新疆夏季0 oC 层高度变化对河流年径流量的影响

按气候特点和河流径流情况把新疆划分为阿尔泰-塔城、天山山区和昆仑山北坡3个研究区域.采用1960～2002年新疆12个探空站逐日观测资料和34个水文站的年径流资料,利用经过5点平滑处理的曲线趋势对比和线性相关的研究方法,定性与定量相结合分析了43年来新疆夏季0℃层平均高度变化和河流径流变化趋势及空间分布差异,并建立了二者的定量关系式.研究表明:新疆夏季0℃层平均高度与河流年径流量变化具有较好的一致性,尤其是1970年代以来.两者的变化趋势更加亦步亦趋.各区变化不尽相同,阿尔泰-塔城和天山山区为1990年代初以来夏季0℃层平均高度为显著升高地区,昆仑山北坡为下降区.与之相对应,同期前两个地区的河流径流量也显著增大,后一个区域的径流量略为减少.就相关性而言.新疆全区和分区的天山山区以及昆仑山北坡等地的夏季0℃层高度与河流径流量均有较好的相关性.均通过了0.01显著水平的统计检验.表明新疆近年来不仅近地面发生了气候变化.高空也同样发生了类似的变化,并直接导致了夏季0℃层高度的升降.气候变暖,新疆夏季0℃层升高.山区的冰雪消融加快,河流径流量相应增多,进入丰水期.反之,进入枯水期.夏季0℃层高度的升降直接影响新疆河流径流量,在新疆气候暖湿化过程中,高空的增温也是一个较直接的因子.

The Response of Annual Runoff to the Height Change at the Zero Temperature Level in Summer over Xinjiang

Xinjiang is divided into three regions: the Altay Mountains-Tacheng, the Tianshan Mountains and the northern slope of the Kunlun Mountains by the climatic feature and their runoff. Based on the daily observed materials from 12 air sounding meteorological stations and the annual runoff materials from 34 hydrological stations during the period of 43 years from 1960 to 2002, the mean height change at the 0 ^oC level, the changing trend of runoff and their deviation of spacial distribution were researched in Xinjiang according to the methods of the combination of qualitative and quantitative analyses and the contrast with the five-year smoothing mean curve. The results show that there exists a better coherence between the height change at the 0 ^oC level and the annual runoff amount of the rivers in Xinjiang, and this kind of correlation has especially turned closer since 1970. Each region had its own unique feature that the heights have been significantly ascending over Altay Mountains-Tacheng and Tianshan Mountains, and that the height has been lowering over the northern Kunlun Mountains since 1990. Correspondingly the runoff over the former two regions has been increasing and over the latter has been slightly decreasing in the same period of time. In terms of relativity, there exist better linear correlations at the significance level of 0.01 between the height at the 0 ^oC level in summer and the runoff over Xinjiang as well as the Tianshan Mountains and the northern slope of the Kunlun Mountains. Recently, the height change at the 0 ^oC level has been resulted not only from the climate change on the ground but also from the upper climate change in Xinjiang. Along with the climate warming, the ascend of the height at the 0 ^oC level and the increase of melting snow in mountains, the runoff is accordingly gaining so that Xinjiang is witnessing the period of abundant water, and vice versa. So the runoff is directly resulted from the lifting of the height at the 0 ^oC level in summer. The increase of temperature in the upper air is one of the immediate factors during the course that the climate in Xinjiang is getting warmer and wetter.