With the grey treatment of rudimentary data during certain period, the key factors were indicated.

In this paper, the present sifuation and causalagency of the water pollution of the Dongping lake are analyzed, and the key factors of water pollution are found.

Five key factors affecting insect survival and development were determined: rice stem flour, wheat germ, yeast and rice chaff flour had an effect on the survival rate of larvae, sucrose and wheat germ affected the length of the larval stage, rice stem flour also worked on the pupal weight.

A method for selecting key factors in environmental impact assessment;

Research into the effects of the middle route of China s south-to-north water transfer project on water bloom in the middle-down stream of Hanjiang River and the countermeasures Part Ⅰ:An analysis of the key factors generating water bloom in Hanj;

Original air monitoring data of Tangshan was analyzed with grey systematic principle, and key factors and pollution tendency were evaluated, based on which air quality of year 2005 and 2010 was predicted.

Monitoring and analysis of phytoplankton and the key water quality parameters in the Four Pearl River Openings and the nearby beach waters, PR China;

Phytoplankton ecology and the analysis with key water quality parameters in the Pearl River Estuary;

Phytoplankton and the key water quality parameters (dissolved oxygen(DO),phosphors(PO 3- 4-P),nitrate(NO 3- 4-N)) were investigated and summarized fronm macroscopic and specific points in the offshore waters in the four Pearl River Opening(Humen, Jiaomen, Hongqili,Hengmen)and the nearby beach waters.