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131.
流域水资源系统由降水产流,以及通过水文下垫面的转换,形成的地表径流和地下水流流组成。本文将复杂的沽河流域水 资源系统分解成多个子系统,利用频谱分析方法对各个水资源子系统的转换功能进行定量的分析刻画,并利用地下含水介质子系统的转换特征函数-频率响应函数求取水文地质参数,丰富了水文地质参数的获取途径。 相似文献
132.
陕西凤县庞家河金矿床基本地质特征及成矿作用分析 总被引:5,自引:0,他引:5
阐述了庞家河金矿床的地层、构造控矿特征,研究了矿床的化学成分、微量元素及矿体、矿石的基本特点,分析了矿石及矿石矿物黄铁矿的O、S、Pb稳定同位素组成;认为庞家河金矿的成矿介质水为同生建造水,成矿物质来源于围岩上沉盆统下东沟组,矿床类型为热水溶滤成因的微细浸染型。 相似文献
133.
沉积盆地流体—岩石相互作用研究的现状 总被引:17,自引:0,他引:17
沉积盆地流体-岩石相互作用研究主要是通过实验地球化学和岩石学,地球化学模拟方法开展的,综述了这一领域的研究现状,主要包括有机酸来源和分布及期 对矿物稳定性的影响,地层水成因与演化、烃类与岩石间的氧化还原反应、以及储层润湿性的变化等,并展望了其 发展趋势。 相似文献
134.
The focus of this research was to determine if abandoned mines constitute a major environmental hazard in the Black Hills. Many abandoned gold mines in the Black Hills contribute acid and heavy metals to streams. In some areas of sulfide mineralization local impacts are severe, but in most areas the impacts are small because most ore deposits consist of small quartz veins with few sulfides. Pegmatite mines appear to have negligible effects on water due to the insoluble nature of pegmatite minerals. Uranium mines in the southern Black Hills contribute some radioactivity to surface water, but the impact is limited because of the dry climate and lack of runoff in that area. 相似文献
135.
Porewater pressure increases in soil and rock from underground chemical and nuclear explosions 总被引:3,自引:0,他引:3
Wayne A. Charlie George E. Veyera Deanna S. Durnford Donald O. Doehring 《Engineering Geology》1996,43(4):225-236
A review and analysis of chemical and nuclear explosive-induced porewater pressure increases and induced rise in groundwater table elevations (groundwater mounding) is presented. Our analysis indicates that residual pore pressure increases and groundwater mounding can be induced by underground chemical and nuclear explosions to scaled distances of 879 m/(kt)1/3. This relationship is linear over seven orders of magnitude of explosive energy ranging from a 0.01 kg chemical explosion to a 100 kt nuclear explosion and is valid for a wide variety of saturated geological profiles. Underground chemical explosions, and probably underground nuclear explosions have the potential to induce liquefaction of water-saturated soils to scaled distances of about 260 m/(kt)1/3. 相似文献
136.
Yucca Mountain, the proposed site for the high-level nuclear waste repository, is located just south of where the present
water table begins a sharp rise in elevation. This large hydraulic gradient is a regional feature that extends for over 100 km.
Yucca Mountain and its vicinity are underlain by faulted and fractured tuffs with hydraulic conductivities controlled by flow
through the fractures. Close to and parallel with the region of large hydraulic gradient, and surrounding the core of the
Timber Mountain Caldera, there is a 10- to 20-km-wide zone containing few faults and thus, most likely, few open fractures.
Consequently, this zone should have a relatively low hydraulic conductivity, and this inference is supported by the available
conductivity measurements in wells near the large hydraulic gradient. Also, slug injection tests indicate significantly higher
pressures for fracture opening in wells located near the large hydraulic gradient compared to the opening pressures in wells
further to the south, hence implying that lower extensional stresses prevail to the north with consequently fewer open fractures
there. Analytical and numerical modeling shows that such a boundary between media of high and low conductivity can produce
the observed, large hydraulic gradient, with the high conductivity medium having a lower elevation than the water table. Further,
as fractures can close due to tectonic activity, the conductivity of the Yucca Mountain tuffs can be reduced to a value near
that for the hydraulic barrier due to strain release by a moderate earthquake. Under these conditions, simulations show that
the elevation of the steady-state water table could rise between 150 and 250 m at the repository site. This elevation rise
is due to the projected shift in the location of the large hydraulic gradient to the south in response to a moderate earthquake,
near magnitude 6, along one of the major normal faults adjacent to Yucca Mountain. As the proposed repository would only be
200–400 m above the present water table, this predicted rise in the water table indicates a potential hazard involving water
intrusion.
Received: 7 June 1996 / Accepted: 19 November 1996 相似文献
137.
The identifiability of parameters in a water quality model of the Biebrza River, Poland 总被引:1,自引:0,他引:1
The identifiability of model parameters of a steady state water quality model of the Biebrza River and the resulting variation in model results was examined by applying the Monte Carlo method which combines calibration, identifiability analysis, uncertainty analysis, and sensitivity analysis. The water quality model simulates the steady state concentration profiles of chloride, phosphate, ammonium, and nitrate as a function of distance along a river. The water quality model with the best combination of parameter values simulates the observed concentrations very well. However, the range of possible modelled concentrations obtained for other more or less equally eligible combinations of parameter values is rather wide. This range in model outcomes reflects possible errors in the model parameters. Discrepancies between the range in model outcomes and the validation data set are only caused by errors in model structure, or (measurement) errors in boundary conditions or input variables. In this sense the validation procedure is a test of model capability, where the effects of calibration errors are filtered out. It is concluded that, despite some slight deviations between model outcome and observations, the model is successful in simulating the spatial pattern of nutrient concentrations in the Biebrza River. 相似文献
138.
Quality Requirements for Fresh Waters: Water Quality Targets, Water Quality Objectives, and Chemical Water Quality Classification In the Federal Republic of Germany, water quality requirements for the protection of inland surface waters against hazardous substances are formulated on the basis of a quality targets derivation concept developed jointly by the Federal Government and the Federal States. The quality requirements were termed “water quality targets” in order to make it clear that the values derived are orientational values rather than legally binding limit values. The international comparison of quality requirements for surface waters shows that, on the whole, the national quality targets ensure a high level of protection. According to present scientific knowledge, impairments of uses, such as supply of drinking water, or risks to aquatic communities need not to be expected if the quality targets are complied with. A comparison of water quality data with the water quality targets makes it possible, on the one hand, to identify those substances whose inputs must be further reduced; on the other hand, it also shows that, for a number of substances, there is no need at present for concern over their adversely water quality. A further differentiation of the aquatic hazard potential of pollutants allows a water quality classification system to be developed on the basis of the quality targets derivation concept. The basic elements of this water quality classification system are presented, and its application is explained by way of examples. 相似文献
139.
Gas-chromatographic Determination of Polychlorinated Biphenyls in Water after Headspace Solid-phase Microextraction Headspace-analytical techniques are usually applied to the determination of easily volatile substances in water, whereas semivolatiles are generally isolated by liquid-liquid or solid-phase extraction. In the present paper, a method is presented for isolating high boiling polychlorinated biphenyls (PCB) using headspace solid-phase microextraction at elevated temperature. In spite of their low vapor pressure, the analytes are adsorbed very efficiently on a poly-dimethylsiloxane-coated fiber. Thus, in combination with GC/ECD, a very simple and sensitive solventless determination of PCB is accomplished. Using the simplest possible standard conditions, limits of determination in the lowest nanogram-per-liter range are achieved. Further increased sensitivity down to the ppq (parts per quadrillion) range is possible by stirring and increasing the sample volume and adsorption time. Moderate matrix effects have been observed in some surface and groundwaters. 相似文献
140.
Study of Sorptional Properties of the Cation Exchanger KB-2M with Macroreticular Structure for Recovery of Zinc Ions from Sewage and Rinsing Water Although a number of ion-exchange methods have been employed for the recovery of some transition metals from industrial effluents, knowledge about ion-exchange resins with macroreticular structure is poor. The present paper describes the mechanism of sorption on such exchangers and their application for recovery of zinc from sewage rinsing water. Ion exchanger of macroreticular structure are polymers with long-chained cross-linking agents. We have synthesized carboxylic ion-exchange resins by hydrolysis of copolymerisates of methyl acrylate with different cross-linking agents: divinylbenzene, divinyl sulfide, divinyl ester of ethylene glycol and divinyl ester of di- or triethylene glycol. The sorption process on modifications of the carboxylic resins KB-2 of various structure was studied with different methods: potentiometric titration, infrared spectroscopy, electron microscopy, X-ray structural analysis. The initial zinc concentration in rinsing water was 0.05 mol/L at pH from 3 to 6. For the sorption, 0.2…1.0 g of resin were equilibrated with 100 mL of zinc solution. After equilibrium (12 h), the resin was separated from solution. The zinc ions were determined by atomic absorption spectrometry after stripping with 100 mL of 10% sulfuric acid. The distribution ratio D was calculated (D: mmole of Zn sorbed per gram of resin divided by mmole of Zn per millilitre of solution). By means of infrared spectroscopy, the mechanism of sorption of zinc ions from rinsing water was determined. There may be a possibility of the formation of complexes in the cation-exchange resin phase. It was found out in this paper that the cation-exchanger KB-2M of macroreticular structure is the most effective for the sorption of the Zn2+-ions from sewage and rinsing water. 相似文献