To analyze urban sprawl using remote sensing : a case study of London, Ontario, Canada

Abstract

Urban growth is one type of urban development. Many Canadian cities have dramatically evolved over the past twenty years. Along with the rapid growth of urban region, urban sprawl has become one of the most significant issues challenging most cities. Remote sensing techniques are frequently used to analyse urban growth and sprawl. In this study, three temporal satellite images, which were taken at 1990, 2000, 2010 respectively, are classified using software ENVI to determine the urban extent and growth pattern of the city of London, Ontario, Canada. Statistical models including Shannon‘s entropy and Pearson‘s chi-square are applied to calculate the degree of sprawl and degree of freedom of London. Moreover, the overall degree of goodness of the urban growth is calculated as a promotion of the former two statistic models towards the analysis of urban growth. The results shows London is sprawled in the past 20 years (from 1990 to 2010) with a decreasing degree of freedom and a moderate degree of goodness of urban growth. Apart from mathematical analysis, policies that have been implemented since 1990s to curb urban sprawl in London are reviewed. Key factors that impact the urban growth pattern of London are identified through reviewing. It is found that 1993‘s annexation, the creation of Urban Growth Boundary and changed political intentions are the main factors. By analyze these factors, it also help to explain the results derived from mathematical models. Brownfield redevelopment, residential intensification, smart moves are regarded as the most important strategies to deal with urban sprawl carried out by London‘s local government. It also witnesses a great impact of policies initiated by the province on a mid-sized municipality such as London. It is argued that municipalities gain only limited political autonomy and administrative capacity. Recommendations are addressed specifically for the related strategies for further promotions.