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451.
K C. Gan T A. McMahon I. C. O'Neill 《Journal of the American Water Resources Association》1990,26(3):443-450
ABSTRACT: For a set of 81 catchments in southeast Victoria, Australia, predictive equations were developed by least squares regression of the mean and coefficient of variation of annual Streamflow against a variety of rainfall and physiographic parameters. The data were also divided into subsets according to catchment size, subregion, or record length of investigate if the relationships differed significantly between subsets. Only the catchment area and some rainfall statistical parameters were found to be significant. Streamflow parameters predicted by the regression equations were used to estimate storage requirements in ungauged catchments. The influence of errors in the Streamflow parameters on the storage error was examined. 相似文献
452.
Dilip Mathur Eric S. McClellan Susan A. Haney 《Journal of the American Water Resources Association》1988,24(1):159-167
ABSTRACT: The effects of variable discharges during the summer on the dissolved oxygen (DO) content and water temperature upstream and downstream of the Conowingo Hydroelectric Power Station were investigated. The DO dynamics are controlled primarily by meteorological factors that are independent of the mode of hydrostation operation. DO stratification occurred during the summer in Conowingo Pond, but thermal stratification was not observed. The magnitude and duration of off-peak discharges including a run-of-the-river operation did not affect DO stratification in Conowingo Pond; little vertical mixing occurred. However, strong winds and/or high river flows temporarily destroyed DO stratification. The run-of-the-river operation or off-peak continuous discharge schemes did not provide better DO conditions downstream of the hydrostation than the peaking operation with intermittent off-peak releases. A statistical model predicted that a DO of 5 ppm occurs 0.6 miles downstream of the powerhouse when the natural river flow is consistently greater than 15,000 cfs and water temperature is less than 80°F. A mean daily DO of at least 4 ppm was predicted to occur over 80 percent of the time during the 92-day summer period. Farther downstream (1.3 miles from the powerhouse) a mean daily DO of at least 4 ppm was predicted to occur 90 percent of the time in summer. 相似文献
453.
Robert J. Houghtalen Jim C. Loftis 《Journal of the American Water Resources Association》1988,24(2):427-434
ABSTRACT: A modified dynamic programming (DP) approach that is called aggregate state dynamic programming (ASDP) is presented to optimally operate irrigation water delivery systems. ASDP can be applied to multiple reservoir systems without encountering dimensionality problems. In addition, the random nature of water supply and consumptive crop demands can be incorporated into the technique. A case study is presented to display the application of ASDP. Using a sum-of-squared shortages objective, ASDP out performs a traditional separation technique and approaches the theoretical (ideal) optimum. Problem settings that are conducive to the use of ASDP and limitations of the technique are presented. 相似文献
454.
Nathan Buras 《Journal of the American Water Resources Association》1985,21(6):1013-1020
Designing a surface reservoir involves the concept of reservoir yield. This concept embodies three basic information items: hydrologic regime, active storage volume, and reservoir release policy. In the actual case presented below, the magnitude of the active storage was prescribed by a legal procedure, so that the planning issue became that of determining the reservoir yield given the hydrological information. A stochastic dynamic programming model was formulated to derive a schedule of seasonal optimal reservoir releases and their respective probabilities of occurrence. This schedule is the reservoir yield. The yearly cycle was divided into three seasons representing the actual climatic conditions, and conditional probabilities linking streamflows in consecutive seasons were estimated. An operating policy was postulated, based on the same set of legal decisions that prescribed the active storage volume, and target reservoir releases were assumed. Similarly, target storages at the end of each season were set up. The optimizing/ minimizing criterion in the dynamic programming formulation was the sum of squares of deviations of actual releases and final storage volumes from their respective targets. 相似文献
455.
456.
2006年2月4日起,浙江省温州市文成县连续发生了多起有感地震,其中最大的震级为Mt4.6。地震发生后,中国地震局派遣的工作组对文成县的水库大坝进行了现场调查。这里介绍了地震的概况和现场调查的情况,以及基于地震监测和日常监测(坝体变形、坝体表面检查等)的结果,对坝体的安全性进行了评估,并提出了一些建议。 相似文献
457.
458.
尾矿库安全评价中的科学问题及评价方法探讨 总被引:9,自引:5,他引:9
尾矿库的安全稳定在矿山的安全生产和环境保护中具有十分重要的意义。尾矿库安全评价应该研究坝及其附属构筑物的安全状况,评价尾矿库的安全等级。本文立足于尾矿库工程的实践经验,探讨了尾矿库安全评价中应该涉及的科学问题,并对其相应的评价方法进行了探讨,指出了尾矿库安全评价应该采用的基于有限元理论的定量评价方法。本文认为排水不良和地震液化是影响尾矿坝稳定性的重要因素,应该在评价过程中给予重点的关注和研究。此外,在尾矿库的安全评价中,应更多地采用有限元数值计算方法研究上述科学问题。 相似文献
459.
460.
准噶尔盆地红87井区克上组沉积相特征 总被引:1,自引:1,他引:0
本文在对准噶尔盆地红山嘴油田红87井区各井所取的三叠系克上组(T2k2)岩芯观察描述及室内粒度分析的基础上,根据沉积相标志确定红山嘴油田红87井区三叠系克上组(T2k2)为辩状河沉积;通过单井划相、剖面相分析及平面相分析,编制出红87井区块三叠系克上组(T2k2)沉积相图,确认了沉积相控制了本区西部含油边界,为断层―岩性油气藏,解决了本区油气藏控制因素。 相似文献