The study focused on finding out where pollution in the Jinghe River in China comes from, especially the types of pollutants during dry and wet seasons. The researchers used a computer model and analysis methods to figure out if the pollution comes from specific sources like sewage or rainfall runoff. They discovered that ammonia pollution mainly comes from things like sewage all year round, while nitrate pollution is linked to sewage during dry times and rainfall runoff in wet periods. This means that different types of pollution sources affect the river's water quality at different times of the year.