农业气候资源多时间尺度分析——以郑州市小麦玉米为例

小波分析的时域局部变化特征可展现气候序列的精细结构,能够揭示不同时间尺度气候序列所隐含的不同变化规律,是进行时域分析的有力工具。论文以郑州市小麦、玉米生育期间的光热水农业气候资源分析为例,用Morlet小波变换法对其进行多时间尺度变化特征及演变规律分析。结果表明:郑州小麦、玉米生育期间的光热水气候要素具有不同的年际及年代际时间尺度周期变化规律和转换特征;小波变换能很好地揭示农业气候资源变化所包含的周期分量;其气候变化特征与全球气候变化趋势相比,有其一致性,也有其局地特殊性。

Multiple Time Scales Analysis on Agroclimate Resources--Taking Wheat and Maize in Zhengzhou City as a Example

The agroclimatic resources possess multple time scales features in time field apart from the apparent spatial variation characteristics,and the large time scales include the small ones.The different time scales conceal different variational rules,such as drought,flood,coldness and warmness etc.The wavelet analysis is a powerful tool because its local variational characte-ristics in time field can reveal the fine structure and the diverse rules containing in different time scales of climate series.Thus,the wavelet analysis method offers a new approach for analyzing the time scale structures and changing mechanism of agroclimatic resources.As an example,the multiple time scales characteristics and variational rules of agroclimatic resources for wheat and maize growth phases in Zhengzhou city were analyzed by means of Morlet wavelet transformation.The results showed that 1)the multiple time scales rules and changing charac-teristics of sunshine,temperature and precipitation series were different on interannual and interdecadal basis.The time variance of precipitation spectrum is the strongest and the most changeful,the temperature spectrum is next and the sunshine spectrum is the last.It is coincident with the fact that the variation of precipitation data is more intense than the ones of temperature and sunshine data.2)A concise and compact information of periodic components of the measurements in the scale-time domain was revealed by wavelet analysis.The results can be proved by other analysis schemes,such as power spectrum,trend analysis,M-K check,etc.3)A clear decreasing trend can be found in the sunshine series over wheat and maize growth period,but the temperature trend is inverse and no obvious trend in precipitation series.Comparing with the trend of global climate change,the consistent and the special local features of climate change existed in Zhengzhou city.