1960—2014年祁连山日照时数时空变化特征

Temporal and Spatial Variation Characteristics of Sunlight Hours in the Qilian Mountain,China from 1960 to 2014

基于祁连山区及其周边气象台站的日照时数数据,利用M-K突变检验法、滑动t检验法、Morlet小波分析方法与ARCGIS空间分析方法对祁连山东段、中段与西段1960—2014年期间的日照时数时空特征以及影响因素进行了分析。结果表明:祁连山区的多年平均日照时数整体上表现出下降态势,其中东段下降最快;日照时数年内变化5月出现最大值,这与该月的天气多晴天有关;夏季与冬季的日照时数突变在四季中表现得最明显,突变开始的年份分别为2000年与1983年;日照时数振荡周期可能为28年。祁连山区年日照时数整体上呈现东南低西北高的分布规律;夏季与冬季各区段的日照时数均为下降态势;祁连山区日照时数的主要影响因素为水汽压、云量、年降水量以及相对湿度。

Based on the data of 1960-2014 collected at meteorological stations in the Qilian Mountain and its surrounding areas,the spatial and temporal characteristics of the sunlight hours and its influencing factors in the eastern,the middle and the western Qilian Mountain were analyzed by using Mann-Kendall test,moving t-test,Morlet wavelet analysis method and the spatial analysis method of ARCGIS.Results showed that the average annual sunlight hours in the Qilian Mountains presented a downward trend as a whole,in which the drop in the eastern Qilian Mountain was the fastest;The maximum value of sunlight hour change in a year was May,which was closely related to the sunny weather of the month;Abrupt changes in sunlight hours were most pronounced in summer and winter of a year,and they began in 2000 and 1983,respectively;The oscillation period of sunlight hours may be 28 years.The distribution of annual sunlight hours in the Qilian Mountains was featured by a pattern of low values in the southeast and high ones in the northwest.The values of sunshine hours over whole sections of the Qilian Mountains was decreasing in summer and winter;The main factors regulating sunshine hours in the Qilian Mountains were water vapor pressure,cloud cover,annual precipitation and relative humidity.