7Folland C K,Karl T R,Christy J R,et al.Climate Change 2001:The Scientific Basis (eds Houghton T,et al).Cambridge:Cambridge Univiversity Press,2001.99~181.
8IPCC.Climate Change 2001:Impacts,Adaptation & Vulnerability.Cambridge:Cambridge University Press,2001.1~18.
9Bradley R S,Diaz H F,Eischeid J K,et al.Precipitation fluctuations over northern hemisphere land areas since the mid-19th century.Science,1987,237:171 ~ 175.
10Hulme M.A 1951-80 global land precipitation climatology for the evaluation of general circulation models.Climate Dyn.,1992,7:57~721.