Temporal Analysis of Climate Variability and PM2.5 Concentration Trends in Gaya city, Bihar: A 30-year Assessment (1990 – 2023)

Abstract

Climate change has a significant implication in urban environment especially on   public health, water resources, agriculture and ecosystems. The  predominantly affected areas are climate-sensitive regions like eastern India. The study examines changes in temperature, rainfall, PM2.5 (pollution pressure) and land use/land cover (LULC) over Gaya City, Bihar, during the period of 1990 - 2023. The result shows a constant increase in minimum, average and maximum temperature, leading to a narrowing of diurnal temperature.. Rainfall indicates high interannual variability with no clear long-term trend, indicating increased uncertainty in climate. PM2.5 exhibits an upward trend with short-term variation and recent partial falls. Regardless of intermittent improvement, annual mean concentrations remain constantly high from the standard values suggested by the national and WHO guidelines.. The LULC study reveals an extension of built-up areas,  increases in forest cover, and a decline in grassland and cropland, indicating the combined effect of afforestation and urbanisation. These interacting climate and anthropogenic changes are likely to intensify environmental stress, with implications for rainfed agriculture, urban heat island effects, and pollution levels. The study emphasizes the need for an integratedclimate adaptation, land management, and pollution control strategies at the district levels.