Briefly describe the main methods of environmental prediction.

Environmental prediction is to estimate and speculate the future development trend of the environment based on information and monitoring data, and to provide a basis for putting forward countermeasures to prevent the environment from further deterioration and improve the environment.

The procedure of forecasting work can be roughly divided into four stages and eleven steps:

1. Preparation stage

2. The stage of collecting and analyzing information

3. Forecast and analysis stage

4. Eleven steps to output forecast results: determining forecast purpose, determining forecast time, making forecast plan, collecting forecast data, analyzing test data, selecting forecast method, establishing forecast model, carrying out forecast calculation, checking forecast results, outputting forecast results and submitting forecast results.

(1) According to the characteristics of forecasting methods, qualitative forecasting methods include: expert evaluation method, illegal method, subjective probability method, set opinion method, analytic hierarchy process, leading index forecasting method, etc. Quantitative forecasting methods include: trend extrapolation method, regression analysis method, input-output method, fuzzy reasoning method, Markov method and so on. Comprehensive forecasting method

(2) Classify 1 according to the principle of forecasting methods. Intuitive method: namely qualitative prediction method II. Causality prediction method: the relationship between the predicted object and related factors is analyzed by using the correlation principle, and a model is built based on this relationship to predict.