用卫星云图估计我国西北干旱地区秋季降水的试验

ESTIMATION OF AUTUMN PRECIPITATION OVER THE ARID AREAS IN NORTHWEST CHINA USING SATELLITE IMAGERY

利用卫星红外云图资料和实测降水记录,分析影响我国西北干旱半干旱地区秋季降水的云种,并建立9、10、11月和秋季(9—11月)的逐日降水量估计的回归方程,并将它用于无资料地区的日降水量和逐月降水量的估计。结果表明,日降水量在1.0—15.0mm范围内,降水估计偏差较小,当日降水量在0.1-1.0mm范围和≥15.0mm时,降水估计偏差较大。同时,月降水量估计值与实测值的分布形势大体一致。

Based on satellite infrared cloud pictures and surface rainfallobservational data, the distribution features of autumn precipitationcloud species affecting the arid and semi-arid areas in Northwest chinaare analyzed, and regression equations are established for estimating thediurnal precipitation in September-November. These equations can beused to estimate daily and monthly precipitation for the areas short ofdata. Results show that when diurnal precipitation is within the rangeof 1.0--15.0mm, errors will be small, but the opposite is true when itis within the range of 0.1--1.0mm or≥15.0mm. The estimated monthlyprecipitation values are generally in agreement with the distributiontrend of the observational data.