A Study of Patna Municipal Corporation Assessment of the Dynamics of Urbanization

A Study of Patna Municipal Corporation Assessment of the Dynamics of Urbanization Vishal Kumar* 1. Introduction : Urbanization is a primary driver of changing flood risk in Patna. The rapid conversion of agricultural land, wetlands, ponds, and open spaces into built-up surfaces increases surface runoff, reduces infiltration and storage, and places a growing number of people and economic assets in locations that are physically exposed to flooding. This paper quantifies the spatio-temporal dynamics of urbanization within and around the Patna Municipal Corporation using multi-temporal satellite data, census and projected population statistics, and landscape metrics such as Shannon’s entropy. The analysis spans the period from approximately 1990/2001 to 2025, with forward projections to 2035 where published estimates are available. Emphasis is placed on the absolute and relative growth of built-up area, the accompanying decline in permeable land covers, the directional pattern of urban sprawl, and the measurable impact of these changes on surface runoff generation. 2. Data and Methods : Land-use/land-cover (LULC) change detection was performed on multi-temporal Landsat and Sentinel-2 imagery using supervised classification techniques. Built-up area extraction additionally employed Normalized Difference Built-up Index (NDBI) variants and SAR-based speckle-divergence methods, which have been shown to provide complementary accuracy in the Patna urban agglomeration. Population figures were compiled from the Census of India (1991, 2001, 2011) and subsequent official and scholarly projections. Shannon’s entropy and directional sector analysis were used to characterize the evolution of urban form from compact to more dispersed configurations. Curve-number based runoff modelling provided a quantitative link between LULC change and hydrological response. 3. Population Growth Dynamics : Patna has experienced continuous and substantial demographic expansion. The population of the urban agglomeration rose from roughly 0.49 million in 1951 to approximately 1.70–2.05 million by the 2011 Census. More recent estimates place the 2025 population of the broader urban agglomeration in the range 2.69–2.99 million. Within the municipal limits, residential densities are already high; consequently a large share of incremental growth is occurring in peri-urban tehsils and census towns such as Danapur, Phulwari Sharif, and Masaurhi. Migration from rural Bihar and the concentration of administrative, educational, and commercial functions in the capital further reinforce this outward pressure. *Department of Geography, Central University of South Bihar, Gaya, India, Email: [email protected]