With rainfall data of 51 stations in April - September in the Pearl River basin during 1954 - 2003, we have applied the Principal Component Analysis method to research the spatial distribution characteristics of April...With rainfall data of 51 stations in April - September in the Pearl River basin during 1954 - 2003, we have applied the Principal Component Analysis method to research the spatial distribution characteristics of April - September rainfall. The results reveal the following. In the Pearl River basin, there is different precipitation varying from 600 mm to 1900 mm in April - September and precipitation decreases gradually from southeast to northwest. The standard deviation distribution decreases gradually from east to west on the whole. The rainfall distribution of the Pearl River basin has five main types： Type I： there is flood （drought） in the whole region, Type Ⅱ： there is flood （drought） in the north and drought （flood） in the south, Type IlI： there is flood （drought） in the east and drought （flood） in the west, Type IV： there id flood （drought） in the central part and drought （flood） in the east and west, and Type V： there is flood （drought） in center and drought （flood） in north and south. The types of the flood （drought） in the whole region and flood （drought） in the north and drought （flood） in the south appear much more than the others, being 64% of the total. From the 10-year moving average, it is seen that rainfall between April and September in the Pearl River basin region is mainly dry in 1983 - 1992, and mainly dry in the east and wet in the west in 1967 - 1971 and wet in the east and dryin the west in 1979.展开更多
Long-time series of high-resolution temperature record from Chinese Loess Plateau is rare. An April-September mean temperature reconstruction (1826-2004) has been developed for the north-central Shaanxi Province, Chin...Long-time series of high-resolution temperature record from Chinese Loess Plateau is rare. An April-September mean temperature reconstruction (1826-2004) has been developed for the north-central Shaanxi Province, China, based on tree-ring width analysis. The reconstruction captures 39.3% (p<0.001) of the variance in the instrumental data over the calibration period from 1951 to 2002. The reconstruction shows a high temperature period of 1928-1933, which coincides with the timing of the extreme drought event in 1920s in the entire northern China. The two low temperature periods in reconstruction are 1883-1888 and 1938-1942. With the global warming, the April-September mean temperature in study area has also increased since the 1970s, but has not exceeded the temperature in 1928-1933. Besides the statistical analysis, the reconstruction is also verified by the local dryness/wetness index and other dendroclimatological results.展开更多
基金Research on Techniques of Predicting the Prospects of Drought in Guangdong(2005B32601007)
文摘With rainfall data of 51 stations in April - September in the Pearl River basin during 1954 - 2003, we have applied the Principal Component Analysis method to research the spatial distribution characteristics of April - September rainfall. The results reveal the following. In the Pearl River basin, there is different precipitation varying from 600 mm to 1900 mm in April - September and precipitation decreases gradually from southeast to northwest. The standard deviation distribution decreases gradually from east to west on the whole. The rainfall distribution of the Pearl River basin has five main types： Type I： there is flood （drought） in the whole region, Type Ⅱ： there is flood （drought） in the north and drought （flood） in the south, Type IlI： there is flood （drought） in the east and drought （flood） in the west, Type IV： there id flood （drought） in the central part and drought （flood） in the east and west, and Type V： there is flood （drought） in center and drought （flood） in north and south. The types of the flood （drought） in the whole region and flood （drought） in the north and drought （flood） in the south appear much more than the others, being 64% of the total. From the 10-year moving average, it is seen that rainfall between April and September in the Pearl River basin region is mainly dry in 1983 - 1992, and mainly dry in the east and wet in the west in 1967 - 1971 and wet in the east and dryin the west in 1979.
基金the National Natural Science Foundation of China (Grant Nos. 40525004, 40701196 and 40599423)the Ministry of Science and Technology of China (Grant No. 2004CB720200)the foundation of the State Key Laboratory of Loess and Quaternary Geology (Grant Nos. SKLLQG0214, SKLLQG0516)
文摘Long-time series of high-resolution temperature record from Chinese Loess Plateau is rare. An April-September mean temperature reconstruction (1826-2004) has been developed for the north-central Shaanxi Province, China, based on tree-ring width analysis. The reconstruction captures 39.3% (p<0.001) of the variance in the instrumental data over the calibration period from 1951 to 2002. The reconstruction shows a high temperature period of 1928-1933, which coincides with the timing of the extreme drought event in 1920s in the entire northern China. The two low temperature periods in reconstruction are 1883-1888 and 1938-1942. With the global warming, the April-September mean temperature in study area has also increased since the 1970s, but has not exceeded the temperature in 1928-1933. Besides the statistical analysis, the reconstruction is also verified by the local dryness/wetness index and other dendroclimatological results.
