宁夏山区小麦产量变化特征及其对气候变化的响应

Variations and responses of wheat yield to climatic change in the mountain area of Ningxia

利用宁夏山区各气象站1957～2002年的气候资料及同期小麦产量资料,分析了宁夏中部干旱带和南部山区小麦产量和气候要素的周期性变化特征以及小麦产量与气候要素的关系。采用常用的墨西哥帽小波(Mex-ican Hat)函数,分别对宁夏中部干旱带和南部山区小麦单产气候产量和气候要素时间序列进行了小波分析,分离、提取了小麦单产气象产量和气候要素时间序列的波动周期,并进行了相关性分析。结果表明:1954～2002年,宁夏中部干旱带小麦单产在波动中增长。气候产量与5月份降水量有明显的正相关。中部干旱带小麦气候产量具有4年左右、8年左右和16年左右的周期振荡,且以8年左右的周期最为显著。5月份降水量有4年左右、8年左右、16年左右和32年左右4个时间尺度的振荡周期,以8年左右、16年左右和32年左右的周期性振荡最强。气候产量和5月份降水量在4年和8年的振荡周期上有同位相,相关性达到显著水平。宁夏南部山区小麦单产在波动中稳步增长。气候产量与5月份降水量有明显的正相关,与5月份平均气温有明显的反相关。宁夏南部山区小麦气候产量有4年左右和8年左右的周期振荡,以4年左右的周期性振荡最强。5月份降水量有4年左右、8年左右、16年左右和32年左右4个时间尺度的振荡周期,以8年左右、16年左右和32年左右的周期性振荡最强;5月份平均气温存在着8年左右和16年左右2个时间尺度的振荡周期,以16年左右的周期性振荡最强。气候产量与5月份降水量4年和8年的振荡周期上具有明显的同位相,与5月份平均气温8年的振荡周期有明显反位相。气候变化对宁夏南部山区及宁夏中部干旱带小麦产量具有明显的影响。

Using Mexican Hat Wavelet, wheat climate yields and climatic factors in the middle arid region and in the south mountain region of Ningxia were analyzed. The wave periods of wheat climate yields and climatic factors were separated and picked up. Correlation of wheat climate yields with climatic factors was also analyzed. The results showed that, from 1954 to 2002, yield of wheat was increased with fluctuation in the middle arid region. There was a positive correlation between the climate yield and precipitation in May. Wheat climate yield had wave periods of about 4-year, about 8-year and about 16-year. The wave period of about 8-year was the most notable. Precipitation in May had 4 wave periods of about 4-year, about 8-year, about 16-year and about 32-year. Wave periods of about 8-year, about 16-year and about 32-year were more notable. The wheat climate yield had the same phase with precipitation in May in the 8-year period clearly. From 1957 to 2002, yield of wheat was increased with fluctuation in the south mountain region. There was a positive correlation between the climate yield and precipitation and a negative correlation between the climate yield and mean temperature in May. Wheat climate yield had wave periods of about 4-year and about 8-year. And the wave period of about 4-year was the most notable. Precipitation in May had 4 wave periods of about 4-year, about 8-year, about 16-year and about 32-year. The wave periods of about 8-year, about 16-year and about 32-year were more notable. Mean temperature in May had 2 wave periods of about 8-year and about 16-year. The wave period of about 16-year was the best notable. The wheat climate yield had the same phase with precipitation in May in 8- year period and 16-year period clearly, and had the adverse phase with mean temperature in May in 8-year period. The influence of climate change on wheat yield in the middle arid region and in the mountain region of Ningxia was obvious. Studying measures of answering climate change and scientifically adjusting planting structure of crops is one of the scientific problems to be urgently solved now and in the future.