Abstract
An airshed concept has been widely practiced in developed countries as a tool for air quality mitigation, but its application in developing countries is still evolving. The air pollution challenges in developing countries are complex and cannot be solved merely through a city-centric approach, requiring a suitable framework for regional airshed approach to better comprehend the sources, impacts and design adequate response, rather than localised action within administrative boundaries of a city. The implementation of the airshed approach in developing countries may encounter challenges due to various constraints, including limited resources, specifically in terms of finance, and a shortage of trained researchers, such as modellers. Additionally, the lack of high-performance computational facilities and institutional networking further adds to the difficulties faced by these countries. Thus, the main objective of this review paper is to critically analyse the various airshed approaches that are commonly used in the developed countries. By doing so, the review identify gaps in air pollution mitigation strategies specifically in developing countries and proposes a cost-effective and practical airshed management framework that can be implemented in developing countries. Airshed delineation should be based on scientific assessment of air pollution transport and accumulation through representative stations in an airshed and robust source apportionment combining meteorological factors. The domain falling in the spatial extent of airshed may be classified as nonattainment areas for maintaining the uniformity in control actions and effective implementation. Building on city-specific airshed framework, an institutional framework for regional airshed management has also been suggested for planning, monitoring and implementing the participatory approach with financial autonomy and extant regulatory backup. The suggested framework can useful for the policy makers to analyse the air pollution mitigation strategies on a regional scale.