Review of environmental impact assessment applications in New Delhi's urban development: A systematic PRISMA review

Environmental impact assessment (EIA) is a legal mechanism for assessing and minimizing the environmental impacts of urban development projects in India. New Delhi, as India's capital city, offers a critical empirical context for evaluating EIA practice, given its rapid urbanization, ecological vulnerability, and political importance. The scope of this systematic review is to explore the application of EIA to urban development projects in New Delhi between 2000 and mid-2025. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the initial search yielded 317 records, and 28 documents (peer-reviewed articles, theses, official EIA reports, and government action plans) were included after screening and assessing their eligibility for qualitative synthesis. Key sectors were transportation infrastructure (Delhi Metro extensions), riverfront and floodplain projects on the Yamuna, water and sewage infrastructure, and solid waste/landfill projects. The review found that EIA in Delhi did include project design improvements where mitigation was introduced, such as noise barriers, compensatory plantation, dust control; however, EIA also suffers from systematic shortcomings: No cumulative or strategic assessments, insufficient baseline ecological and hydrological data, inadequate public participation, and poor monitoring and enforcement after clearance. The evidence does indicate that while Delhi's high-profile projects (Delhi Metro) incorporated environmental safeguards, the long-term outcomes (Yamuna water quality) have been unsatisfactory. The article concludes with recommendations to strengthen institutional monitoring, adopt cumulative and strategic environmental assessments, enhance transparency, and integrate advanced technologies (geographic information system [GIS], remote sensing) for baseline and follow-up studies.