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841.
为探究高温作用对泥岩盖层密封性的影响,从理论上剖析储气库盖层产生热应力的3种形式,在室内试验的基础上,分析泥岩在高温环境下力学损伤程度和盖层物性封闭评价指标随温度变化特征.结果表明:高温环境下泥岩整体结构性能降低,400℃左右是泥岩在周期热应力作用下损伤的阈值温度;高温作用会显著改变泥岩盖层物性封闭特征,400℃左右是... 相似文献
842.
Janos J. Bogardi Lucien Duckstein 《Journal of the American Water Resources Association》1992,28(1):75-88
ABSTRACT: Two simple interactive techniques are developed and illustrated by means of two different real-life examples in Thailand. The first technique, Evolutionary Sequential Multiobjective Problem Solving (ESEMOPS), is an open-ended algorithm designed for planning problems with discrete alternatives. ESEMOPS helps the decision making group (DMG) develop progressively a preference function over the alternatives. The algorithm follows an evolutionary “breeding” strategy to generate a small set of good alternative solutions. This heuristic search, which does not guarantee that the adopted ‘satisfactum’ is an efficient solution leads to plausible results when applied to the planning of the Mae Khlong-Chao Phraya interbasin water transfer and irrigation system. The second algorithm, Search Beam Method (SBM) is essentially a series of one-dimensional searches for an efficient point along a “beam” passing through a goal point. Repeated search towards displayed goal points is leading to a set of quasi non-dominated solutions. SBM is illustrated by the Ubol Ratana reservoir control problem with the two conflicting objectives of energy generation and irrigation water supply. Neither ESEMOPS nor SBM require that weights, utilities, or pairwise tradeoffs be assessed. These features have been very much appreciated by a real DMG presented with the two techniques. 相似文献
843.
冷原子吸收法测定油田废水中汞时,精密度、回收率较差,试验中采用JCG-Ⅰ型测汞仪进行了条件试验、精密度、准确度和最低检出限试验,结果说明在所选定的条件下方法是可行的。 相似文献
844.
郑根保 《长江流域资源与环境》1993,2(2):182-186
水库移民学是一门正在酝酿形成之中的新兴综合性学科。本文结合水库淹没处理的经验教训,分析了水库移民学的研究对象——水库移民的科学范畴,得出:水库移民是因兴建水库而产生的由淹没区和淹没影响区迁移到安置区的“人——自然——社会——经济系统”以及这个系统的动态演化过程。它具有系统性、动态演化性、被动性、主体性、补偿性、开发性、环境调适性和自行融合性等八个基本特征。 相似文献
845.
Jehng-Jung Kao Hong-Jyh Hong 《Journal of the American Water Resources Association》1996,32(5):1067-1079
ABSTRACT: Parameter uncertainties exert a significant effect on nonpoint source pollution (NPS) modeling results. A decision made on the basis of such results may thereby be inappropriate. In this work, the parameter uncertainty is analyzed to explore an improved modeling procedure. Drainage patterns generated from digital elevation data and rainfall are the major parameters examined. A case study for the watershed of the Posan off-stream reservoir is implemented. A significant spatial variation of NPS distribution simulated with a drainage pattern generated from varied methods is observed. The effects of rainfall randomness on the spatial loading distribution are assessed and computed based on a Monte Carlo simulation. The proposed procedure is capable of improving the quality of modeling results and the decision for an appropriate control strategy. 相似文献
846.
三峡库区奉节县土地承载力与移民安置 总被引:4,自引:0,他引:4
人口环境容量的研究是提高移民安置工作科学性的基础,通过对四川奉节县人口及土地资源调查数据的分析,考察了三峡水库淹没对库区人口环境容量的缩减;对库区不同区域,不同类型的土地对人口的承载能力进行定量分析;研究了移民安置与环境容量的关系;探讨了通过大农业和通过城镇化、非农化等方式安置农村移民的对策。 相似文献
847.
ABSTRACT: A stochastic dynamic programming model is applied to a small hydroelectric system. The variation in number of stage iterations and the computer time required to reach steady state conditions with changes in the number of storage states is investigated. The increase in computer time required to develop the storage probability distributions with increase in the number of storage states is reviewed. It is found that for an average of seven inflow states, the largest number of storage states for which it is computationally feasible to develop the storage probability distributions is nine. It is shown that use of the dynamic program results based on a small number of storage states results in unrealistically skewed storage probability distributions. These skewed distributions are attributed to “trapping” states at the low end of the storage range. 相似文献
848.
涔天河水库灌区土壤资源特点及其合理利用 总被引:1,自引:0,他引:1
彭佩钦 《长江流域资源与环境》1995,4(1):29-32
对涔天河水库灌区土壤资源现状,特点进行了调查研究,对土壤资源利用中存在的问题进行了剖析,并提出了合理利用土地资源,提高土壤生产力的措施。 相似文献
849.
Jung Hyun Choi Seon‐A. Jeong Seok Soon Park 《Journal of the American Water Resources Association》2007,43(6):1444-1454
Abstract: This research investigates possible impacts of enlarged water body according to dam reconstruction on the hydrodynamics and water quality of the reservoir using a laterally averaged, two‐dimensional hydrodynamic and transport model, CE‐QUAL‐W2. The lake was formed by the artificial dam in 1983 for agricultural water supply and is currently under consideration of reconstruction so as to expand the volume of reservoir for flood control as well as water supply in downstream areas. To calibrate and validate the model, field‐collected data were compared with model predictions for water level fluctuations and water temperature during the years of 2001 (from January to December) and 2003 (from March to November). The model results showed a good agreement with field measurements both in calibration and verification. Utilizing the model, impacts of dam reconstruction on the thermal hydrodynamics and turbid current were predicted. From the model results, dam reconstruction limited the depth of thermal stratification below 10 meter and formed steep temperature gradient between epilimnion and hypolimnion. The restricted thermal stratification persisted up to the end of September. This result indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. In addition, the restricted thermal stratification caused vertical circulation of water mixing lower than 10 meter and isolated the upper water layer from the lower water layer which increased the volume of hypolimnetic water with low temperature. The vertical circulation near the surface also mitigated propagation of density plume within the depth of 10 m which would remain the hypolimnetic water clean. 相似文献
850.
Ted L. Napier Silvana M. Camboni W. Richard Goe 《Journal of the American Water Resources Association》1986,22(1):11-18
ABSTRACT: Data were collected from residents of a rural community at two time periods to assess attitudes toward uses made of a reservoir which had been recently constructed in the area. The findings revealed that attitudes became significantly more favorable for flood control, water supply, and recreation uses of the reservoir. Attitudes toward fish and wildlife conservation use were not significantly different over time but these uses were perceived positively at both time periods. The data were also analyzed in the context of a vested interest perspective using cross-sectional design. The findings demonstrated that the theoretical model used to guide the investigation was quite useful in predicting attitudes toward the four uses examined. 相似文献