甘肃省玉米产量的主成分分析

THE PRINCIPAL COMPONENT ANALYSIS FOR CORN YIELD IN GANSU PROVINCE

应用自然正交函数方法将甘肃省玉米产量的趋势产量项（Ｙ＿ｔ）和气候产量项（Ｙ＿ｗ）进行展开，展开后的Ｙ＿ｔ、Ｙ＿ｗ第一特征向量都表明了Ｙ＿ｔ、Ｙ＿ｗ总趋势的一致性，其大值中心表明产量变率较大。通过对各主成分主要时间系数与各站Ｙ＿ｔ、Ｙ＿ｗ进行相关分布分析，筛选出全省玉米产量的八个站点，这些站点基本上代表了本省不同类型的农业气候区域的玉米产量水平和生育状况。

The tendency corn vield term(Y_t) and climatic corn yield term(Y_w)of Gansuprovince are expanded by n1eans of EOF. Their first characteristic vectors show thatgeneral tendency is consistent with the tendency yields of Gansu.The centers of largevalues is the large variabilities. By means of correlation analysis between Y_t timecoefficients and Y_t for each station,and the same method to Y_w, eight stations forpredicting corn yield are chosen,which represent basically yield levels and growingconditions under various kinds of agroclimatic regions of Gansu province.