1. College of Resources and Environmental Sciences; China Agricultural Univ.; Beijing 100193 China
2. Research Centre for the Management of Agricultural and Environmental Risks (CEIGRAM) and Dep. of Crop Production; Technical Univ. of Madrid (UPM); Madrid 28040 Spain
3. The Univ. of Melbourne; Melbourne VIC 3010 Australia
4. Shenyang Meteorological Bureau; Shenyang Liaoning 110168 China