Spatial distribution and source analysis of SO2 concentration in Urumqi

• Exact latitudes and longitudes, altitudes, heights and diameters of point sources are collected by Google earth.
• Simulating the SO2 spatial distribution by CALPUFF.
• CALPOST trace back the contribution of every point source.
• Monitoring stations can't reflect the spatial distribution of SO2 concentration roundly in Urumqi.

This paper applies CALPUFF model to simulate the spatial distribution of sulfur dioxide in Urumqi and analyzes the source contribution to areas where the SO2 concentration is high. The result shows that annual mean concentration is highest in the middle of Saybagh and with the value of 44 μg/m3. The maximum 24-h averaged SO2 concentration is highest in the junction area of the middle-west of Saybagh and the north of Urumqi county, and the highest value is 467 μg/m3. The spatial distribution of SO2 in January is similar to that in October, and April is similar to that in July. National monitoring stations are dense in the middle of city where the concentration is low and can't reflect the spatial distribution effectively. Baosteel group contributes most to the Saybagh high concentration area (37 μg/m3/a); China National Petroleum Corporation Urumqi petrochemical company contributes most to the Midong high concentration area (5.3 μg/m3/a); Houxia power plant contributes most to the Houxia high concentration area (33 μg/m3/a).