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永城市浅层地下水水量丰富 ,水质良好 ,是一处理想的供水水源。本文运用模糊数学方法对该区浅层地下水水质进行了评价 ,确定了该区的环境背景值 ,并把该区分为 3个区。 相似文献
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引起浅层地下水病蚀的主要因素是高浓度的腐蚀性离子、溶解的气体及微生物。系统总结了水中各主要盐类,阴、阳离子、腐蚀性气体、生物细菌等,对金属及混凝土桩的腐蚀机理。为合理有效地采取保护措施提供参考。 相似文献
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本给出淮南市区浅层地下水的参数、补给和排泄资源的计算方法,且为制定用水方案,进行了多年均衡的计算,结果表明:浅层地下水平均每年还有6550万m^3资源供利用;在干旱年份里动用的储存资源,丰水年可以得到回补;浅层地下水合理位埋深应为3.5m。 相似文献
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本文通过沧州城区浅层地下水水文地质条件分析、浅层地下水开采资源量计算及结合沧州城区的实际情况来合理确定地下水位埋深、规范成井技术、浅井与建筑物安全距离等,通过工程实例来加以论证说明井与建筑物的安全距离,为沧州城市浅层地下水合理开发利用提供了科学依据。 相似文献
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结合铁路路堑实例浅述了山区沟谷浅层地下水在补给、径流和排泄等方面的特殊性,并阐述了针对浅层地下水特殊性而应采取的地质勘察方法,列举了由于对浅层水的特殊性认识不足给工程造成损失的实例。 相似文献
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堤垸是洞庭湖区最为重要的乡土景观类型,综合了农业生产、水利调控和聚落建设。人们在湖区的淤洲上建设堤垸来控制垸区的水位,以获得生活和生产空间;数百年的堤垸开垦历史,使得洞庭湖区几乎每一寸土地都经过了设计,积累了大量的水土整合经验。从风景园林的视角出发,将堤垸看作一种空间结构和文化表达的结果,而不单纯是水利工程的产物;通过系统分析和图解的方式,探索堤垸景观的空间设计法则,推断和解读这类景观的发生机制和特征。首先,简要阐述了洞庭湖区堤垸的围垦历史,理清了堤垸的发展脉络;其次,总结了湖区堤垸的现状空间分布情况;再次,从水利、垸田和聚落3个空间层,对不同空间层、不同尺度下的堤垸空间及其嵌套式的相互关系进行了解析;最后,总结出洞庭湖区的堤垸景观具有堤垸的更新性、尺度的层级性、形态的整体性等相关特征。上述分析可以使人们对洞庭湖区的堤垸景观有一个较为全面和深刻的理解,并获得堤垸保护与转型的线索。 相似文献
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大型桥梁工程由于两岸通视困难,用传统测量方法直接布设大桥工程控制网及进行大桥施工测量非常困难,因此GPS定位技术在大型桥梁工程的施工控制网测量中应用广泛。本文详细介绍了荆岳铁路洞庭湖大桥施工控制网的测量方案及实施情况,在测量中采用了GPS定位技术来建立施工控制网,整个施工控制网的测量包括施工平面控制网测量和施工高程控制网测量。结果表明获得的平面和高程控制测量成果精度均优于二等精度,可满足工程定测和施工测量应用的需要。 相似文献
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人类文明的发展进程与所处的环境密
不可分,探讨洞庭湖区新石器中晚期聚落时空分
异特征及影响因素有利于深入了解该时期人地
关系的演变,对史前文化遗产保护具有重要的
价值和意义。运用ArcGIS分析工具,结合因子
分析、地理探测器等方法探讨聚落时空变化规
律。得到结论:第一,新石器中晚期聚落倾向于
在地势平坦且距水较近的区域分布。气候特征
依次表现为大暖期、气温下降、气温回暖、恶化
期,聚落集中分布在年降水量1 150~1 250 mm、
等温21~23 ℃区域。三个文化时期可耕地区域主要分布在坡度0~25°,步行距离0~40 min范围内;第二,工具技艺进步为古人生产、生活及交通
提供了便利,聚落文化重心主要为大型聚落城址,且重心由洞庭湖西北向南迁移;第三,聚落选址
主要受地形因素影响,聚落规模空间分布受地形位指数和年均降水量因素的影响,并随时间变化
地形位指数因素的影响力逐渐减弱而年均降水量因素的影响力逐渐增强;第四,随着农业技术的
进步,聚落之间的社会矛盾激化,北方游牧民族南下,中原文化南迁,对长江流域社会文化发展产
生了重要的影响。 相似文献
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Laboratory experiments were conducted to characterize and quantify the capacity and kinetics of the combined effects of natural attenuation processes, such as adsorption, reduction, and precipitation, for hexavalent chromium [Cr(VI)] in a variable geochemical (i.e. fraction of organic carbon [foc], redox) environment of glaciated soils. Equilibrium attenuation terms: linear sorption (K(d)), estimated capacity, and non-linear Langmuir (K(L), Q) sorption parameters; varied over several orders of magnitude. The pseudo-first-order rate of disappearance of Cr(VI) from aqueous:soil slurries ranged from approximately 10(-5) to approximately 10(-1)/min. An operationally defined kinetic attenuation term, attenuation capacity (AC), describing the quantity of Cr(VI) disappearing from the slurries, ranged from 1.1 to approximately 12 microg Cr(VI)/g soil/7 days. The linear K(d)'s and estimated attenuation capacities were indirectly and directly related to increasing soil pH and foc, respectively. The AC values decreased and increased as a function of increasing soil pH and foc, respectively. The parameters determined in this work were used to evaluate the kinetics, capacity, and stability of chromium attenuation in the sub-wetland saturated soils in Hellerich (2004. A field, laboratory, and modeling study of natural attenuation processes affecting the fate and transport of hexavalent chromium in a redox variable groundwater environment. Ph.D. Dissertation, Department of Civil and Environmental Engineering, University of Connecticut-Storrs) using a statistical simulation framework. 相似文献
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Shin-ichi Onodera Mitsuyo Saito Takahiro Hosono Jun Shimada Rachmat Fajar Lubis Robert Delinom 《The Science of the total environment》2009,407(9):3209-3217
Asian megacities have severe pollution problems in both coastal and urban areas. In addition, the groundwater potential has decreased and land subsidence has occurred because of intensive groundwater pumping in urban areas. To prevent the adverse effects of urbanization on groundwater quality, it is necessary to confirm the changes in groundwater flow and contaminant transport caused by urbanization. We examined the effects of urbanization on contaminant transport in groundwater. The research areas were located around Bangkok, Thailand, and akarta, Indonesia, cities with populations of approximately 8 and 12 million, respectively. Each metropolitan city is located on a river delta and is adjacent to a bay. We measured the water level and collected water samples at boreholes at multiple depths (100 to 200 m) in 2004 and 2006 in Bangkok and Jakarta, respectively. The current hydraulic potential is below sea level in both cities because of prior excess abstraction of groundwater. As a result, the direction of groundwater flow is now downward in the coastal area. The Cl− concentration and δ18O distributions in groundwater suggest that the decline in hydraulic potential has caused the intrusion of seawater and shallow groundwater into deep groundwater. Concentrations of Mn and NO3−-N in groundwater suggest the intrusion of these contaminants from shallow to deep aquifers with downward groundwater flow and implies an accumulation of contaminants in deep aquifers. Therefore, it is important to recognize the possibility of future contaminant transport with the discharge of deep groundwater into the sea after the recovery of groundwater potential in the coastal areas. 相似文献
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Effects of human activities and urbanization on groundwater environments: an example from the aquifer system of Tokyo and the surrounding area 总被引:6,自引:0,他引:6
Hayashi T Tokunaga T Aichi M Shimada J Taniguchi M 《The Science of the total environment》2009,407(9):3165-3172
The Kanto plain that is the largest depositional plain in Japan has the largest urbanized area called Tokyo Metropolitan Area. This plain has experienced extensive groundwater withdrawals for water resources and human induced disasters such as land subsidence in the process of urbanization. Japanese national government and local governments have monitored groundwater levels and settlement of ground surface for about half a century. These data are useful not only for the prevention of these disasters but for the evaluation of the change of groundwater flow beneath the urbanized area. However, few hydrological and hydrogeological studies about the change of groundwater flow in this plain have been conducted until now except for several studies which were limited in areal extent. In this paper, changes of the distribution of hydraulic heads in the central part of this plain are discussed using the long-term groundwater level observation data to evaluate the change of groundwater flow. The temporal changes in the distribution of hydraulic heads in a major confined aquifer (the second aquifer) and the areal extent of the urbanized area for approximately 50 years can be summarized as follows. In the latter half of the 1950s, urban area was limited in the southern region of the study area and hydraulic head gradually declined from the northwest to the southeast in the study area. After the 1960s, urban area extended toward the north and groundwater in the northern part was largely abstracted until the 1980s. As a result, hydraulic heads in this area markedly declined. On the other hand, hydraulic heads in the southern part began to rise because of the restriction of groundwater withdrawals. In recent years, low hydraulic head area has been formed from the northern region to the central region. These results suggest that the groundwater flow which was affected by urbanization (groundwater withdrawals) has continued to change over several decades, even after the regulation of withdrawals, and hence, the continued monitoring of the groundwater environment is important for the sustainable use of groundwater resources. 相似文献
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根据洞庭湖区气候条件,结合湖区农村建筑能耗现状与农民经济水平,研究了适合湖区当前农村住宅施工技术与经济条件的门窗及屋顶的节能改造措施。 相似文献
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The equilibrium and kinetics of chlorophenol (CP) sorption by chitosan, poly D-glucosamine, were studied under simulated groundwater conditions. Lower temperature, from 25 degrees C to 15 degrees C and then 5 degrees C, markedly decreased the adsorption rates by a factor of 30-53% and 7-22%. Comparison between two types of chitosan, flakes and highly swollen beads, demonstrated that the maximum pentachlorophenol (PCP) uptake capacities in Langmuir and Freundlich models depend on the specific surface area of the particle. Low temperature (5 degrees C) significantly increased the PCP uptake capacity in comparison to higher temperatures (15 degrees C and 25 degrees C). PCP uptake capacity was halved at pH levels higher than 6.5, and NaCl concentrations greater than 1% blocked PCP sorption almost completely. Of five kinds of chlorophenols, i.e. 2,4,6-trichlorophenol (2,4,6-TCP), 3,4-dichlorophenol (3,4-DCP), 2,3-dichlorophenol (2,3-DCP), 2,6-dichlorophenol (2,6-DCP), 3-monochlorophenol (3-MCP), TCP had the maximum sorption efficiency on flake-type chitosan, followed by DCPs, and finally MCP (the three kinds of DCP, with the same elemental compositions, achieved similar sorption performances). 相似文献
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Jaeger Ø Grimstvedt A Frengstad B Reimann C 《The Science of the total environment》2006,367(1):437-440
Until 2005 the observation wells of the Norwegian Groundwater Monitoring Network in Quaternary aquifers were equipped with metal well points with brass lining. A laboratory leaching test using a new well point demonstrated that the well point material (galvanized iron pipe), the brass lining and the solder used to fix the lining could cause substantial contamination of the collected well water with a long list of chemical elements (Sn, Zn, Pb, Sb, Cd, Fe, Cu, Mn and Al), depending on well capacity, contact time water/well point and pH. Because groundwater chemistry is receiving increased attention in groundwater monitoring all wells were equipped with high density polyethylene (HDPE) points during the years 2004-2005. The HDPE points did not return any values above detection in a similar leaching test, with some minor values of Zn being the only exception. 相似文献