辽京冀冬麦农业气候北界的研究

STUDIES ON THE NORTH AGROCLIMATIC BOUNDARIES OF WINTER WHEAT IN LIAONING, BEIJING AND HEBEI

本文提出了一个划分冬麦农业气候北界的数学模型,它包括:1.气候—冬麦越冬死亡率方程;2.空间—气候方程;3.将所研究地区划分网格,利用上述两组方程推算出每个网格的冬麦越冬死亡率,并根据死亡率的多少,通过电子计算机划出安全种植北界和可能种植北界。这个数学模型对农业气候区划的方法有一定参考意义。

A mathematical model about dividing the north agroclimatic boundaries of winter wheat in Liaoning, Beijing and Hebei has been set up in this paper.Spat-ial climatic equations were used to estimate temperature normals of any point in this region.The agroclimatic equation of death percentage of winter wheat was then applied to the point estimates of winter survival.Death percentages of each grid representing a square area (10×10km) on the topographic maps of 1: 1,000,000 scale were computed by the mentioned equations. AII these death percentages were then classified into three classes (<20%, 20-40% and>40%)by computer and printed out by LPT.The demarcation between the first class and the second one is called the safe planting boundary of winter wheat and the other demarcation is the potential planting boundary.The results indicated that the safe planting boundary is similar to the natural boundary in the 1950’s in the same area.In the potential planting region, winter wheat should take protective measure with great care so as to reduce the freeze damage.