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101.
102.
以2005年为基准年,根据统计数据和发展目标分析了“十一五”期间新疆能源消费领域的节能潜力.结果显示,新疆万元GDP、万元工业增加值能耗均远高于全国水平,能源消费领域节能潜力为4 557.33×10^4t标准煤;石油加工、炼焦及核燃料加工业,石油和天然气开采业,电力、热力的生产和供应业,黑色金属冶炼及压延加工业,非金属矿物制品业,建筑节能,化学原料及化学制品制造业是新疆节能潜力较大的领域,且节能潜力依次减小,总节能潜力达3 348.48×10^4t标准煤;上述这些行业和领域内能耗均较高,建筑节能在节约资源的同时减少城市大气污染,是节能的优先领域. 相似文献
103.
104.
Abstract: Identifying relationships between landscape hydrogeological setting, riparian hydrological functioning and riparian zone sensitivity to climate and water quality changes is critical in order to best use riparian zones as best management practices in the future. In this study, we investigate water table dynamics, water flow path and the relative importance of precipitation, deep ground water (DG) and seep water as sources of water to a riparian zone in a deeply incised glacial till valley of the Midwest. Data indicate that water table fluctuations are strongly influenced by soil texture and to a lesser extent by upland sediment stratigraphy producing seeps near the slope bottom. The occurrence of till in the upland and at 1.7‐2 m in the riparian zone contributes to maintaining flow parallel to the ground surface at this site. Lateral ground‐water fluxes at this site with a steep topography in the upland (16%) and loam soil near the slope bottom are small (<10 l/d/m stream length) and intermittent. A shift in flow path from a lateral direction to a down valley direction is observed in the summer despite the steep concave topography and the occurrence of seeps at the slope bottom. Principal component and discriminant analysis indicate that riparian water is most similar to seep water throughout the year and that DG originating from imbedded sand and gravel layers in the lower till unit is not a major source of water to riparian zones in this setting. Water quality data and the dependence of the riparian zone for recharge on seep water suggest that sites in this setting may be highly sensitive to changes in precipitation and water quality in the upland in the future. A conceptual framework describing the hydrological functioning of riparian zones on this setting is presented to generalize the finding of this study. 相似文献
105.
D. G. Wallen 《Journal of the American Water Resources Association》1977,13(2):299-308
ABSTRACT: Data from three ice-covered stations in Lake St. Clair were collected to evaluate the effect of ice and related variables on phytoplankton production. Primary production, phytoplankton standing crop, irradiation and temperature were measured from January to April, 1973. Mean production values ranged from 0.74 mgC/m3/h at station 1 near Mitchell Bay to 3.4 mgC/m3/h in waters at stations 2 and 3 below the Thames River mouth. A similar pattern was observed in chlorophyll a concentration, the mean values ranged from 0.63 μg/1 at station 1 to 2.1 and 1.3 μg/1 at stations 2 and 3. Temperature stratification occurred at the three stations. However, the temperatures at station 1 were consistently more than a degree warmer than at the other two stations. Irradiation was low, having a mean value at the sampling depth of .075 ly/min. The data is interpreted to indicate that the ice-bound phytoplankton were adapted to the low irradiation. It is suggested that the variation observed between stations is related to the formation of a plume by the Thames River and differences in nutrient loads carried by the St. Clair and Thames Rivers. 相似文献
106.
Contamination of oxygen-consuming organics (OCOs) was one of the most serious problems in the Yellow River of China. This
study was conducted to analyze monitoring of the data on OCOs contamination for the river in 1980 and during 1992–1999 as
well as examining the effect of suspended solids (SS) on chemical oxygen demand (CODMn) and biochemical oxygen demand (BOD5) of river water. Several significant results have arisen from the study. First, CODMn and BOD5 of the river water showed an increasing trend from the upper to the lower reaches of the mainstream. BOD5 values of river water in 1992 were significantly higher than those in 1980 and showed an increasing trend during 1992–1999.
Second, OCOs in river water of the mainstream was attributed mainly to point sources; the ratio of point to non-point sources
of BOD5 was about 2.81. The load from point sources showed an increasing trend during 1992–1998. In contrast, the load from non-point
sources manifested a decreasing trend during this period; this was caused by the decreasing trend of SS content in river water.
The total load of BOD5 from point and non-point sources displayed an increasing trend during 1992–1998. Third, as the humic substances in SS can
hardly be biologically oxidized in natural conditions but can be oxidized by chemical oxidants such as potassium permanganate,
CODMn was not suitable for being regarded as a parameter reflecting the pollution degree of OCOs in river water with a high SS
content. 相似文献
107.
饮用水安全是最大的民生工程,也是自然资源管理研究的热点。基于实地调研、部门访谈和制度条文的梳理与分析,以苏州市太湖水源地为例研究湖泊型水源地管理体制。研究表明:我国水源地管理由国家、省、市、县的法律法规、规章和规范性文件构成相对完善的制度体系,具有水资源和水环境分割管理、流域管理和行政区管理交错的制度特征,初步具备了综合管理的架构;水源保护缺乏流域管治的思维,农村面源污染治理制度支撑不足;在管理手段上以命令控制型手段为主,经济激励与公众参与不足。建立水源地综合管理协调机制,完善经济激励手段,推进公众参与,实施水源地管理共同责任机制将有利于提高水源地管理效率 相似文献
108.
北京市地下水污染源荷载影响评价 总被引:1,自引:0,他引:1
在阐述地下水污染源荷载影响基本概念的基础上,介绍了污染源荷载影响评价的3大要素:污染荷载等级、含水层敏感性及地下水价值,说明了评价体系、指标和方法及过程。根据主要污染源荷载分析,结合地下水环境现状,对北京市进行了分区,提出污染源管理措施。 相似文献
109.
Trends in plant cover synanthropization along a plain-foothills-mountains gradient have been revealed in the reserve. Characteristics of plant communities in anthropogenically disturbed habitats, centers of concentration of anthropophytes and apophytes, and pathways of their migration are described. 相似文献
110.
针对农村面源污染日渐突出的问题,以农村饮用水源地黄沙港为例分析了农村面源污染的现状和成因,并从乡镇规划、生活污水处理工艺选择、畜禽水产业污染治理、农药化肥的施用、农业废弃物利用技术等方面提出防治措施。 相似文献