利用降水平均递增率求山地最大降水高度

BY USING THE AVERAGE VERTICAL VARIA- BILITY OF PRECIPITATION TO CALCULATE THE HEIGHT WITH MAXIMUM PRECIPITATION OF MOUNTAINS

本文引入降水平均递增率的概念,改进了文献中的计算方法,可以一次求出山地降水量与海拔的经验关系式中全部参数的最佳值,其中包括山地最大降水高度。并用实例说明了本法的步骤及特点。

Professor Fu Baopu analysed many data of precipitation about mountains in China and foreign countries, and suggested a famous experimental formula to express the relation between the precipitation P2 and the altitude z. It is usually as follows:where Ph-the precipitation at the foot of the hill, h-the height at thefoot of the hill, a and H (the height with the maximum precipitation of the mountain) are two parameters decided by regions and seasons. The original method to calculate these two parameters from observatioa data of mountains is a gradual approach method which searches the better solution, step by step and by eyes only.We shall now establish a new conception called 'the average vertical variability of precipitation, ' which is given by the expression Then we prove that P is a linear function of z So we can once calculate the optimal values of these two parameters by linear regression method. Using the new method, we improve the precision and the speed of calculations. We hope it is good for the more widespread application of formula ( 1 ) . At last, we give two practical examples to explain the process and characters of this new method