Indices based assessment of built-up density and urban expansion of fast growing Surat city using multi-temporal Landsat data sets

The population growth in urban areas leads to the expansion of built-up area which leads to a number of serious problems like environmental pollution, destruction of urban ecology, climatic modification etc. In this study, we have tried to assess the linkages and association between population growth and built-up expansion in Surat city. Landsat satellite data (TM, ETM+ and OLI/TIRS) has been used for 1991, 2001, 2011 and 2019 to extract the built-up area while the demographic data of the city was obtained from the Census of India and SMC. The built-up area has been extracted using index based built-up index (IBI) method. The association between urban expansion rate (RUE) and population growth rate (PGR), distribution of population and built-up area and the population and built-up density was analyzed using linear regression technique. The result shows that both the population and built-up area of Surat has increased rapidly but the rate of increase of built-up area is higher than the population. The statistical analysis shows that the density of population and built-up area have very strong-positive relationship while their distribution have moderate-positive relationship. On the other hand the PGR and RUE shows positive but weak relationship. The main finding of the study is that the growth rate of population and urban area are not identical to each other but their distribution and density have strong relationships with each other. The association between PGR and RUE is not always significant because of the variation in their rate.

Automated summary

The study shows that the population and built-up area of Surat are increasing rapidly, with the built-up area growing at a faster rate than the population. There is a very strong positive correlation between population density and built-up area, and a moderate positive correlation between population distribution and built-up area. Therefore, while the growth rates of population and urban area may not be identical, there are strong relationships between their distribution and density.