近70年中国黄土高原气候生产力演变分析

Evolvement of climate-productivity over China Loess Plateau

利用黄土高原地区68 a气象资料,采用EOF、REOF、CEOF分解和小波分析等方法,研究了该区域气候生产力时空演变特征,结果表明:黄土高原气候生产力呈递减趋势;20世纪30-40年代高,60年代次高,90年代最低,80年代次低;1978-2000年、1951-1960年以下降为主,1978-2000年最为突出,1961-1978年曲线不断上升,2000年后呈现上升;气候生产力演变存在多种周期,其中4年周期最为明显;存在相关程度高的3个特征区域,即高原西部生产力不稳定低产区、南部相对稳定高产区、高原东部不稳定区;高原中北部是气候生产力变化的敏感区;气候生产力的空间振幅存在传播趋势,从高原中东部向东南传播。

By applying empirical orthogonal function （EOF）, rotated empirical orthogonal function （REOF）, complex empirical orthogonal function（CEOF） and wavelet analysis on 1961 - 2000 weather datum of China loess plateau and 1937-2004 datum of Xifeng station, the spatial and temporal variations of China loess plateau climate-productivity were investigated. The results showed that the climate-productivity kept decreased over China loess plateau. The highest climate-productivity was in 1930s to 1940s, the high was in 1960s. The lowest was in 1990s, the lower in 1980s. The climate-productivity obviously decreased during 1951- 1960 and 1978-2000, especially so in 1978-2000; the curve continuously went up during 1961-1978 and stayed growing after 2000. By using wavelet analysis, there were kinds of periods of climate evolvement, the 4 years period was more remarkable. Three divisions, the west, east and south part were identified, showing strong temporal variability. The west part of divisions was unsteady and low yield of climate-productivity, the south part was steady and high yield, the east part was astatic. The sensitivity of the climate-productivity variation was in the north-central plateau. The variation information of the climate-productivity flowed from the east-center area to east south of the plateau.