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Demin  A. P. 《Water Resources》2000,27(6):670-687
The development history of the accounting system of water supply in the USSR is presented. Various statistical abstracts of 1970–1998 on the water supply in the Russian Federation are analyzed. Reference data are shown to be in need of correction. The dynamics of waste, mine, and drain water disposal are considered. The change in water quality is shown to be inadequate to the reduction in the discharge of pollutants.  相似文献   

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崔庆  徐建华  单伟 《湖泊科学》2004,16(Z1):163-166
黄土高原水土保持现状减水约10亿m3,但大规模综合治理后耗水量是多少?本文通过多种方法分析,2010年、2030年和2050年水土保持生态建设需耗水约20亿m3,40 亿m3和50亿m3.  相似文献   

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A New Method for Collecting Core Samples Without a Drilling Rig   总被引:1,自引:0,他引:1  
A new piston sampler allows the collection of high-quality core samples from sand, silt or clay, up to depths of 18 meters. The sampler is operated by a one- or two-person crew without a drilling rig. The sampler and ancillary equipment fit easily into a half-ton truck, making this a highly portable sampling system. Other advantages include minimal mechanical disturbance and precisely known sample depth. Casing is not required to maintain an open corehole below the water table and drilling fluid is not used in the corehole, so the solids and pore water of the sample should not be contaminated by foreign fluids. High-quality samples for physical, geochemical, and microbiological characterization of the subsurface are easily obtained with this new device.  相似文献   

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黄河水资源贫乏,水污染严重,水资源供需矛盾日益尖锐,黄河流域水资源保护面临着诸多的困难和压力.新《水法》的颁布,给黄河水资源保护带来新的机遇和挑战,依法建立法制化、社会化的流域与区域相结合的水资源保护管理体系,完善法规,建立健全执法体系,以水功能区划管理为重心,实施入河总量控制,建立和完善重大水污染事件快速反应机制,加强水质监测机制与技术创新,加强水资源保护前期和科研工作,建设水资源保护信息管理系统,采取多部门联合治污等项措施,是做好黄河流域水资源保护工作的重要前提和任务.  相似文献   

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Water demands for backwash purposes were investigated in an existing water treatment plant. It was noticed that the period of reduction of the concentration of suspension in outflow to values as high as 800, 700, 600, 500 mg/l was correlated with the total mass accumulated in a filter. However, at the end of the backwash the suspension concentration in outflow had a more occasional character and no documented correlation existed. It was also found that the period of a filter backwash established arbitrarily by the staff of the water treatment plant depended on the total dry mass of deposit accumulated.  相似文献   

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ModTech: a GIS-enabled Ground Water Modeling Program   总被引:1,自引:0,他引:1  
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– Five aquatic ecosystems, Yamuna river, Krishna river Eastern Kalinadi, Kadrabad drain and Peacock lake have been studied with reference to diversity and physico-chemical characteristics and biological indices. – A list of species have been selected with reference to polluted, mildly polluted or unpolluted water conditions. Though it is difficult to call any species strictly indicator species, certain species of Bacillariophyceae, bottom biota and Entomostraca can be regarded as indicative species. – The quantitative distributions of the species of different groups have been analysed statistically. Margalef's Community Diversity Index (d), Shannon Weaver Function, coefficient of rank correlation and partial and multiple correlation coefficient were calculated as to find out the order of precedence in different taxonomical groups. – The linear regression against BOD and the whole biocenosis were calculated, which indicate the relation as diversity d=6.7854 –0.0080 BOD±0.9695 where r2= B=0.7365. Similarly, multiple linear regressions were also calculated using diversity against BOD, pH and temperature for each aquatic ecosystem. – All these observations indicate that diversity of organisms can be used to measure the water pollution intensity.  相似文献   

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This paper presents the mass, momentum and energy equations that can be applied to nonisothermal flow in porous media. These equations are derived by taking a suitable volume average of the microscopic equations. The resulting macroscopic equations are then appropriate for experimental comparison.  相似文献   

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The purpose of this article is to discuss the evolution of wave energy, enstrophy and action for atmospheric Rossby waves in a variable mean flow. The presentation is theoretical, but does not represent original research; rather, it is pedagogic in nature. The work of a number of people has been drawn together into a unified account, with much of the algebra implicit in previous work made explicit here. The central results are that wave energy is conserved only when there are no spatial variations in the mean flow, and wave action is conserved even in the presence of such variations as long as they are not in the longitudinal direction. Finally, wave enstrophy is conserved in the presence of arbitrary (slow) mean flow variations.  相似文献   

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