ESQUEMAS DE ZONIFICACIÓN AMBIENTAL PARA LA PLANIFICACIÓN REGIONAL URBANA

La práctica y teorías de la planificación urbana han avanzado históricamente hacia  la  incorporación de  temas  y análisis  intersectoriales,  fundamentalmente aquellos en  relación con  la base  territorial y el ambiente. En materia de zonificación urbana se han  hecho esfuerzos por  incorporar  la variable ambiental a  la planificación urbana. El presente artículo hace un recuento general de  la evolución del concepto de zonificación tradicional  hacia  la    zonificación  ambiental  territorial,  la  macrozonificación  y  la zonificación  por  rendimiento.  Finalmente  plantea  el  acercamiento  metodológico planteado  como  parte  de  la  estrategia  de  la  Fase  III  del  Plan Nacional  de Desarrollo Urbano  de  Costa  Rica  en  relación  con  la  macrozonificación  por  rendimiento,  como ejemplo de  la puesta en práctica de  las más  recientes herramientas en  la planificación urbano- regional de un Área Metropolitana (PRUGAM). Abstract:The Urban Planning practice and  theory  has  historically developed  towards the inclusion of more comprehensive themes and analyses, fundamentally those that are environmentally  and  territorially  related. Within  this  context,  urban  zoning  has made significant efforts  to  incorporate the environmental component  in planning. The article makes  a  general  account  of  the  evolution  of  zoning  from  its  traditional  form  to environmental land zoning, macro zoning and performance zoning. Finally it establishes the  Costa  Rica’s National Urban Development  Plan methodological  approach  for  its phase III with regards to performance macro zoning as an example of putting the more recent  zoning  and  planning  theories  to  practice  in  a  regional  Plan  for  a metropolitan area.

Air pollution levels measured at traffic hot spots : Brisbane urban corridor study

Air pollution levels were monitored continuously over a period of 4 weeks at four sampling sites along a busy urban corridor in Brisbane. The selected sites were representative of industrial and residential types of urban environment affected by vehicular traffic emissions. The concentration levels of submicrometer particle number, PM2.5, PM10, CO, and NOx were measured 5-10 meters from the road. Meteorological parameters and traffic flow rates were also monitored. The data were analysed in terms of the relationship between monitored pollutants and existing ambient air quality standards. The results indicate that the concentration levels of all pollutants exceeded the ambient air background levels, in certain cases by up to an order of magnitude. While the 24-hr average concentration levels did not exceed the standard, estimates for the annual averages were close to, or even higher than the annual standard levels.

How can land and urban development make houses healthier?

Traditionally, the main focus of the professional community involved with indoor air quality has been indoor pollution sources, preventing or reducing their emissions, as well as lowering the impact of the sources by replacing the polluted indoor air with "fresh" outdoor air. However, urban outdoor air cannot often be considered "fresh", as it contains high concentrations of pollutants emitted from motor vehicles - the main outdoor pollution sources in cities. Evidence from epidemiological studies conducted worldwide demonstrates that outdoor air quality has considerable effects on human health, despite the fact that people spend the majority of their time indoors. This is because pollution from outdoors penetrates indoors and becomes a major constituent of indoor pollution. Urban land and transport development has significant impact on the overall air quality of the urban airshed as well as the pollution concentration in the vicinity of high-density traffic areas. Therefore, an overall improvement in indoor air quality would be achieved by lowering urban airshed pollution, as well as by lowering the impact of the hot spots on indoor air. This paper explores the elements of urban land and vehicle transport developments, their impact on global and local air quality, and how the science of outdoor pollution generation and transport in the air could be utilized in urban development towards lowering indoor air pollution.