Based on the analysis of daily p recip itation of 62 weather stations in Gansu Province from 1960 to 2005, it educed the characteristics of spatial variation of different intensity p recip itation days and p recip itation relative extremes, and those can reflect the structure of p recip itaiton. The results show that there isn’t any homogeneous variation over the whole p rovince for each indicator, and the spatial distinction of p recip itation variation is great. Thus, the regional average of p recip itation ismeaningless and the structure ismore powerful to exp lain the change of p recip itation, for which decomposed the dim unitary situation into vivid particular phenomena. The farther research on spatial variation of p recip itation structure indicates that a significant variation of p recip itation in a specific region is a synthetical consequence of the interactions among all indicators. This synthesis p rocedure is very comp licated, and usually has not broad rep resentation. Even nonsignificant variation of each indicator can bring forth a significant variation of p recip itation.

Firstly,the working p rincip le and measurement p recision of the Airda - 3000Q type atmospheric wind p rofiler (AWP) were introduced. Then, a contradistinctive analysis on the wind p rofile data acquired by both AWP and synchronous balloon sounding was conducted to estimate the reliability ofAWP for detectingwind field. The results show that under the stable weather condition, the p rofiler’s detection ofwind direction and wind speed had some deviation compared by the balloon’s detection from the ground to 200 m height due to the detecting blind spots of the AWP and the ground clutter, but above 200 m, both wind field p rofiles correlated well;Under the comp lex weather condition, theirwind p rofiles had obvious deviation because the wind information on the different height acquired by AWP is a temporal average of wind field in a time period, but the wind data measured by sounding balloon on a specific height is the instantaneous value while balloon passed by.