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This image shows prevailing wind patterns during Kunming’s rainy season which runs roughly from May to October. Strong southwesterly winds bring monsoons from the Bay of Bengal over the Burmese landmass into Yunnan province.
The red rectangle in the southwest corner is the site of the PetroChina oil refinery, the focus of a series of recent environmental protests by concerned Kunming residents. GoogleMaps has detailed imagery of construction site’s layout. The purple area to the north is Kunming’s city center, determined by the area inside of Kunming’s 2nd ring road and home to a population of approximately 2.5mn.
Winds passing over the 10 million ton PetroChina oil refinery will send toxic pollutants directly over Anning city and Kunming’s most populated urban districts. Anning is Kunming’s largest satellite city with an urban population of 100,000. Kunmingers often drive to Anning to soak in its famous hot springs (also predictably in the pollution path), but in the last 10 years, most of Kunming’s heavy industry moved to Anning in an attempt to reduce pollution in the Dianchi Lake watershed.
After passing over Anning, winds become more concentrated and pick up speed to shoot through three passes in the Xishan (Western Hills) mountain range. The solid line represents the most voluminous wind channel. It doesn’t take an expert to see that the oil refinery site was chosen at the most optimal point for dumping pollution onto Kunming. Perhaps this is why city officials are reluctant to release data from the project’s legally mandated environmental impact assessment.
To make matters worse, a strong southerly lake effect wind, constrained by Kunming’s eastern hills, pushes all westerly winds northward into the city center as they break over Xishan mountain range. This guarantees that nearly all winds that pass over the oil refinery site through Kunming’s downtown and finally into the city’s north district, home of an additional 1.5mn residents. Kunming’s north district, currently undergoing a major urban facelift, is planned as one of the city’s new core urban centers with a projected population of 3 to 4 million residents by 2020.