Assessing the Effectiveness of Graded Response Action Plan (GRAP) in Managing Delhi’s Air Quality

Air pollution remains a persistent issue that affects our health and well-being. North Indian cities are particularly prone to poor air quality during the colder months. The Graded Response Action Plan (GRAP) was introduced as an air quality management policy in January 2017 to address Delhi's poor air quality during the colder months. It is a dynamic policy implemented based on the Air Quality Index (AQI), which progressively increases the severity of sanctions on various activities. However, the effectiveness of GRAP has not yet been evaluated rigorously. This study aims to fill this gap and propose necessary changes in analysing this policy for the post-COVID years of 2022–2025. The current analysis reveals that most improvements (when they occur) in AQI appear to be driven by meteorological variability rather than pollution management efficacy. It is found that all GRAP stages (1 to 4) were at best moderately effective in improving/managing AQI, with a < 40% success rate. At times, the implementation of GRAP worsened AQI, likely due to changes in atmospheric reactivity and/or long-range transport. The study revealed a lack of transparency in estimating and reporting key parameters (such as AQI) and details on actual on-the-ground implementation. GRAP’s uniform, reactive, and PM control-based measures fail to address localized AQ issues and secondary pollution. Additionally, the GRAP implementations are sometimes inconsistent, failing to adhere to the established AQI-based standards. Based on the outcome of this study, a comprehensive list of remedial measures is suggested to improve GRAP’s efficacy and effectiveness.