The Comparison Analysis of Flood and Drought Features Among the First Flood Period in South China,Meiyu Period in the Yangtze River and the Huaihe River Valleys and Rainy Season in North China in the Last 50 Years

摘要: Based on the Chinese 160 stations monthly precipitation supplied by National Meteorological Information Center of China,the distribution features floods and droughts events during first flood period in South Meiyu middle lower reaches Yangtze River Huaihe valleys rainy season North China are analyzed respectively compared with each other using droughtsfloods indices for 19512000.The interannual decadal variations three types rainfall also investigated DB-16 wavelet analysis method.The correlation is applied finding atmospheric circulation same term sea surface temperature(SST) preceding months which linked different kind rainfall.Results show: last 50 years,the frequency nearly as that droughts,and intensity greater than valleys,whereas has similar droughts,associated a drought tendency flooding valleys;the most remarkable annual variation,the second weakest,but variation just opposite;according to 500 hPa height field term,the close relationship low value systems at its north side while greatly influenced western Pacific subtropical high.The significant positive Okhotsk Blocking High mainly affected northwest side;the closely related SST Atlantic Pacific,while adjacent strongest influence tremendous near Bay Bengal.The emphasis this paper concentrated summary East Asia.The Asian summer very complex phenomenon important agriculture,industry people's life.This work attempts offer some references prediction monsoon rainfall.