The researchers developed a model to allocate water pollutant emissions based on the capacity of the environment to handle them. They applied this model to 28 cities in Henan Province, China, and found varying reduction rates for pollutants like COD and NH3-N. The study showed that different types of sources, such as industries and urban areas, need to reduce their pollutant emissions by different amounts to improve water quality effectively. This approach helps connect total emission control with actual water quality improvement, addressing a long-standing issue in China. The findings can be used to enhance water quality in other regions facing similar challenges.