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901.
Abstract Water saving and developing water conservation society are the two key strategies both for wise water allocation and sustainable utilization. The paper analyses the connotation of water saving and water conservation society. Essentially, water saving means freeing up water from non-beneficial uses and providing it to some more productive uses. Basic principles for setting indicator are presented by providing efficient use of water, considering social issues and ecological protection. An integrated assessing water saving system aiming at more sustainable and efficient consumption is given considering unbalanced social and economic development in regions and basins. The hierarchy Indicator system provides qualified tools to the practice of water conservation and evaluates the value for water conservation society construction. 相似文献
902.
This study aimed at clarifying the impact of deforestation and afforestation on the quality of life in a village in Sichuan Province, China. We devised a conceptual model of bioresource production and use based on quantified energy flow. The basic structure of the model has three sectors: production, use, and externals. We developed comprehensive methodology to quantify the model. Bioresource use per person in 1997 was 3.7 GJ for food, 10.2 GJ for fodder, 0.2–0.4 GJ for building material, 12.8 GJ for fuel, and 1.8 GJ for fertilizer, totaling 28.6–28.8 GJ.We used four environmental indicators to evaluate bioresource production and use: a biological productivity indicator, a use-efficiency indicator, a supply–demand balance indicator, and a self-sufficiency indicator. Use of these indicators showed that supply-demand balance of fuel was dramatically improved from 30% to 85% by afforestation, but 99% of bioresource use still depends on domestic products. Thus, it is necessary to improve biological productivity and promote the efficient use of bioresources to achieve sustainable living in the area. Massive deforestation in the 1950s caused a direct shortage of building material and fuel wood. The shortage of wood led to a stagnation in the rebuilding of houses, and fuel wood was substituted with crop residues. Because crop residues had been used for fertilizer and fodder, their use as fuel caused a shortage of fertilizer and fodder. This was an indirect impact of deforestation on peoples quality of life. 相似文献
903.
Rufus K. Guthrie Ure A. Anugwelem Ernst M. Davis 《Journal of the American Water Resources Association》1981,17(6):1005-1007
ABSTRACT: Escherichia coli. Streptococcus faecalis, Salmonella typhimurium, and Staphylococcus aureus were tested in pure culture and in various combined mixed cultures to determine effects of the presence of carbaryl in water. Oxygen uptake of E. coli and S. typhimirium was stimulated by five mg/L carbaryl when mixed together, but no stimulation was observed when either organism was tested alone or with other bacteria. In mixed culture the survival time of S. faecalis was reduced in the presence of five mg/L carbaryl; however, the survival time of both S. aureus and S. typhimurium was increased in the presence of five mg/L carbaryl. Implications of these results are discussed. 相似文献
904.
城市人居环境可持续发展评价研究——以大连市为例 总被引:20,自引:0,他引:20
城市人居环境的可持续发展是现代城市建设和发展的最终目标。本文建立了城市人居环境可持续发展的评价指标体系及评价模型 ;通过对大连市城市人居环境实地调查 ,运用Fuzzy方法对大连市城市人居环境可持续发展进行评价分析 ,确定了城市人居环境发展阶段 ;根据评价结果 ,结合大连市人居环境的具体情况 ,提出了大连市城市人居环境可持续发展的对策 相似文献
905.
The relatively scarcity of flat or moderately sloping land in Central Appalachia make reclaimed surface mined lands attractive for agricultural uses. A reclaimed surface coal mine in southern West Virginia was placed under grazing management during the 1984 and 1985 growing seasons. Discharge was collected from summer-grazed watersheds of about 2.8 ha and 8.9 ha and analyzed, by the membrane-filtration method, for fecal coliforms (FC). Prior to grazing, in 1984, FC counts were < 20/100 ml. During the grazing season, FC ranged from <0/100 ml to> 1000/100 ml in 1984 and from 0/100 ml to > 2500/100 ml in 1985. FC counts remained high during warm periods for several months after grazing ceased. It was concluded that the bacteriological quality of receiving streams was impacted by grazing the reclaimed area and recommended standards for point sources were often exceeded; however, the FC counts did not appear to be any greater than what would have been expected from grazed, undisturbed areas. Reclaimed surface mine areas in Appalachia have the potential to be a valuable “flat land” resource and grazing appears to be an alternative post mine land use that affects bacteriological water quality in a similar manner as “natural” pastures. However, good management practices may be necessary to avoid bacterial contamination of adjacent bodies of water. 相似文献
906.
MUCT-MBR工艺反硝化除磷脱氮研究 总被引:3,自引:2,他引:1
自行设计的双反应器MUCT-MBR简化了MUCT工艺,将反应池由5个简化到2个,减小了工艺占地面积,并且采用膜过滤取代二沉池出水,操作简单,出水安全可靠.针对MUCT-MBR工艺脱氮除磷性能,尤其是反硝化除磷功能进行研究.结果表明,当进水C/N/P比在33.3/5/1~25/5.5/1范围内,整个实验过程中COD、 TN和TP平均去除率分别达到89.3%、 75.4%、 79.2%;且膜出水不受污泥沉降性的影响.缺氧段的反硝化吸磷是MUCT-MBR工艺除磷的关键,系统运行至第58 d,系统中反硝化除磷菌(DPAOs)所占比例达84.2%,反硝化除磷占系统总磷去除的67.07%. 相似文献
907.
基于聚糖菌和聚磷菌竞争的代谢模型及影响因素 总被引:5,自引:0,他引:5
聚糖菌的富集已成为造成EBPR强化生物除磷系统非稳定运行的重要因素之一.本文基于活性污泥数学模型ASM.2D的生物除磷代谢模型,围绕化学计量学和动力学阐述了聚磷菌PAOs胞内糖原的代谢途径以及聚糖菌GAOs在厌氧和好氧条件下的代谢模型,揭示了2类微生物的竞争本质.同时,对比分析了影响代谢模型化学计量学参数的若干因子,如碳源类型、温度、pH条件和污泥龄SRT等;结果发现,这些因素对PAOs和GAOs的代谢模型系数具有重要的影响作用,并进而决定着2类微生物的竞争优势.此外,针对目前对两类微生物的竞争主要集中于厌氧代谢的现状,提出今后的研究重点应放在好氧/缺氧机理方面. 相似文献
908.
普通及指示克里格法在水稻禁产区筛选中的应用 总被引:4,自引:0,他引:4
在对农产品产地进行监测基础上,以川东南水稻生产区为研究对象,探讨了普通克里格法及指示克里格法在农产品产地禁产区筛选中应用的可行性.研究区土壤监测统计结果表明,川东南水稻生产区以重金属Cd污染为主,区域Cd最高值为0.53mg·kg-1;监测点超过<土壤环境质量标准>(GB 15618-1995)2级标准值的比例达34.98%.探索性分析结果显示,研究区土壤Cd异常值较少,土壤Cd监测值及指示值实验半变异函数均为各向同性,采用人工干预条件下的基台值自动拟合法拟合普通及指示克里格实验半变异函数,并根据交叉验证结果确定分别采用带块金值的指数模型及带块金值的球形模型套合结构拟合普通及指示克里格实验半变异函数.通过普通和指示克里格插值结果筛选水稻禁产区后,应用误判率法评估了两种方法应用于水稻禁产区筛选的优缺点.结果表明,普通克里格法训练数据集的误判率为3.89%,验证数据集误判率为26.09%;指示克里格法训练集的误判率为0.78%,验证数据集误判率为21.73%,指示克里格法的估计精度要优于普通克里格法,更适合于研究区水稻禁产区的筛选. 相似文献
909.
910.
利用层次分析法理论建立了京杭大运河苏州高新区段的水环境承载力的指标体系,通过专家打分,采用层次分析法计算出了各指标的权重,以定量的形式确定了各指标对水环境承载力的影响大小,为流域水环境承载力的研究提供了参考依据。 相似文献