巴丹吉林沙漠西南缘不同强度降水的基本气候特征

Fundamental Climatic Characteristics of Rainfall Events of Different Intensities over the Badanjaran Desert’s Southwestern Border Area

经分析巴丹吉林沙漠西南缘降水的强度、雨量、频次及空间尺度,发现:1) 夏(冬)季各级强度降水发生最多(少)、雨量最大(小),春、秋季相当;各季都是越强的降水越少发生;冬季较强降水所致雨量总是较小,其余三季都是中雨所致雨量最大;2) 各季各级强度降水的雨量和频次都随海拔升高而增加,尤其在暖季,海拔越高,较强(弱)降水的贡献越大(小)。3) 各季都是尺度越大的降水越少发生;所有尺度的降水都以夏季最多,冬季最少,春、秋季相当;尺度较大(小)的降水在夏(冬、春)季的配额较大;平均而言,夏季降水的空间尺度最大,秋季次之,冬季最小。4) 在任何季节,海拔越高的地方越易成为降水中心,相对而言,民乐在各季成为降水中心的可能性远高于其它测站。5) 四季都是降水中心强度越大其空间尺度也越大,但大尺度强降水很少发生,冬季更是以弱降水为主。

Through analysis on the rainfall intensity, frequency and its spatial scale, together with the precipitation amount, over the Badanjaran Desert’s southwestern border area, the following results have been disclosed: 1) Each intensity grade of rainfall events happen most frequently (infrequently) and the precipitation amount resulting from them reaches the maximum (minimum) in summer (winter), with their frequency and amount in spring being both equivalent to those in autumn;Each season is always seeing a less frequency of heavier rainfall events;In winter the precipitation amount due to heavier rainfall events is always smaller, but in spring, summer and autumn, that due to rainfall events up to the Chinese traditionally-determined middle intensity grade (10.1 - 17 mm?day?1) always reaches the largest of all. 2) In each season, rainfall events of each intensity grade happen more frequently and the precipitation amount due to them becomes larger at higher places, and especially in warmer seasons, heavy (light) rainfall events make a larger (smaller) contribution over there. 3) In each season the rainfall events on a larger spatial scale often happen more infrequently;The rainfall events on each scale occur most frequently (infrequently) in summer (winter), and their frequency in spring is equivalent to that in autumn;The larger-scale (smaller-scale) rain-fall events are more ready to happen in summer (winter and spring);On average, the rainfall spatial scale reaches the largest (smallest) in summer (winter) and it is larger in autumn than in spring. 4) The higher place is always more ready to become the rainfall center in each season, for example, Minle, as the highest station, is much more possible to act as that center. 5) The rainfall event whose center sees a higher grade of intensity always has a larger spatial scale in each season, however, the large-scale and high-intensity-grade events seldom occur, and especially winter can mainly see light rainfall events.