A New Index for Measuring Urban Ecological-Environmental Spatial Inequality

In recent years, the quality of the urban environment has received more attention in a variety of disciplines such as planning, geography, sociology, health sciences, and many others. In this paper, a new approach is proposed to measure urban environmental spatial inequality based on the geographical distribution of green spaces and the theory of urban political ecology. In this approach, ecological spatial inequality will be defined, modeled, and measured through green spaces extracted from satellite remote sensing observations. Urban political ecology provides a theoretical framework for implementing green spaces extracted from satellite images as a proxy for modeling the built environment conditions in urban areas. A greenness map, represented by the Normalized Difference Vegetation Index (NDVI), illustrates the highly uneven spatial distribution of green spaces, e.g., private, semi-public, and public. The proposed approach has been applied to study and map the urban ecological-environmental spatial inequality in Tehran, the capital city of Iran, and one of the fastest-growing cities in the world. The results show that most parts of the city and the majority of the population are suffering from spatial inequality in terms of Ecological-Environmental conditions. This new index has high potential to be applied in other cities with a similar socio-ecological context and spatial settings.