The grey system assessment method, air pollution integrated index are applied to evaluate the atmosphere, surface water, noise environmental quality of valley cities in western China.
A grey miasma, neither cloud nor mist low in the sky and the atmosphere was stifling.
一些似云非云，似雾非雾的灰气低低的浮在空中，使人觉得憋气。
3
Improve the season tendency model by using the grey system modern and predicate the future yearly figure of the dioxide of the atmosphere about the system environment.