Chinese Acad Sci;
Inst Mt Disaster & Environm;
Chengdu 610041;
Peoples R China;
Chinese Acad Sci;
Cold & Arid Reg Environm & Engn Res Inst;
Lanzhou 730000;
Peoples R China;
the; source; regions; of; Yangtze; and; Yellow; Rivers; the; stress; within; grassland; ecosystems; inverted; 'U'; model; driver;