Conclusion

Planned urbanisation through policy interventions is quintessential for the sustenance of natural resources and also people’s livelihood. This entails holistic approaches in urban development while preserving the areas of ecological and environmental significance to ensure the inter-generational equity. Land use changes due to unplanned urbanization have led to a severe decline in open spaces leading to imbalances with the scarcity of natural resources (water, etc.). Urban analyses at microscales highlight the role of agents such as IT revolution, industrialization, commercial activities in urbanization and the loss of vegetation cover. BSR has lost major vegetation and open spaces and resulted in 86.35 % of the built-up area by 2017. PIE has 87.39 % region covered with the built-up area and only 2.11% under vegetation. WF has transformed from village-based ecosystem to highly polluted urban pocket within four decades as covering 81.61% built-up area. These regions highlight the extent of mismanagement of open spaces (vegetation cover, water bodies, etc.) in the city. Though the unplanned developmental activities in these region have provided direct-indirect employment and business opportunities, but resulted in degradation of the biophysical environment, affecting the health of citizen and also a scarcity of natural resources. Spatial patterns of urbanization in three regions through landscape metrics shows least NP values representing single class dominance. ROS depicts least ratios of open space with the more convoluted shape as compared to 1973 due to progression in built-up cover. The results highlight the necessity of effective planning and restriction on further exploitation of other land use features for human well-being. There is an urgent need to mitigate the impacts through integrated planning strategies and policies. Modelling and visualization reveal built-up area likely to cover 92.12% of PIE region at the cost of open areas and vegetation as compared to other. The rampant urbanisation due to accelerated economic performance in three micro gradients is signified vast LU transition through stressing the environment, degrading vital natural resources. Modelling LULC change has provided an accurate, spatially detailed and consistent urban mapping capabilities over a temporal scale, which enables decision makers to evolve appropriate land use strategies with conservation measures to protect the vital ecosystems from further degradations.

Acknowledgment

We are grateful to (i) APN Network for climate change [ARCP2012-FP03- Sellers] for the financial support to carryout research – Mega Regional Development and Environmental change in India and China, and (ii) the NRDMS Division, The Ministry of Science and Technology, Government of India; (iii) Indian Institute of Science and (iv) Indian Institute of Technology, Kharagpur for the infrastructure support. We thank (i) United States Geological Survey and (ii) National Remote Sensing Centre (NRSC-Hyderabad) for providing temporal remote sensing data.