中國幾個水旱年份降水與溫度分佈的初步分析

A PRELIMINARY SURVEY OF RAINFALL AND TEMPERATURE DISTRIBUTIONS OF SOME FLOOD AND DROUGHT YEARS IN CHINA

一、引言关于我国降水问题,过去曾有许多学者作过研究和考察。竺可桢教授于1934年曾指出锋面和气旋为中国东部降水的两个重要因子,并提到夏季北来风对于降水的重要作用。此后除了寒潮问题继续有人作过研究外,关于冷空气的活动及其在夏季对降水发生影响几个方面,亦已展开了研究和讨论。在研究方法上。

In this paper, the characteristic fcatures of the annual and monthly rain- fall and temperature distributions in the ycars 1934--35 are illustrated. The corresponding characteristies and their differences of increase or decrease of temperature in the superfluous and deficient rainy regions from the fore winter to the summer of each year have also been pointed out by meams of the inter monthly variation charts of temperature ~ Put,lng-the question of the typhoon rain aside,we may find 1)that in the summer half year of these two years,the occurrence of superfluous rainy regions of belt fbrm was mostly accompanied with thc condition of~ lnonthly mean temperature' contrast or of conflict between intermonthly increase and decrease of temperature and that the much lower tile temperature of tlle cOl~] center, the more' plentiful will be the precipitation within the rainy belt, 2 )that the superfluous rainy regions of circular form are mostly in the mountain, ranges or on highlands and,moreover,some of them are ~:eeompanied with the condition of temperature contrast or a ]ow center of temperature, 3 )when the country is intensely heated on a large scale, the most deficient rainy regions and a part of superfluous rainy regions of circular form ,re of common occurrence. The driest regions are mostly located at the monthly mean maximum high center or intermonthly m,Lximum increasing center of temperature; and" within f, h8 sa~ conditions~ there may I~ an individual exception in the regions of complex topography or of indefinite weather systems, but it is l^ssibly due to the tol)O~ graphical or cyclonic influences. Attempts have been m~:de to classify the whole country into seven regions. The tendency of correh, tion between rainfall and temperature (luring the summer half year in each region is illustrated, and it has I^ecn found out that both in the Yangtze ~nd Hwan.~ Ho Vallics the following correlation holds good: the higher thc net values of temperature departure~ the lower the corresponding net values of rainf^ll departure will be and vice versa. Morcover~ the latitudinal distributions of the jet strzam~ the importance of' the mc, n frontal positiong and of the cyclonic tracks~ the development and intensity of' the anticyclones of the Sea of Okhotsk,the Siberea and the Pacific Ocean during the summer half year arc all taken into consideration. The influ- ences of land and sea~ the topographical and local conditions are also discuss- ed by so e examples.