关键词:

Abstract: 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.