To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect...To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.展开更多
The aim of this paper is to illustrate the benefits,and challenges towards providing multifunctional urban green spaces.The results are based on critical analysis of study findings from different cities in Europe,Amer...The aim of this paper is to illustrate the benefits,and challenges towards providing multifunctional urban green spaces.The results are based on critical analysis of study findings from different cities in Europe,America and to a lesser extent in Asia.Inner-city green spaces are especially important for improving air quality through uptake of pollutant gases and particulates which are responsible for respiratory infections.Due to their amenity and aesthetics,green spaces increase property value.To ensure multifunctional role of urban a green space is achieved,in particular the social and psychological role,certain standards of quantity,quality and distribution within the urban area should be adequately established.Green spaces need to be uniformly distributed throughout the city area,although each does not need to be extremely large but should be large enough to accommodate the city population.展开更多
基金Projects PGSD3-334033-2006 supported by the Natural Sciences and Engineering Research Council of Canada2007-2008 by the Canadian Forest Service of Natural Resources
文摘To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.
文摘The aim of this paper is to illustrate the benefits,and challenges towards providing multifunctional urban green spaces.The results are based on critical analysis of study findings from different cities in Europe,America and to a lesser extent in Asia.Inner-city green spaces are especially important for improving air quality through uptake of pollutant gases and particulates which are responsible for respiratory infections.Due to their amenity and aesthetics,green spaces increase property value.To ensure multifunctional role of urban a green space is achieved,in particular the social and psychological role,certain standards of quantity,quality and distribution within the urban area should be adequately established.Green spaces need to be uniformly distributed throughout the city area,although each does not need to be extremely large but should be large enough to accommodate the city population.
