Socio-economic Analysis of Urban Sprawl Patterns and Air Pollution at the Urban Fringe in Developing Megacities: An Urban Ecosystems Valuation Analysis, with a Case Study of Delhi
By 2030, urban areas are projected to house 60% of people globally, and air pollution will be one of the leading causes of mortality. Urban sprawl typically refers to the wide-scale expansion of urban land use and the low density of urban populations. Despite the benefits of urban growth for the economy there are increasing negative environmental externalities being studied, such as urban air pollution due to increased infrastructure and road transport as well as biodiversity and vegetation loss. Although urban sprawl is a global concern, the challenges are in developing megacities facing greater socio-economic barriers with uncontrollable urban sprawl, impacting urban ecosystems at the rural-urban fringe.
This research study undertakes an assessment of the socio-economic impacts of urban air pollution and land use, with respect to urban and peri-urban agriculture and forestry (UPAF), in the growing climate of urban sprawl. It uses a case study analysis of peri-urban villages within Delhi and promotes methods to address sustainable land management practices, to reduce related socio-economic impacts (i.e. liveability, health and well-being as well as employment and industry).
Delhi is one of world’s most polluted and rapidly growing megacities and hence is a prime example of the impacts of urban sprawl and air pollution. This research undertakes a combined spatial data analysis, highlighting patterns of ambient pollution (NO2 and PM2.5) alongside land use change (as a measure of urban sprawl). Results show deprivations of agricultural and cultivatable land areas as well as crop yields alongside rising pollutant levels. Land value, social homogeneity and health are seen to be key externalities in response. Finally, a total economic value analysis of urban forestry within Delhi assesses the benefits of harnessing urban forestry as means of pollution mitigation and sustaining livelihoods at the fringe. A total economic value is given as Rs. 5,678,525.81 ha/yr (US$14,000 ha/yr). A closer look into the impact at the North-west border with Haryana is analysed at Narela, considering the recent urban expansion projects planned in Delhi by 2021, whilst understanding the ambitious national targets for reducing particulate air pollution by 20-30% by 2024. Finally, this study conveys the importance of emphasising transitional and sustainable land management to counteract the disadvantages of urban sprawl and foster a natural-based solution for pollution mitigation.