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991.
Regional distribution pattern of groundwater heavy metals resulting from agricultural activities 总被引:18,自引:0,他引:18
Contaminations of groundwater by heavy metals due to agricultural activities are growing recently. The objective of this study
was to evaluate and map regional patterns of heavy metals (Cd, Zn and Cu) in groundwater on a plain with high agricultural
activities. The study was conducted to investigate the concentration of heavy metals and distribution in groundwater in regions
of Shush Danial and Andimeshk aquifers in the southern part of Iran. Presently, groundwater is the only appropriate and widely
used source of drinking water for rural and urban communities in this region. The region covers an area of 1,100 km2 between the Dez and Karkhe rivers, which lead to the Persian Gulf. For this study, the region was divided into four sub-regions
A, B, C and D. Additionally, 168 groundwater samples were collected from 42 water wells during the earlier months of 2004.
The flame atomic absorption spectrometry (AAS-Flame) was used to measure the concentration of heavy metals in water samples
and the Surfer software was used for determination of the contour map of metal distribution. The results demonstrated that
in all of the samples, Cd and Zn concentrations were below the EPA MCLG and EPA secondary standard, respectively. However,
the Cu contents of 4.8 % of all samples were higher than EPA MCL. It is also indicated that the concentrations of metals were
more pronounced at the southern part of the studied region than at the others. The analysis of fertilizers applied for agricultural
activities at this region also indicated that a great majority of the above-mentioned heavy metals were discharged into the
environment. Absence of confining layers, proximity to land surface, excess agricultural activities in the southern part and
groundwater flow direction that is generally from the north to the southern parts in this area make the southern region of
the Shush plain especially vulnerable to pollution by heavy metals than by other contaminants. 相似文献
992.
江源县位于吉林省东南部,处于长白山西麓,行政管辖隶属于吉林省白山市,具有丰富的矿产和旅游资源。近年来,由于经济的发展和人类工程活动的增强,加剧了区内地质灾害的形成,地质灾害对当地的经济发展和人民生命财产安全造成损失和潜在威胁。本文对该县的地质环境作了详尽的阐述,在此基础上对研究区内的泥石流、滑坡、地面塌陷、不稳定斜坡等地质灾害的发育特征和形成条件作了全面的分析研究,总结出它们的发展规律,同时对该县进行了地质灾害经济损失现状评估和预测评估,最后结合当地经济条件与地质灾害现状,给出了较为切实可行的地质灾害防治对策。 相似文献
993.
The distribution of several minor and trace elements mainly in fresh (dominating TDS 160–400 mg/l) groundwater of Latvia have
been investigated by the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) technique. An evaluation of results of about
700 analyses leads to the conclusion that concentrations of these elements is influenced by: pH–Eh conditions, groundwater
residence time and diffuse contamination, whereas the role of water-bearing sediments is of secondary importance. Most trace
elements are characterised by low mobility under alkaline and reducing conditions; concentrations in confined aquifers are
much smaller than the Maximum Permissible Values for drinking water. The strongest anomalies of REE, Al and P were found in
shallow groundwater around the former agrochemical storehouses. 相似文献
994.
Helmut Kerndorff Stephan Kühn Thomas Minden Dagmar Orlikowski Thomas Struppe 《Environmental Geology》2008,55(2):291-301
The aim of this research project is to identify, characterize and quantify natural attenuation (NA) processes in groundwater
affected by emissions of abandoned waste disposal sites in Berlin-Kladow/Gatow, Germany. It is part of the funding priority
called KORA established by the Federal Ministry for Education and Research (BMBF) to explore the extent to which NA can be
used for remedial purposes for varied forms of soil and groundwater contamination. Information on the emission behaviour of
individual parameters is generated on the basis of hydrogeochemical comparison of 20 years old and new data. Using groundwater-modelling
and CFC-analysis, information on the transport and retention of pollutants in groundwater is compiled. The microbial colonization
of contaminated aquifers is characterized by molecular biological methods [polymerase chain reaction (PCR) and denaturing
gradient gel electrophoresis (DGGE)] to differentiate between contaminated and not contaminated zones. 相似文献
995.
This paper deals with groundwater hydrology at a prominent fracture zone landslide slope (Nuta–Yone landslides) in Japan with
an objective to explore an efficient method for the application of landslide stability enhancement measures. The correlation
analyses between the hydrological parameters and ground surface movement data at this landslide resulted in low correlation
values indicating that the geological formation of the area is extremely complex. For the purpose of understanding the groundwater
flow behavior in the landslide area, a three-dimensional transient groundwater flow model was prepared for a part of the landslide
slope, where the levels of effectiveness of applied landslide stability enhancement measures (in the form of multilayered
deep horizontal drains) are different, and was calibrated against the measured water surface elevations at different piezometer
locations. The parameter distributions in the calibrated model and the general directions of the groundwater flow in terms
of flow vectors and the results of particle tracking at the model site were interpreted to understand the reasons for variations
in effectiveness of existing landslide stability enhancement measures and to find potentially better locations for the implementation
of future landslide stability enhancement measures. From the modeling results, it was also understood that groundwater flow
model can be effectively used in better planning and locating the landslide stability enhancement measures. 相似文献
996.
Unconsolidated sand, gravel and clay deposits near Beihai and in the Leizhou Peninsula in southern China form an unconfined
aquifer, aquitard and a confined aquifer. Water and soil samples were collected from the two aquifers in the coastal Beihai
area for the determination of chemical compositions, minerals and soluble ions. Hydrogeochemical modeling of three flow paths
through the aquitard are carried out using PHREEQC to determine water–rock interactions along the flow paths. The results
indicate that the dissolution of anorthite, fluorite, halite, rhodochrosite and CO2, and precipitation of potash feldspar and kaolinite may be occurring when groundwater leaks through the aquitard from the
unconfined aquifer to the confined aquifer. Cation exchanges between Na and Ca can also happen along the flow paths. 相似文献
997.
998.
999.
云南省迪庆香格里拉盆地地热资源勘查物探方法的应用 总被引:1,自引:2,他引:1
香格里拉盆地地处滇藏地热带,具有形成热储、地热的基本条件.通过该区区域地质、物化探资料的分析研究,选择了盆地东北部为重点工作区,部署了超长电磁波探测、大地电磁测深、高精度磁测.初步查明了研究区寻找热储目标的重点应为受断裂影响的深埋藏碳酸盐岩储热储水层.总结出了香格里拉盆地6种类型的地频谱曲线,其中目标层--含水碳酸盐岩反映为E层曲线特征:较高振幅、基值高、波形活跃、变化幅度大.含水破碎灰岩电阻率100~200Ωm,与围岩存在明显电性差异.综合分析推测香格里拉县地热勘查靶区应在三村-达拉一带,富含水层深度1900~2600m,厚度约700m. 相似文献
1000.
河北平原地下水氘过量参数特征 总被引:11,自引:0,他引:11
氘过量参数是由Dansg aar d提出的一个新概念,它被定义为:d= δD-8δ18O。河北平原地下水氘过量参数有三个特征: ( 1)地下热水的氢和氧同位素组成显示出热交换的态势,d 值随地下水年龄增大而减少。( 2)在同一地区,d 值随着地下水埋深加大而增大。( 3)在同一含水层内,沿着地下水的路径,从补给区到承压区, d 值随着地下水年龄增大而增大。我们认为, d 值虽然是地下水年龄的函数,但最好和3 H、3H- 3He、14 C、36 Cl和4 He测年结果结合使用。 相似文献