Aplicacao do geoprocessamento no estudo da impermeabilidade urbana

The environmental impact of urbanization due to the surface impervious growing and inadequacy of urban occupation induces to a significant increase of inundation events in every urban center. Hence, this paper focuses the concept of impervious surface as an indicator of environment impact, expressed through the changing of pervious areas in impervious areas by paving cover or building occupation. It is taken as a case study 13 areas pertaining to Canoas City, Rio Grande do Sul – Metropolitan area of Porto Alegre, Brazil. The main goal of the methodology process is to achieve information about types of land cover for studying the association with urban impermeability level. Therefore, the manipulation of municipal digital cartographic base of Canoas City with aerial photographs, through the geoprocessing applied in geographic information system toolbox (GIS), allows this research to produce data about of urban impervious areas generation. These results could help the urban settlement planning to reduce the impervious cover and the hydrological impact in its implementation.

Representação espacial na cognição ambiental urbana : aspectos de uso do solo e presença social

In the present paper different representations of urban character that influence environmental cognition are tested. Two main features involved in urban identity are the functional and social aspects of urban environment. Land use of lots is aggregated into different intensity measures that explore functional characterization of urban spaces. Social presence related to residential use and movement in urban space are also evaluated by intensity and social-economic characteristics. All selected attributes come from normal governmental data bases. Thus, one of the challenges is to transpose/interchange data from different scale units into a unique spatial representation unit, creating a common spatial base in a GIS environment.

Análise da acessibilidade urbana para o planejamento da urbanização de interesse social

An analysis of housing issues in the city of Canela (RS, Brazil) has been made in 2008 as part of the development of the Master Plan for Housing. The present paper deals with one component of this analysis, which is the assessment of urban accessibility for low-income population, and its consequences on the treatment of the problem of current shortage of low-income housing and the future demand from population growth until 2020. A three steps method is applied: (i) urban mobility is assessed and mapped on the basis of the road system and the routes of public transport; (ii) accessibility to different urban services, such as public education and health, recreation, consumption and jobs are measured and mapped considering the location of urban facilities, population distribution divided by income and age, and urban mobility; (iii) one map for urban accessibility is produced as a result of the weighted combination of accessibility to different urban facilities. This final urban accessibility map is then overlayed to empty urban lots with size and land value appropriate to low-income housing, and a simulation of their development over the future has been made. The lots with higher accessibility were selected, and the impact of urban development was assessed on the capacity of education facilities. Based on this study, we made some preliminary suggestions for widening places in some schools, the need for a new education facility (location and size) and the extension of public transport for an area with low accessibility.