Urban expansion quantification from remote sensing data for sustainable land-use planning in Mangaluru, India

Abstract

Urban growth is indispensable in developing countries, particularly in the context of rapid economic development and growing urban population. The idea of managing urban growth is often restricted exclusively to large metropolis; ignoring small and emerging cities from the requirement of having sustainable urban growth strategies. India, experiencing a rapid pace of urban growth is expected to host its future urban population in its small and medium-sized cities. In this context, the dynamics of urban growth in numerous small and medium-sized cities must be studied and urban policies must be reoriented to ensure sustainable urbanisation in future. However, the nonavailability of geospatial data for generating information database and models to support decision making processes on a local scale pose challenges in developing countries. The remote sensing technology offers cost-effective, timely, and efficient technology to collect urban spatial data, to generate urban physical and socioeconomic information using various GIS and statistical models. In this study, the spatial pattern, dynamics and goodness of urban growth in Mangaluru city were studied in the context of its implications for future sustainable development using the techniques of remote sensing, GIS and statistical models. The urban land is delineated from the Landsat series of satellites then, the statistical models were applied to study the trend of urban growth. The built-up land in Mangaluru has increased significantly by more than 400 % during 1972–2018. Further, subtleties of urban growth were studied by extracting land-use expansion modes, UEI Index, UED Index, Pearson's Chi-square and Shannon's entropy. Finally, the goodness of urban growth was measured to identify the sustainability of urban growth. The findings suggest that the urban expansion mode was dominated by leapfrogging and edge expansion at the peri-urban area during initial periods which eventually gave way to infilling and edge-expansion. Also, a rapid expansion in urban land was expected in the southern and south-eastern part of the city. The study confirms the prevalence of the highly unsustainable nature of urban growth in the study area and therefore advocates participatory urban planning in managing and for achieving a sustainable urban growth.