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801.
Edwin T. Engmun 《Journal of the American Water Resources Association》1974,10(3):512-521
ABSTRACT: According to a concept known as partial area hydrology, watershed areas are separated into hydrologically active and passive subareas. The literature relating to the development of the partial area concept is reviewed briefly and the relationship of partial area hydrology to geology, soils, and micrometeorology is illustrated. The potential application of partial area hydrology is discussed with respect to present hydrologic techniques, future hydrologic models, urban hydrology, water quality, and water management. Suggestions for identifying and delineating the contributing areas are discussed. 相似文献
802.
本文对乌鲁木齐市大气环境质量及其发展趋势作了简要的分析,说明目前市大气属煤烟-沙尘型污染区,氮氧化物和二氧化硫随着国民经济能耗的增加有发展的趋势,其它污染物仍稳定在目前水平,或稍有下降. 相似文献
803.
804.
应用多目标决策中的TOPSIS法(即逼近于理想解的排序方法)对湖南长沙等十城市的大气环境质量进行评价,并与欧几里德贴近度法和上海指数法相比较,认为该评价方法对比较多个城市(或多个监测点,下同)的大气环境质量的优劣,比欧几里德贴近度法和上海指数法均优越. 相似文献
805.
806.
Geomorphologically appropriate rehabilitation measures were proposed to enhance the in-stream environment of the lowland River Idle, north Nottinghamshire, UK. However, the River Idle has multi-functional management requirements including those of flood defence so environmental enhancement must be pursued without significantly increasing the flood risk. Hydraulic testing of rehabilitation proposals is complicated because of the stringent assumptions about flow and morphology in ‘traditional’ hydraulic models. While new generation two- and three-dimension hydraulic models may overcome some of these problems, they are extremely data intensive, require advanced modelling capabilities and are, therefore, very expensive to apply. Also, they do not yet predict morphology-flow interactions adequately. As an alternative, several simple hydraulic models were applied to test the rehabilitation proposals, based on a fitness-for-purpose criterion.BENDFLOW was applied to fine tune the optimal siting of measures and to estimate the additional near-bank scour generated by proposed bend re-profiling. HMODEL2 and the FCFA method were used to test the impact on local channel conveyance capacities and HECRAS was applied to simulate the impact of the proposals on regional flood defence. Indicative results from the testing suggested a maximum increase in near-bank scour of 0·15 m in re-profiled bends, a loss of approximately 10% in flood conveyance locally due to deflector installation or reed and tree planting, and a 0·12 m increase in flood stage within the reach for a 15 year flood. The modelling results were acceptable to the management authority as an indication of an acceptable compromise between flood defence and conservation interests, and construction of the measures followed in 1996. It is clearly that it will require the results of post-project monitoring to indicate whether compromises made to the rehabilitation initiatives in order to satisfy flood defence requirements have unduly reduced their environmental enhancement potential but, for assessing the proposed methods, the models are recommended for use other lowland river environments. 相似文献
807.
Indicators and indices are important tools that assist decision makers to formulate and implement plans for management at local, national and international levels. Four indicators for hazardous waste management are described that have recently been adopted within the United Nations framework of Indicators of Sustainable Development. Although these four indicators will be useful tools, the need for a broader range of policy-relevant qualitative and quantitative indicators, proxy indicators and indices is outlined. The argument is advanced that in order for all nations to better manage the range of hazardous waste issues, including waste generation, export/import and disposal, a set of innovative indicators and indices is required. Useful indicators and indices are described that could be used to link and quantify likely environmental, ecosystem and health impacts and risks especially from hazardous waste disposal. Indicators are also suggested that could be used to illustrate the shift in industrial strategy away from end-of-pipe processes towards waste recycling, cleaner production and integrated life-cycle analysis. It was concluded that until the lack of reliable and harmonized data on hazardous waste is addressed, indicator development and use by national and international decision makers cannot readily be implemented. 相似文献
808.
809.
联苯代谢对微生物的生长胁迫及分裂抑制 总被引:1,自引:0,他引:1
以联苯/多氯联苯降解菌株R04(Rhodococcus sp.R04)和几种模式微生物为研究对象,利用高效液相色谱、荧光显微镜、扫描电子显微镜等分析微生物在联苯及其代谢物培养条件下细胞分裂和形态的变化.结果表明联苯及其代谢产物对红球菌R04和几种模式微生物细胞的分裂有抑制作用,并对部分微生物形态有影响.与前体-联苯及其代谢产物2-羟基-6-酮基-6-苯基-2,4-己二烯酸相比,2,3-二羟基联苯对G+、G-细菌,或是酵母细胞分裂都有较强的抑制和形态的改变.2,3-二羟基联苯导致R.R04和缺陷型R.R04细胞形成不完整隔膜的比例增加;造成96.4%的大肠杆菌BL21细胞表面凹陷,胞质内容物流失,菌体体积缩小;导致枯草芽孢杆菌89.6%的细胞体积明显缩小;导致金黄色葡萄球菌基本没有细胞能形成完整的分裂隔膜;导致红酵母细胞能进行出芽生殖的比例从64.2%降低到19.3%,但对其细胞形态无明显改变.联苯代谢物2,3-二羟基联苯对红球菌R04及其它微生物细胞分裂和增殖的抑制作用比其前体-联苯强,建议在研究环境化合物与微生物互作时,应考虑环境化合物代谢的毒性效应. 相似文献
810.
The relationship between diversity profiles,evenness and species richness based on partial ordering 总被引:4,自引:0,他引:4
Rousseau Ronald Van Hecke Piet NIjssen David Bogaert Jan 《Environmental and Ecological Statistics》1999,6(2):211-223
Problems with the notion of evenness, such as ambiguity, proliferation of indices, choice of indices, etc. can be overcome by a more fundamental, mathematical approach. We show that the Lorenz curve is an adequate representation of evenness. The corresponding Lorenz order induces a partial order in the set of equivalent abundance vectors. Also diversity can adequately be studied through a partial order and represented by a curve derived from the classical Lorenz curve. This curve is known as the intrinsic diversity profile (or k-dominance curve) and was introduced by Patil and Taillie (1979) and Lambshead et al. (1981). 相似文献