Analysis of urban decay from low resolution satellite remote sensing data: Example from organic city in Nigeria

Abstract

Urban decay reflects deleterious manifestation of urban environment neglect occasioned by poverty and low capacities of dwellers to effect meaningful repairs of aging housing stock. Though urban decay has social, economic and cultural dimensions, it is primarily a physical entity and can be observed comparatively across districts and cities. This paper analyzed the spatial and temporal pattern of urban decay in different parts of a traditional organic city through data extracted from satellite remote sensing images. It analyzed temporal differences in urban quality in the city using uniform parameter of urban blight measurement. It presented a classification scheme for mapping urban decay from remote sensing data using composite parameters including urban densities, urban accessibility, age and type of building materials and vegetation/impervious surface components. These indices were measured from remote sensing data and condensed into an urban decay index through geostatistical analysis of extracted data layers of data. The average indices of each of the parameters were condensed into the city blight index for the entire city. The computed City Blight Index was 0.39 in 1975, 0.38 in 1995 and 0.48 in 2005. The paper discussed the factors responsible for the temporal changes in urban blight condition in Ibadan city