杭州市区地下水质量评价

采用综合评分法对杭州市区及近郊各类型地下水１９９７年的水质监测结果进行科学评价,为有关部门科学管理和合理开发利用地下水资源提供决策依据。     

黄河入海口水质评价与预测

对黄河入海口2004-2011年的水质进行评价与预测,采用灰色聚类法分析水体DO、CODMn、NH3-N 3项指标,总结水质年均变化情况.建立水质GM(1,1)灰色预测模型,用实际水质指标值检验其精度,并用此模型预测未来4年水质变化趋势.结果表明,2004-2015年期间,黄河入海口水质在2004-2007年波动较大,但将越来越好,CODMn、NH3-N呈下降趋势,DO、达标率呈上升趋势,并通过灰色关联分析方法分析水质变化原因以期对黄河入海口水质分析预测与水体保护工作提供参考.     

“多元素—多残留”检测在水质评价上的应用

“多元素——多残留”是利用等离子体发射光谱仪(ICP-AES)和气相色谱仪(GC)联合检测水中无机元素和农药残留的方法。灵敏度高,ICP-AES的平均回收率为96.3±4.4％,变异系数为3.15±0.12％,GC的平均回收率为95.1±1.55％,变异系数为3.22±0.21％。为水质检测、环境质量定位动态监测等提供了一种高效、快速、全面的新方法。     

江汉平原高砷地下水区地下水的化学特征及指示

以江汉平原中部的仙桃市、洪湖市2个砷中毒病区作为典型研究区,每处分别取了30户手压井水样,通过对样品中As浓度的分析、测试,并结合分析水样总溶解固体(TDS)、pH、氧化还原电位(ORP,以Eh表征)、SO2-4、NO-3、Cl-、HCO-3、Fe、Mn等指标,探讨了地下水中As浓度与化学指标间的相关性。结果表明,所取60份水样中,As质量浓度最高值为1.560mg/L,超过0.05mg/L的有17份水样,超标率为28%;研究区地下水pH为6.01~7.16,平均为6.56,明显偏酸性,Eh为13.6~75.3mV,平均为44.2mV,呈弱氧化性,该结果与中国山西大同盆地、山阴地区、内蒙古河套平原等原生高砷水地区有着明显的差异;水样的As浓度与TDS、HCO-3、Fe、Mn浓度呈正相关,与SO2-4、NO-3浓度呈负相关,研究区地下水环境是典型的高砷水赋存环境;水样中TOC质量浓度为2.35~5.32mg/L,平均为3.29mg/L,溶解性有机物对水体中As的迁移转化有着很重要的作用。     

基于模糊权物元理论的地下水水质评价模型构建及应用

在物元分析的基础上,结合模糊权重理论与层次分析方法,构建用于评价地下水水质的模糊权物元分析模型。应用此模型对徐州市的重要水源地——张集水源地的地下水水质进行了综合评价。选取数据较为完整的20个监测井的监测数据进行评价。结果表明,研究区的20个采样点水质为Ⅱ、Ⅲ级的占95%,绝大多数地下水水质较好,符合饮用水的要求。与投影寻踪法和模糊概率法的评价结果比较发现,得出的评价结果与以上2种评价结果基本一致。     

污灌区与非污灌区的地下水主要水质指标变化趋势及对比研究

通过对水文地质条件和天然条件下水质相似的一处非污水灌溉地区水与一处污水灌溉区地下水水质的对比研究，得出污水灌溉区地下水水质为差主要是由化肥和污水灌溉共同引起的，且非污灌区地下水质要好于污灌区的水质。污水灌溉对地下水的影响程度与化肥对地下水的基本相同。同时本文也独立地给出了污水灌溉和化肥对地下水质的影响规律。     

基于人工蜂群算法与BP神经网络的水质评价模型

针对BP网络水质评价模型的不足,引入人工蜂群(ABC)算法,将求解BP神经网络各层权值、阀值的过程转化为蜜蜂寻找最佳蜜源的过程,提出了一种新的结合人工蜂群算法的BP网络水质评价方法(ABC-BP)。并以2000—2006年渭河监测断面的10组实测数据作为测试样本对其水质进行了评价,实验结果表明该方法得到的水质评价结果准确,并具有很强的稳定性和鲁棒性。     

模拟优化模型在地下水监测布井中的应用

以北京市某农田用地地下水监测井为研究对象,基于农田水文地质参数建立了地下水多目标模拟优化模型。结合Monte Carlo分析法分析了地下水水流模型和溶质运移模型参数的不确定性,并求解了单口监测井的影响半径,最后借助NSGA-Ⅱ算法建立了两个目标函数之间的权衡关系。模型求解结果表明,监测系统可靠性目标最大为76.8%,对应的监测井数量最小为3口;当扩大污染羽的控制边界时,可以建立4口监测井。研究结果表明,模拟优化模型可以用于地下水监测井布井优化当中,建立两个目标函数之间合理的权衡关系,确定监测井的数量和位置,保证监测系统的可靠性。     

水质模型参数识别的遗传算法

Ｏ’ｃｏｎｎｏｒ模型是一个比广泛应用的Ｓｔｒｅｅｔｅｒ－Ｐｈｉｌｉｐｓ模型更精确的水质模型,由于该模型参数率定的困难性,限制它在实际中应用。     

浅层地下水遥感找水模型研究

采用遥感-数据-模型相融合的方法,建立了浅层地下水推断模型。该模型克服了以往勘察方法费用高、效率低、周期长的不足,从未知出发,由面到点,层次分明,衔接有序。经实地考察验证,该模型精度较准,效率较高,具有实用性,不仅可以宏观、快速、高效地确定浅层地下水的分布和范围,而且可以降低费用,缩短周期,起到事半功倍的作用,为进一步找水工程的布置提供依据,确定找水方向,避免找水的盲目性。     

Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m ditch transect. Through continuous discharge measurements and weekly water quality sampling, we directly quantified the flow route contributions to surface water discharge and solute loading. Our multi-scale experimental approach allowed us to relate these measurements to field-scale NO₃ concentration patterns in shallow groundwater and to continuous NO₃ records at the catchment outlet. Our results show that the tile drains contributed 90-92% of the annual NO₃ and heavy metal loads. Considering their crucial role in water and solute transport, enhanced monitoring and modeling of tile drainage are important for adequate water quality management.     

WebGIS与一维水质模型的集成研究

结合江苏省环保信息系统的建设,讨论WebGIS与一维水质模型集成的关键技术问题,阐明模型计算中评价河段截取、空间离散及空间数据重采样的方法和过程,对实现水环境模型的跨平台操作和数据信息共享作出了尝试,设计了基于浏览器方式的集成系统。     

A detailed field-based evaluation of naphthenic acid mobility in groundwater

An anaerobic plume of process-affected groundwater was characterized in a shallow sand aquifer adjacent to an oil sands tailings impoundment. Based on biological oxygen demand measurements, the reductive capacity of the plume is considered minimal. Major dissolved components associated with the plume include HCO₃, Na, Cl, SO₄, and naphthenic acids (NAs). Quantitative and qualitative NA analyses were performed on groundwater samples to investigate NA fate and transport in the subsurface. Despite subsurface residence times exceeding 20 years, significant attenuation of NAs by biodegradation was not observed based on screening techniques developed at the time of the investigation. Relative to conservative tracers (i.e., Cl), overall NA attenuation in the subsurface is limited, which is consistent with batch sorption and microcosm studies performed by other authors. Insignificant biological oxygen demand and low concentrations of dissolved As (< 10 µg L^− 1) in the plume suggest that the potential for secondary trace metal release, specifically As, via reductive dissolution reactions driven by ingress of process-affected water is minimal. It is also possible that readily leachable As is not present in significant quantities within the sediments of the study area. Thus, for similar plumes of process-affected groundwater in shallow sand aquifers which may occur as oil sands mining expands, a reasonable expectation is for NA persistence, but minimal trace metal mobilization.     

Hydrochemistry of urban groundwater, Seoul, Korea: the impact of subway tunnels on groundwater quality

Hydrogeologic and hydrochemical data for subway tunnel seepage waters in Seoul (Republic of Korea) were examined to understand the effect of underground tunnels on the degradation of urban groundwater. A very large quantity of groundwater (up to 63 million m³ year^− 1) is discharged into subway tunnels with a total length of 287 km, resulting in a significant drop of the local groundwater table and the abandonment of groundwater wells. For the tunnel seepage water samples (n = 72) collected from 43 subway stations, at least one parameter among pathogenic microbes (total coliform, heterotrophic bacteria), dissolved Mn and Fe, NH₄⁺, NO₃⁻, turbidity, and color exceeded the Korean Drinking Water Standards. Locally, tunnel seepage water was enriched in dissolved Mn (avg. 0.70 mg L^− 1, max. 5.58 mg L^− 1), in addition to dissolved Fe, NH₄⁺, and pathogenic microbes, likely due to significant inflow of sewage water from broken or leaking sewer pipes.Geochemical modeling of redox reactions was conducted to simulate the characteristic hydrochemistry of subway tunnel seepage. The results show that variations in the reducing conditions occur in urban groundwater, dependent upon the amount of organic matter-rich municipal sewage contaminating the aquifer. The organic matter facilitates the reduction and dissolution of Mn- and Fe-bearing solids in aquifers and/or tunnel construction materials, resulting in the successive increase of dissolved Mn and Fe. The present study clearly demonstrates that locally significant deterioration of urban groundwater is caused by a series of interlinked hydrogeologic and hydrochemical changes induced by underground tunnels.     

Natural and anthropogenic factors affecting the groundwater quality in the Nandong karst underground river system in Yunan, China

The Nandong Underground River System (NURS) is located in a typical karst agriculture dominated area in the southeast Yunnan Province, China. Groundwater plays an important role for social and economical development in the area. However, with the rapid increase in population and expansion of farm land, groundwater quality has degraded. 42 groundwater samples collected from springs in the NURS showed great variation of chemical compositions across the study basin. With increased anthropogenic contamination in the area, the groundwater chemistry has changed from the typical Ca–HCO₃ or Ca (Mg)–HCO₃ type in karst groundwater to the Ca–Cl (+ NO₃) or Ca (Mg)–Cl (+ NO₃), and Ca–Cl (+ NO₃ + SO₄) or Ca (Mg)–Cl (+ NO₃ + SO₄) type, indicating increases in NO₃⁻, Cl⁻ and SO₄²⁻ concentrations that were caused most likely by human activities in the region. This study implemented the R-mode factor analysis to investigate the chemical characteristics of groundwater and to distinguish the natural and anthropogenic processes affecting groundwater quality in the system. The R-mode factor analysis together with geology and land uses revealed that: (a) contamination from human activities such as sewage effluents and agricultural fertilizers; (b) water–rock interaction in the limestone-dominated system; and (c) water–rock interaction in the dolomite-dominated system were the three major factors contributing to groundwater quality. Natural dissolution of carbonate rock (water–rock interaction) was the primary source of Ca²⁺ and HCO₃⁻ in groundwater, water–rock interaction in dolomite-dominated system resulted in higher Mg²⁺ in the groundwater, and human activities were likely others sources. Sewage effluents and fertilizers could be the main contributor of Cl⁻, NO₃⁻, SO₄²⁻, Na⁺ and K⁺ to the groundwater system in the area. This study suggested that both natural and anthropogenic processes contributed to chemical composition of groundwater in the NURS, human activities played the most important role, however.     

河流水环境中的非突发性水质风险模型研究

把影响水质模型的随机因素看成一个具有零均值的维纳过程,建立一个研究非突发性水质风险的随机微分动态模型,并对该维纳过程强度进行了估值。研究表明,水环境中的随机因素是引起非突发性风险的一个重要原因。     

土壤渗滤处理系统运行控制的模拟研究

通过建立地下水数学模型,回答了土壤渗滤工程运行控制中的两个难点问题:(1)工程运行水力负荷.当工程地块周边存在河流时,河流水位低时,有助于增加水力负荷,反之则降低水力负荷;实际土壤运行面积的增加和独立运行单元之间的间距增加也能够增加工程运行水力负荷.(2)地下水水质监测井的优化布设.模拟工程运行后地下水水质空间分布特征,在地下水水质最不利的位置和其他特别关注的位置布置监测井,从而能够以具有典型代表性且数目较少的监测井达到准确评估工程对地下水水质影响的目的.     

Reliability evaluation of groundwater quality index using data-driven models

Environmental Science and Pollution Research - A trustworthy evaluation of the groundwater quality situations for different usages (i.e., drinking, industry, and agriculture) can definitely improve...