摘要
降水是山区气候中最重要的气象要素之一,其大小及变化直接关系到干旱山区中、下游的生态环境与经济社会的发展,但是,由于技术和地理条件的限制,是难以精确观测的气象要素。本研究采用天山山区31个台站和1960-2008年间的实测降水资料,应用信息熵方法对天山山区年、季和月的降水变化特征进行分析。结果表明,天山山区降水在时间和空间上均存在变异性,时间变异性表现为信息熵的无序指数(DI)年际变化小于季节变化,季节变化小于月变化。DI多年变化特征呈现下降趋势;冬季DI变化最为显著,夏季最小;冬季北坡降水随高程的增加DI变化呈显著增加趋势(P<0.05),春、夏和秋季南坡降水随高程的增加DI变化呈显著减少趋势(P<0.05)。山区月降水4-9月逐渐增加,10月至次年3月降水逐渐减少,月降水DI的变化与降水变化呈反相特征。在空间上DI变化与降水的分布相反,表现为南强北弱,东强西弱,伊犁河谷降水DI变化最小。结果证明,DI方法能够有效地分析山区降水的时空变化特征,为合理开发山区的水资源提供科学依据。
Precipitation plays a major role in maintaining the water supply in Mountainous area,which directly impacts the development of ecology environment and economic society in the mid and down streams of arid regions.Due to the technical and geographical limitations,one difficult problem in precipitation study is to accurately observe the meteorological factors.The entropy is used in this study to investigate the spatio-temporal variations of precipitation in annual,seasonal and monthly time series from 31 stations located in the Tianshan Mountain during 1960-2008.The results showed that there was an obvious spatial-temporal variability of precipitation in the Tianshan Mountain.The variability of precipitation of annual entropy was less than that of the seasonal,which is in turn less than the monthly.The decreasing trend of annual entropy was significant.In seasons,the variability of entropy was very significant in winter,but not in summer.The variability of entropy exhibited difference between precipitation and elevation for seasons.There was an increasing trend in the precipitation in northern slope with the elevation increase,while decreasing in southern slope of Tianshan Mountain in spring,summer and fall.The precipitation increased from April to September,and decrease from October to March of next year.The variability of monthly entropy and precipitation were antithetical.The spatial variability of entropy was more radical in southern and eastern slope than northern and western slope.The variability of entropy was minimal in Ili River valley.Obviously,the spatio-temporal variations of precipitation can be depicted by entropy,and supply a scientific basis to the rational development of water resources in Mountain area.
出处
《草业科学》
CAS
CSCD
北大核心
2016年第4期645-654,共10页
Pratacultural Science
基金
国家重大科学研究计划项目(2013CBA01806)
国家自然科学基金资助项目(41130638
41361013
31300388
41271078)
关键词
气候变化
降水变化
信息熵
天山山区
climate change
variation of precipitation
entropy
Tianshan Mountain
