基于变权欧式距离模型的阜新农村地下水质综合评价

为克服综合评价模型中因子权重定量的不确定性与主观性,体现出同一地下水质因子在不同地下水水源地评价单元中存在的差异性,采用地下水质因子污染贡献率确定各地下水质因子的权重,改进了欧式距离模型,建立了农村地下水源地水质评价的变权欧式距离模型,并以阜新市典型乡镇后新秋镇、苇子沟乡、哈尔套镇3个农村地下水水源地为评价对象,将2013年阜新市农村地下水水源地水质实测数据、标准数据规范化,运用数轴模型距离尺度进行地下水水质分割。评价结果与F值法结果基本吻合,变权欧式距离模型的距离尺度能够提高地下水水质评价结果的定量灵敏度,变权欧式距离模型具备一定的环境参数评价充分性、一致性及有效性。     

河北沧州地区地下水中盐分的时空演化及其机理探讨

沧州地区多年来大量开采深浅层地下水,破坏了咸淡水层的界面,并导致咸水面下移,对下部含水层有较大的影响。本文以沧州地区地下水中的盐分为研究对象,在历史资料收集分析、野外水文地质调查、取样测试分析的基础上,对比分析了历史阶段和现阶段地下水TDS的空间分布规律,探讨了沧州深层和浅层地下水中TDS的空间分布特征、演化特点及成因。结果表明:从1980年到现在30余年,沧州地区深、浅层地下水的TDS均呈升高趋势,浅层水TDS高的区域从滨海向区域中部延伸,深层水TDS仍为滨海中部西部;补给量减少是浅层地下水TDS增大的主要原因,深层地下水开采是深层地下水TDS增大的主要原因。可通过有效解决深层地下水超采问题,同时,对TDS高的微咸水和咸水进行综合开发利用等措施来改变沧州区域地下水TDS升高趋势。     

甲苯污染场地基于人体健康的风险评估

某化工生产车间历史上发生甲苯泄漏,造成了现场的土壤和地下水污染。采用基于人体健康的风险评估以分析污染对敏感受体的风险,并确定污染物修复目标值和修复范围。结果表明,风险评估过程模型计算复杂,涉及参数众多,运用可信的风险评估商业软件可以快速模拟各种模式并进行计算,大大提高工作效率。     

大连市地下水环境质量状况及污染防治对策

本文充分利用大连市已有地下水资料,通过对大连市地下水各项监测指标进行分析,利用Arc GIS反距离加权空间插值法将点状数据转化为面状数据,进行大连市地下水质量的区域评价。根据地下水水质8项监测指标的分析数据,利用Arc GIS空间分析平台,得到大连市地下水污染评价图,从而得出大连市各行政区域地下水存在不同程度污染的结论。最后通过对大连市地下水污染来源和防治现状的研究,提出大连市地下水污染防治对策及建议。     

广西平果铝赤泥堆场对岩溶含水层污染风险评价

为了评估赤泥堆场建设对地下含水层的污染,对堆场周边进行水文地质勘察.采用地球物理探测、钻探、示踪试验等多种技术手段查明堆场周边岩溶管道的分布规律及管道水的流向,并采用压水试验和注水试验测得含水层的渗透系数,在此基础上通过数值模拟计算出各月流经堆场下方的岩溶水流量.采用达西定理计算得到赤泥淋沥液穿透防渗层的时间约为42 a,远超堆场的服务年限(25 a),表明堆场防渗层的设计是合格和可靠的.在赤泥堆场建设20 a后再次对堆场下游及其周边的溶潭水进行地下水水质监测,结果也证实堆场下游及其周边地下水未因赤泥渗漏而污染.     

Assessing seasonal variation of fluoride in groundwater for irrigation uses through hydro-geochemical and multivariate statistical approach

Since a considerable amount of fluoride (Fl) intake also takes place through the ingestion of foods that are grown in the contaminated soil and irrigated with elemental contaminated water, this may lead to higher risk from Fl-mediated toxicity. Therefore, in the present study, a systematic delineation and characterization of Fl in agricultural tube wells in Unnao District, India, were carried out to examine seasonal variations of this element using graphical and multivariate statistical approach. The results suggested that different natural hydro-geochemical processes such as weathering of silicates, carbonates, and various ion exchange processes are the key factors responsible for the geochemistry of the groundwater in addition to the alkalinity of water. Of the water sampled, 27.3% and 18.2% were contaminated with Fl exceeding the desirable limit of 1 mg/L as prescribed by Bureau of Indian Standards during pre-monsoon and post-monsoon season. Fluoride displayed a significant positive correlation during both seasons and the water type of the majority of the samples in both seasons was bicarbonate.     

Terbuthylazine Contamination of the Aquifer North of Vicenza (North-East Italy) (5 pp)

- DOI: http://dx.doi/10.1065/espr2006.01.016 Background and Goal Agricultural practices can affect the quality of aquifers given that they are often located in cropped areas, so significant amounts of pesticides can be found in the water. In particular, triazine herbicides are always carefully checked by the official monitoring systems. The goal of this study was to find the mean concentration of terbuthylazine in an Italian aquifer and to set up a mass balance of this compound. Methods Terbuthylazine concentrations in the aquifer were measured in various check-wells during 1998–2004, and the value of censored data were estimated using a Gompertz inverse in order to evaluate the overall mean concentration. The total terbuthylazine load in the recharge area was calculated on the basis of surveys of cropped land and the main weed control techniques applied in the area. Data on aquifer water balance were obtained from previous studies. Results and Discussion The herbicide terbuthylazine applied in the recharge zone can be transported by surface water and enter the aquifer. Detected concentrations were always well below the EU drinking water limit and the fraction that can reach the groundwater under normal cropping practices is small, very likely less than 0.2%. Recommendations and Outlook The use and application rates of pesticides should be strictly regulated in recharge areas. Vegetated buffer strips can mitigate the impact of herbicides on surface water through reducing drift and early-spring runoff. Attention should also be paid to the fate of the main metabolites from soil biochemical processes.     

台南温泉井流量异常与南黄海地震关系初析

江苏省东台市台南温泉井１３年来共有三个时段的流量有较大幅度的异常都对应了南黄海一平方度内发生的４次４６～６３级地震。本文对该井的地质构造条件、观测方法、震前异常特征、干扰因素的排除、映震效能、异常机理、流量异常与地震三要素的关系等作了介绍和讨论。     

Nitrogen Subsidies from Hillslope Alder Stands to Streamside Wetlands and Headwater Streams,Kenai Peninsula,Alaska

We examined nitrogen transport and wetland primary production along hydrologic flow paths that link nitrogen‐fixing alder (Alnus spp.) stands to downslope wetlands and streams in the Kenai Lowlands, Alaska. We expected that nitrate concentrations in surface water and groundwater would be higher on flow paths below alder. We further expected that nitrate concentrations would be higher in surface water and groundwater at the base of short flow paths with alder and that streamside wetlands at the base of alder‐near flow paths would be less nitrogen limited than wetlands at the base of long flow paths with alder. Our results showed that groundwater nitrate‐N concentrations were significantly higher at alder‐near sites than at no‐alder sites, but did not differ significantly between alder‐far sites and no‐alder sites or between alder‐far sites and alder‐near sites. A survey of ¹⁵N stable isotope signatures in soils and foliage in alder‐near and no‐alder flow paths indicated the alder‐derived nitrogen evident in soils below alder is quickly integrated downslope. Additionally, there was a significant difference in the relative increase in plant biomass after nitrogen fertilization, with the greatest increase occurring in the no‐alder sites. This study demonstrates that streamside wetlands and streams are connected to the surrounding landscapes through hydrologic flow paths, and flow paths with alder stands are potential “hot spots” for nitrogen subsidies at the hillslope scale.     

地下水污染与人类健康

现代化的社会对地下水的污染问题是十分关切的。本文旨在介绍一些在地下水污染的控制和治理以及地下水污染所至的健康风险评价等方面的技术。