Longxing, nestled within Shanxi Province, China, occupies a geographically complex position at coordinates 35.6091°N, 111.2304°E. The city’s terrain is characterised by the foothills of the Taihang Mountains, contributing to a varied topography of valleys and plateaus. This elevation, averaging around 1,400 meters, influences local wind patterns and temperature inversions, critical factors in air quality. Longxing isn’t directly adjacent to major bodies of water, but relies on regional river systems fed by mountain runoff. The surrounding landscape is a mosaic of agricultural land – primarily wheat and maize – and increasingly, industrial zones associated with Shanxi’s coal mining and processing industries. This proximity to heavy industry is a significant determinant of air pollution. The urban-rural gradient is relatively sharp; the city centre is densely populated, while the periphery quickly transitions to agricultural fields and forested slopes. This creates localized pollution hotspots within the city, exacerbated by limited dispersal due to the surrounding terrain. The prevailing winds, often originating from the northwest, can carry pollutants from larger industrial centres further east, impacting Longxing’s air quality. The city’s location within a basin-like structure can also trap pollutants, particularly during stable atmospheric conditions. Understanding this interplay of geography and industry is crucial for addressing Longxing’s air quality challenges.

Longxing experiences a distinct continental monsoon climate, heavily influencing its air quality throughout the year. Spring (March-May) sees increasing agricultural activity and dust storms originating from the Gobi Desert, elevating particulate matter. Temperatures begin to rise, but stable atmospheric conditions can trap pollutants. Summer (June-August) brings the monsoon season, offering periods of cleaner air due to rainfall washing away pollutants and increased wind speeds. However, humidity can also contribute to secondary pollutant formation. Autumn (September-November) is often the most challenging period. Reduced rainfall, coupled with increased heating demand and industrial activity preparing for winter, leads to a build-up of coal-related pollutants. Temperature inversions become frequent, trapping pollutants near the ground. Winter (December-February) is characterised by cold, dry conditions and heavy reliance on coal for heating. This results in consistently poor air quality, with smog and haze prevalent. Sensitive groups – children, the elderly, and those with respiratory conditions – should limit outdoor activity during autumn and winter. Spring can also pose risks due to dust. Favour summer months for outdoor activities, but monitor conditions. Local meteorological forecasts are vital for informed decision-making.