Zhang Q,Xu C Y,Zhang Z X.Observed changes of drought/wetness episodes in the Pearl Riverbasin,China,using the standardized precipitation index and aridity index[J].Theoretical and Applied Clmiatology,2009,98:89-99.
[4]
Silva Y,Takahash i K,Chvez R.Dry and wetrainy seasons in the Mantaro River bas in(central Peruvian Andes)[J].Advances in Geosciences,2007,14:1-4.
[5]
Smis A P,Niyogi D D S,Raman S.Adopting droughtindices forest miating soil moisture:a North Carolin a casestudy[J].Geophysical Research Letters.,2002,29(8):1183-1186.
[6]
Moreira E E,Paulo A A,Pereira L S,et al.Analysis of SPI drought classtransitions using loglinear models[J].Journal of Hydrology,2006,331:349？359.
MihajlovicD.Monitoring the 2003-2004 meteorological drought over Pannonian part of Croatia[J].International Journal of Clmiatology,2006,26(15):2213-2225.
[9]
Livada ,I Assimakopoulos V D.Spatial and temporal analysis of drought in Greece using the Standardized Precipitation Index(SPI)[J].Theoretical and Applied Clmiatology,2007,89(3-4):143-153
Edwards D C,McKee T B.Characteristics of 20th Century Droughtin the United Statesat Multiple Time Scales[D].USA:Department of Amtos pheric Science,Colorado State University,1997:18-21.
[12]
Patel N R,Chopra P,Dadhwal V K.Analyzing spatial patterns of meteorological drought using standardized precipitation index[J].Meteorological Applications,2007,14:329-336.
[13]
Mckee T B,Doesken N J,Kleist J.The relation ship of drought frequency and duration to tmie scales[R].California:Eighth Conference on Applied Clmiatology,1993.
