摘要
根据乌鲁木齐河流域9个气象站1961-2009的逐月降水量资料,采用三维二次趋势面宏观地理因子模拟与反距离平方加权残差订正相结合的方法,建立全流域年降水量变化倾向率、突变前后降水增量、年和各月降水量多年平均值以及年降水量变异系数等降水量气候要素空间分布数学模型。在ArcGis平台上进行数据栅格化处理,实现基于数字高程模型(DEM)数据的乌鲁木齐河流域降水量时空变化的精细化分布式模拟。结果表明:(1)196l-2009年,乌鲁木齐河流域年降水量平均以15.29mm/10a的倾向率呈显著(P<0.05)的递增趋势,并于1987年发生了突变性增多,但各地降水量增多倾向率和突变前后降水增量差异明显,总体表现为海拔越高的区域,降水量增多越明显。(2)乌鲁木齐河流域年降水量的空间差异十分明显,流域末端的北部平原降水量不足250mm,向南随着海拔的升高降水量渐增,在海拔1900-2200m的天山北坡中山带出现降水量为550~600m的最大降水带,之后,随着海拔高度的继续上升,降水量又呈减少趋势,至3500m以上的河流源头区域,年降水量不足450m。(3)年降水量变异系数随海拔的升高而减小,即海拔越高的区域降水量的年际间波动相对越小。(4)年内逐月降水量的空间分布格局表现为明显的周期性变化特征。冬季(12-2月)降水较少,各月降水量的高值区主要在低山带和山前洪积、冲击平原,而降水量的低值区在海拔2500m以上的高山带。春季(3-5月)降水量较冬季多,降水量的高值区也逐渐向高海拔山区上移,而降水量低值区则由南部高山带逐渐向北部平原迁移。夏季(6-8月)是一年中降水量最多的季节,各月降水量的高值区逐渐上移到海拔2000-4000m的中、高山带,而降水量低值区在北部平原地带。秋季(9-11月)降水量逐渐减少,最大降水高度带也向低海拔区域移动,而降水量低值区则向中、高山带上移,至11月,最大降水带回复到低山带和山前洪积、冲击平原地带,最少降水带再次上升到2500m以上。
Based on the monthly precipitation data of nine meteorological stations in 1961-2009 in Urumqi river basin,the refinement spatial-temporal variation characteristics of annual precipitation change trend rate,annual precipitation increment after and before it sudden change,mean precipitation of annual and monthly,the variation coefficient of annual precipitation in recent 49 years were analyzed by using methods of three-dimensional and quadratic trend surface simulation and against-distance square weighting residual error revising based on DEM.The main results were as follows.(1)The average annual precipitation of nine meteorological stations was increasing by the change rate of 15.29mm/10y,and the annual precipitation had the discontinuity ascension in 1987,but the change rate and annual precipitation increment after and before annual precipitation sudden change was different in each region in Urumqi river basin,generally,the increase rate and increment of annual precipitation was more in higher altitude areas than in lower altitude areas and plain in Urumqi river basin.(2)The spatial variation of annual precipitation was very obvious,precipitation was less than 250mm at the end of Urumqi river basin,to the south,along with the increase of altitude,precipitation was increasing,the most annual precipitation occurd at altitude of 1900 to 2200m,and the most precipitation was 550mm to 600mm correspondly.After this,precipitation had a decreasing trend with the altitude continues rise,to the river source area of above 3500m,the precipitation was less than 450mm.(3)Annual precipitation variation coefficient was smaller in higher altitude mountain than in lower altitude areas and plain in Urumqi river basin.(4)The spatial distribution of monthly precipitation in a year performance for the obvious periodical change characteristics.Precipitation was less in winter(December to February),the area of the most precipitation was mainly in the lower altitude mountain and the piedmont plain,and the least precipitation zone was mainly in elevation above 2500m.In spring(March to May),precipitation was more than winter,the most precipitation zone was moving up to higher altitude mountain,and the least precipitation zone was moving from higher altitude mountain to the plains migration gradually.Summer(June to August) is the season of greatest precipitation in a year,the most precipitation zone move up to medium and higher altitude mountain belt of 2000-4000m,and the least precipitation zone in northern plains.In autumn(September to November),the precipitation was reducing gradually,the most precipitation zone was also moving to lower altitude area,and the least precipitation zone was moving up to medium and higher altitude mountain belt gradually,to November,the most precipitation zone revert to lower altitude area and piedmont flood impact basin deposition,and the least precipitation zone rising up to higher altitude mountain belt of above 2500m again.
出处
《中国农业气象》
CSCD
2011年第3期437-443,共7页
Chinese Journal of Agrometeorology
基金
新疆气象科研项目(200708)