South China Flood Season Climate Anomalies Characteristics And Impact Factor Analysis

By use of the monthly mean precipitation and temperature data at 160 stations in China during 1951-2000.Investigation of precipitation and temperature anomalies and corresponding general circulation has been performed. In the study of the mechanism of precipitation anomalies, the discovery is then chiefly to study the effect of SSTA on precipitation and temperature in pre-floods period in South of China, concluding that there is a high con-elation between season precipitation in South of China and SSTA SSTA distribution. Some conclusions in this paper as followed:(1) The distribution of precipitation in the South of China is asymmetrical. The most rainfall in the pre-flood period and annual are both happen in the east of South of China . The least rainfall in the pre-flood period and annual are both happen in the north of South of China ;(2) The total rainfall tendency has little change ,while the total temperature tendency is increase.(3) The precipitation anomaly existed 3year. 5year 7year 14year periodic variation in the pre-flood period in the South of China. The temperature anomaly existed 2year 4year 5year12year 19year periodic variation in the pre-flood period in the South of China.(4) The precipitation in the pre-flood period in the South of China is the same to that of the Neimeng and the southeast of China, while it is opposed to that of the north area of Changjiang ;The temperature in the pre-flood period of South of China is opposed to that of most areas of China.(5)There are some relationship between the precipitation and temperature in the pre-flood period in the South of China. The precipitation and temperature both existed 5year periodic variation in the pre-flood period in the South of China. The precipitation and temperature in the pre-flood period in the South of China is the same to that of the Neimeng and the southeast of China. There are some relationship between more (less) precipitation years and colder(warmer) years. The Southern Asia High and the Subtropical High of the more precipitation years and colder years are both more weak; The Southern Asia High and the Subtropical High of the more precipitation years and colder years are both more strong.(6)There is apparent negative correlation between pre-floods period precipitation in South of China and SSTA(5-8 monthly averaged in former year), especially the higher correlation in the "KEY regions" (130°~158°E, 5°~18°N) ;There is apparent positive correlation between pre-floods period temperature in South of China and SSTA(10-11 monthly averaged in former year), especially the higher correlation in the "KEY regions" (85°~97°E, 5°~16°N) .