Indicadores para o verde urbano (IVU): proposta de uma implementação computacional para indicadores de densidade vegetada e densidade construída

Abstract

Urban density, which covers the population and construction spheres, is considered a fundamental parameter for understanding land use and occupation. In view of the current situation of the population densification process in urban centers, measuring it becomes indispensable with regard to its influence on the climatic scale and environmental quality of cities. In parallel, urban vegetation coverage is considered an essential element in the environmental and biophilic balance in the urban space, however the areas destined to these areas have suffered a progressive reduction in priority as well as in volume, both in consolidated areas and in areas of urban expansion, highlighting the need to reinforce / recreate tools aimed at regulating this parameter in urban legislation. In view of this, this work proposes a system of tools called Indicators for Urban Green (IUG), which is defined as the computational implementation composed of two proportion indicators that, through an algorithmic-parametric approach, allows establishing the existing correlation between the parameters of built density and vegetated density. The IUG consists of the Vegetable Density Indicator by Total Area (IDVAT) and the Vegetable Density Indicator by Constructed Density (IDVDC) formulated so that they can accurately measure the focus parameters of this research. To validate the proposed system, the IUG was applied in hypothetical (internal validation) and real (external validation) tests, the latter being carried out with the object of the Altiplano Cabo Branco neighborhood (João Pessoa - PB - Brazil). In the four hypothetical samples, four subtests were generated in different situations of vegetated areas for a comparative graphic understanding of the values found (diagram IUG). Then, in real sampling, the selected urban area was divided into six sub-areas that present different forms of building density and different types of vegetation cover. The indicators found in the real (current) scenario were: Altiplano 1: IDVAT = 0.06 / IDVDC = 0.4; Altiplano 2: IDVAT = 0.03 / IDVDC = 0.13; Altiplano 3: IDVAT = 0.05 / IDVDC = 0.19; Altiplano 4: IDVAT = 0.13 / IDVDC = 1.59; Altiplano 5: IDVAT = 0.11 / IDVDC = 0.92; Altiplano 6: IDVAT = 0.14 / IDVDC = 0.92. Then, two real-life scenarios of the neighborhood were chosen for the analysis of the trend scenarios and the construction of possible alternatives, in order to understand the values of the indicators in a situation of minimum proportion of vegetation cover with medium to large tree predominance. And, finally, a brief correlation of the indicators found was made with microclimate data from the city of João Pessoa (Ribeiro, 2013) that helped to visualize the relationship between the indicators with lower values and the areas with higher temperatures and devoid of vegetated density. Finally, it is expected that the evolution of the Indicators for Urban Green (IUG) can help provide data of fundamental importance to achieve greater levels of easing the climatic rigor through the minimum proportion between the vegetated and built volumes allocated in the urban space , as well as contributing to impact studies to avoid conflicts in the urbanization process and to promote the implementation of more equitable and environmentally qualified measures.