厄尔尼诺对宁夏干旱山区农作物的影响初探

A preliminary study on impact of El Nino on crops in arid mountainous areas of Ningxia

引起赤道太平洋海温异常的厄尔尼诺现象,通过大气环流的异常影响东亚季风系统,对宁夏气温、降水等农作物赖以生存的环境造成影响。为了解厄尔尼诺对宁夏中南部山区气候要素的变化及对产量的影响程度,本文采用动态距平分析法,分析了宁夏干旱山区1961年以来厄尔尼诺发生当年和次年气候要素、农业气候资源及小麦、玉米和马铃薯的产量变化。结果表明,厄尔尼诺造成宁夏暖冬,有利于设施农业生产。厄尔尼诺使冬、春季气温偏高,但夏季气温明显偏低,作物生长季积温减少,高海拔地区热量强度更加不足,影响玉米成熟。厄尔尼诺发生次年,中部干旱带春季降水偏多,有利于保障春播和作物苗期生长,但夏、秋季降水偏少,容易出现干旱,不利于作物生长发育。南部山区春季、秋季降水偏多,有利于作物播种和苗期生长,但夏季降水偏少,特别是作物开花、灌浆初期降水偏少,不利于玉米、马铃薯生长。玉米灌浆中后期、马龄薯成熟期降水偏多,容易引起马铃薯晚疫病。厄尔尼诺发生当年小麦、玉米和马铃薯减产;厄尔尼诺发生次年,山区冬小麦、玉米和马铃薯平均增产幅度分别为8.9%、7.8%和8.4%,均为显著增产。

El Nino,cause the anomaly equatorial Pacific sea surface temperature,impacts Ningxia temperature,precipitation and other elements which crops survival environment in the East Asian monsoon system through abnormal atmospheric circulation. In order to understand the effect of El Nio on change of climatic elements and yield in central and southern mountainous regions of Ningxia,the current study analyzed,by dynamic difference method,the climatic factors,agro-climatic resources,El Ni1 o yearly occurrence,as well as the yield changes of wheat,maize and potato. The results showed that,El Nino causes a warm winter in Ningxia which facilities greenhouse agricultural production. El Nino makes warm winter and spring,but lowers temperature than normal in the summer significantly. It decreased thermal accumulation in crops during growing season,especially heat intensity highly insufficient in high altitude regions where maize cannot mature. In the following year of El Nino occurrence,the rainfall in spring increased in the central dry zone,which helps sowing and crop seedling growth,but decreased in summer and autumn which prone to drought. In southern mountainous region,El Nino caused more rainfall in the spring and autumn,but less in the summer,likely to cause drought in corn crucial growing stage. In the late filling and maturity,more precipitation may cause potato late blight and interrupt harvest. When El Nino occurs,the yields of winter wheat,corn and potato are decreased,but the yields of three crops are increased significantly in the following year in central and southern mountainous regions.