Assessment of PM2.5, PM10, SO2 and NO2 in the Northwestern Indian Himalaya—A Correlation with Tourism and Meteorological Parameters: Regional Collaborative Governance

Abstract

The influx of tourists to fragile mountain ecosystems like the Himalaya can exacerbate particulate matter pollution, as increased vehicular emissions, biomass combustion, and infrastructure development contribute to increased concentrations of PM_2.5 and PM₁₀. The present study attempts to analyse the impact of tourism activities on PM_2.5 and PM₁₀ at Mohal in the Kullu Valley during a span of 6 years (2016–2021). The daily highest concentration was found as 116.21 µg m⁻³ and 162.64 µg m⁻³ for PM_2.5 and PM₁₀, respectively. The particulate matter (PM_2.5 and PM₁₀) concentrations showed an increasing trend during whole study period. The day-to-day average concentration of PM_2.5 and PM₁₀ surpassed the NAAQS limits by 6% and 2%, respectively. In view of seasonal analysis, a higher concentration was found in winter than in autumn and summer, while monsoon season showed the lowest one values. HYSPLIT and CALIPSO highlight regional activities as the primary pollution source. The correlation analysis also showed the effects of meteorological parameters on the assemblage or cluster of air pollutants especially the effect of temperature on PM_2.5 concentration in winter and summer seasons. The annual exceedance factor was moderate in the area but a continuous increase was observed in the values. Karl Pearson’s Correlation analysis reveals the contribution of tourism activities increasing the load of PM_2.5, NO₂ and SO₂. Intending to better manage air quality in the Kullu valley and other Himalayan regions, the present attempt also aims to propose a new multi-scalar framework based on regional collaborative governance of PM_2.5 and PM₁₀ through web scraping techniques and browser extensions.