1. sampling survey method: this method is to sample the river water, collect the sampled materials, and analyze the samples to determine the concentration of pollutants.
2. Remote sensing technology: Remote sensing is a technology that uses sensors on satellites or aviation platforms to obtain information on the earth's surface. Through remote sensing technology, we can obtain images of rivers and other relevant data, such as changes in suspended matter and color, so as to calculate the scope and area of river pollution.
3. Mathematical model: Modeling according to the characteristics of river flow, the distribution of pollution sources and the transmission parameters of pollutants. And use the mathematical model to calculate the scope and area of river pollution diffusion.