on the quality of shallow groundwater. Many of Lithuania's urban residents drink water from dug wells. Moreover, polluted shallow groundwater contaminates deeper aquifers of fresh drinking water. Therefore, this situation should be controlled and managed, as far as possible. In order to evaluate the quality of shallow groundwater in an urban area and to create an optimal monitoring system, an original methodology for groundwater mapping has been proposed. It resembles the GIS (geographical information system) technologies. The set of maps, laid one over another, consists of the following: (1) urbanization map, (2) geological-hydrogeological map, (3) groundwater chemistry map, (4) resulting groundwater chemistry factorial analysis map, and (5) pollution and pollutant transport map. The data obtained from studies on dug and geotechnical wells have been used for compilation of the maps. The system for shallow groundwater monitoring in the city with an area of 70 sq km and a population of 140,000 is proposed to consist of about 30 monitoring wells and several dug wells.     

Compositional multivariate statistical analysis of thermal groundwater provenance: A hydrogeochemical case study from Ireland

Thermal groundwater is currently being exploited for district-scale heating in many locations world-wide. The chemical compositions of these thermal waters reflect the provenance and circulation patterns of the groundwater, which are controlled by recharge, rock type and geological structure. Exploring the provenance of these waters using multivariate statistical analysis (MSA) techniques increases our understanding of the hydrothermal circulation systems, and provides a reliable tool for assessing these resources.Hydrochemical data from thermal springs situated in the Carboniferous Dublin Basin in east-central Ireland were explored using MSA, including hierarchical cluster analysis (HCA) and principal component analysis (PCA), to investigate the source aquifers of the thermal groundwaters. To take into account the compositional nature of the hydrochemical data, compositional data analysis (CoDa) techniques were used to process the data prior to the MSA.The results of the MSA were examined alongside detailed time-lapse temperature measurements from several of the springs, and indicate the influence of three important hydrogeological processes on the hydrochemistry of the thermal waters: 1) salinity and increased water-rock interaction; 2) dissolution of carbonates; and 3) dissolution of sulfides, sulfates and oxides associated with mineral deposits. The use of MSA within the CoDa framework identified subtle temporal variations in the hydrochemistry of the thermal springs, which could not be identified with more traditional graphing methods, or with a standard statistical approach. The MSA was successful in distinguishing different geological settings and different annual behaviours within the group of springs. This study demonstrates the usefulness of the application of MSA within the CoDa framework in order to better understand the underlying controlling processes governing the hydrochemistry of a group of thermal springs in a low-enthalpy setting.     

Ground penetrating radar for groundwater exploration in granitic terrains: A case study from Hyderabad

The Ground Penetrating Radar (GPR) is a newly developing geophysical tool for imaging the sub-surface and is potentially useful in groundwater exploration. We test its usefulness in characterizing a groundwater rich lineament near Gajularamaram in the Hyderabad granite terrain, where groundwater is limited to soil, weathering zone and lineaments. The lineament is 2 km long and 50–100 m wide, and oriented in WNW-ESE direction. It is characterized by many closely spaced sub-vertical fractures and faults, majority of which are parallel to the lineament. On either sides of the lineament, sub-horizontal sheet joints are abundant. The lineament is saturated with groundwater that discharge as springs at some places. About 450 m long, 400–100 MHz GPR data (～5–30 m depth) were acquired along five profiles across the lineament. In the lineament, soil thickness varies from ～0.5 m to 5 m, and is underlain by weathered granite. In the WNW part, a thick weathering zone (～15 m) is present and a 10 m wide vertical anomaly zone (lineament) is also present. The presence of shallow reflectors at 1 m depth in the lineament is attributed to the groundwater surface. The GPR images reveal many sub horizontal to gently dipping reflectors, which are interpreted to be the sheet joints. The GPR data clearly reveal the saturated lineament, from which groundwater may migrate laterally to long distance through the sheet joints. We demonstrate the GPR as a rapid geophysical tool that can be used successfully to explore the nearsurface groundwater.     

显生宙烃源岩分布的古板块再造研究

提要：本文依据古地磁方法对不同时期的全球古板块进行再造,并在此基础上叠加了全球大地构造背景、洋流系统、气候带分布以及岩相古地理等要素,共编制了11个时间段古板块格局下的全球烃源岩分布图。综合各种地质要素可以看出烃源岩在时间和空间分布上具有强烈不均匀的特征,在时间上,中、新生代烃源岩无论是从分布范围,还是厚度上,都较古生代更为发育;在空间上,全球显生宙海相烃源岩主要分布于陆棚及斜坡相、台内坳陷等环境,而陆相烃源岩则主要分布在湖盆中心。烃源岩的沉积和保存受到超大陆旋回的控制,超大陆汇聚过程中陆架和适宜陆缘的消失不利于烃源岩的沉积和保存,反之亦然。较高的海平面以及上升流的存在是烃源岩发育的有利条件,全球优质烃源岩富含的有机质泥页岩多发育于海侵体系域顶部与高位体系域底部的密集段中。     

地下水油类污染系统形成机制研究——以某石油化工研究区为例

石油化工是高污染的行业,由于污水的不合理排放以及在生产过程中的跑、冒、滴、漏,大量有毒有害的有机污染物进入地下水系统,造成地下水水质恶化,地下水环境退化,甚至制约着工农业生产的发展,危害人民的身体健康,石油类污染已成为严重的环境问题。本文通过对某石油化工企业地下水油类污染的调查,对地下水石油污染的特征、污染源空间分布规律、地下水石油类污染机理等方面进行了研究。     

Laminated tufa sediments formed from overflow karst springs: Controls on their deposition and carbon–oxygen isotope records

Tufa sediments are freshwater carbonates that precipitate in karst regions after degassing of carbon dioxide from groundwater in contact with the atmosphere. When laminated, these carbonates can provide high‐resolution records for the study of climate, hydrological and environmental conditions at the time of their precipitation. The formation of these carbonates directly depends on the hydrological regime, and in karst regions discontinuous discharges are often recorded. This study investigates the record of recent laminated tufa sediments precipitated downstream overflow springs in Trabaque Canyon (central Spain). The hydrological dynamics of the karst system were monitored for over three years and a stable isotope record was obtained from laminated tufa carbonates precipitated from an overflow spring. Additionally, a hydrological model of overflow springs was generated and a tufa δ¹⁸O record under constrained parameters was simulated. Temperature is the dominant control of the variation in tufa δ¹³C and δ¹⁸O values within each lamina, although when comparing different laminae, δ¹³C_DIC and δ¹⁸O of river water are also major controls. The positive correlation between tufa δ¹³C values and water temperature is caused by the fractionation occurred by carbon dioxide degassing due to the thermal dependence of carbon dioxide solubility. Additionally, the system recorded a temperature‐independent degassing process caused by the large gradient between groundwater and atmospheric carbon dioxide that is limited to the proximity of the spring. This study cautions on the risk of assuming continuous deposition when studying laminated tufa sediments and highlights the potential of their stable isotope records to provide hydrological information of their aquifers during the past.     

基于GIS的鄂尔多斯白垩系盆地浅层地下水水质分布规律研究

文章以地下水质量标准为基础,结合鄂尔多斯白垩系盆地水资源现状,构建了研究区地下水水质评价指标体系,并对国标中部分指标限值提出了修正建议。通过建立浅层地下水水质模糊综合评价模型,对研究区地下水水质进行了综合评价,并以GIS为平台,对水质空间分布状况及其规律进行了研究。结果表明:总硬度、硫酸盐、溶解性总固体、氯化物指标的水化学分布对研究区地下水水质的影响最为明显,同时,盆地浅层地下水水质总体上相对较好,大部分地区地下水水质优于Ⅳ类,完全满足生活生产用水要求。     

GIS based groundwater modeling study to assess the effect of artificial recharge: A case study from Kodaganar river basin,Dindigul district,Tamil Nadu

Groundwater is a dynamic and replenishable natural resource. The numerical modeling techniques serve as a tool to assess the effect of artificial recharge from the water conservation structures and its response with the aquifers under different recharge conditions. The objective of the present study is to identify the suitable sites for artificial recharge structures to augment groundwater resources and assess its performance through the integrated approach of Geographic Information System (GIS) and numerical groundwater modeling techniques using MODFLOW software for the watershed located in the Kodaganar river basin, Dindigul district, Tamil Nadu. Thematic layers such as geology, geomorphology, soil, runoff, land use and slope were integrated to prepare the groundwater prospect and recharge site map. These potential zones were categorized as good (23%), moderate (54%), and poor (23%) zones with respect to the assigned weightage of different thematic layers. The major artificial recharge structures like percolation ponds and check dams were recommended based on the drainage morphology in the watershed. Finally, a threelayer groundwater flow model was developed. The model was calibrated in two stages, which involved steady and transient state condition. The transient calibration was carried out for the time period from January 1989 to December 2008. The groundwater model was validated after model calibration. The prediction scenario was carried out after the transient calibration for the time period of year up to 2013. The results show that there is 15 to 38% increase in groundwater quantity due to artificial recharge. The present study is useful to assess the effect of artificial recharge from the proposed artificial structures by integrating GIS and groundwater model together to arrive at reasonable results.     

基于信息熵的岩溶水监测网优化:以徐州市典型水源地为例

在各级水利与自然资源部门地下水监测数据共享机制逐步完善背景下,针对日益凸显的原有监测系统中存在的监测井布局不合理问题以及岩溶含水系统具有的非均质性和各向异性特征,选取徐州市丁楼-茅村和七里沟2个典型水源地,分别采用互信息-距离(T-D)和最大信息最小冗余(MIMR)模型对研究区监测网信息冗余性和最优监测井组合进行了研究...     

基于植被结构分析法的生态植被与地下水关系研究——以鄂尔多斯盆地内蒙古能源基地为例

生态植被与地下水关系研究是干旱半干旱地区地下水合理开发利用的基础。以植被空间分布和地下水埋深为基础资料,本文尝试提出大尺度生态植被与地下水关系半定量化分析的新方法——植被结构分析法,并以鄂尔多斯盆地内蒙古能源基地为例进行了示范研究。利用植被结构图分析法,可在定量研究生态植被与地下水关系基础上,统计分析地下水开发后生态植被出现演替的临界水位,并预测生态植被的整体演化趋势。