关键词: 降水量; 精度评估; 时空分析; TRMM; 内蒙古地区;

Abstract: In order to comprehensively and carefully study the spatio-temporal variation of precipitation in Inner Mongolia, the accuracy of TRMM 3 b43 V7 precipitation product is evaluated by using the precipitation data measured by meteorological stations from 2001 to 2018,and the Sen-MK test and coefficient of variation method are used to analyze the spatial and temporal characteristics of precipitation in Inner Mongolia.The results show that there is a significant positive correlation between the TRMM precipitation data and the measured data from meteorological stations at the monthly, annual, and seasonal scales.The fit goodness is above 0.85(P<0.01),which has good consistency.In terms of time distribution, the annual precipitation is between 228.95 and 403.80 mm, with a multi-year average of 301.59 mm.The precipitation has increased in the past 18 years, and the increase rate is 44.96 mm/10 a.In 2011,the accumulated precipitation changes from a downward trend to an upward trend.Except spring, the precipitation in other seasons shows an upward trend, the summer and autumn are the main contributors to the increase of annual precipitation.In terms of spatial distribution, the precipitation decreases gradually from the northeast to the southwest of Inner Mongolia, however precipitation increases in most regions.The area of reduced precipitation is mainly located in the Alxa Plateau in the west, where precipitation fluctuations are the most severe, and the change of precipitation in the east is more balanced.The area with an increasing precipitation in four seasons is higher than that with a decreasing trend.Among them, the area with a significant increasing precipitation in summer is the largest in the four seasons.

Key words: precipitation; accuracy evaluation; spatio-temporal analysis; TRMM; Inner Mongolia region;