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971.
Lynne Tolland Jaime G. Cathcart S. O. Denis Russell 《Journal of the American Water Resources Association》1998,34(4):787-794
ABSTRACT. Estimates of peak flows, with specified return periods, are needed in practice for the design of works that affect streams in forested areas. In the province of British Columbia (B.C.), Canada, the new Forest Practices Code specifies the 100-year instantaneous peak flow (Q100) for the design of bridges and culverts for stream crossings under forest roads; and many practitioners are engaged in making such estimates. The state of the art is still quite primitive, very similar to the state of urban hydrology 30 years ago, when popular estimating techniques were used with little consideration given to their applicability. Urban hydrology then evolved on a much more scientific basis, such that within about a 10-year period, standard approaches to design were developed. Forest hydrology should follow the same pattern, at least as far as estimating design flows is concerned. Popular present day design procedures include the rational method and other empirical approaches based on rainfall data, as use of the standard flood frequency approach is limited by the paucity of relevant flow data. Estimating procedures based on peak streamflow measurements and statistics are likely to evolve, and these will include distinctions for rain, snowmelt, and rain on snow floods. Guidelines will also be developed for selecting and applying appropriate procedures for particular areas. 相似文献
972.
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974.
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977.
化学修饰电极在环境微量及痕量有机物分析中的应用 总被引:1,自引:0,他引:1
根据实验研究及国内外文献,从伏安及电位溶出分析,流动注射/液相色谱电化学检测,化学修饰电极生物传感器及化学修饰电极预富集—石墨炉原子吸收法联用等方面,重点综述了化学修饰电极在环境微量及痕量有机物分析中的应用。 相似文献
978.
Cai Jinlu 《环境科学学报(英文版)》1991,3(1):117-124
Over 2 million tons of chromate residues as hazardous wastes have been accumulated from chromate production processes during the past more than 30 years in China. Some serious pollution problems have been caused due to no appropriate technology and management. Approaches are reviewed to pollution control of chromate residues by utilizing them as secondary resources in this paper. In addition to legislation for pollution control, chromate residues can be used as raw materials to produce a great diversity of useful industrial products. Strategies are also recommanded for the resourcefulization of chromate residues. 相似文献
979.
980.
DerivingfreshwaterqualitycriteriaofsulphocyanicsodiumfortheprotectionofaquaticlifeinChinaZhangTongDepartmentofEnvironmentalE... 相似文献