Shading analysis of urban squares using open-source software and free satellite imagery

Abstract

The purpose of the study is to develop a method for analyzing, from satellite imagery and GIS tools, the impact of shading from surrounding buildings on open public squares in a subtropical location in Brazil, in order to assist and provide subsidies for urban planning. The method integrates open data, spatial data, and GIS simulation tools for the analysis of shading profiles on winter and summer solstices, and spring equinox. Different types of spaces were analyzed for the current configuration of adjacent buildings, starting with a historic square, Japan Square, in Curitiba. The analysis for 25 urban public squares with the current height configuration showed that four of them had more than 50% of their surface area shaded more than 3 h in winter solstice. The detailed analysis of a possible future scenario for one of the squares evaluated showed that the study of the impact of future constructions on open-air public spaces is important and necessary, especially when vertical growth is allowed in cities such as Curitiba, characterized by a cold winter, when solar access is largely recommended. The method proved to be applicable and reliable, and can be useful for the initial stages of urban planning, as well as for readjustments of existing spaces. Furthermore, it is a tool to analyze the impact of new constructions of surrounding buildings or even for studies of boundary height parameters of buildings around these sites.