Abstract:

 Combined with the 3″DEM data and the precipitation data in rainy season (from May to September) at 102 weather stations in the east of QinghaiXizang Plateau, we have divided the stations into three classes according to the precipitation distribution with altitude The models of the relationships between the precipitation and various geographical and topographical factors were built up based on regression analysis, and the precipitation and latent heat of condensation in rainy season were evaluated over the past 46 years (19612006) The results showed that the correlation between the precipitation and those factors are remarkable; the correlation coefficients are 069, 082, 090, respectively, which past the 005 confidence test The distribution of latent heat of condensation is inhomogeneous in the east of the plateau, that is, higher in the southeast of the plateau and lower in the northwest of the plateau The east of the plateau is divided into 5 climate subareas by using EOF and REOF methods; the temporal variation in total latent heat of condensation of the east plateau is in consistent with the latent heat of condensation in A,B,E regions, but is inconsistent with the latent heat of condensation in C, D regionsThe total latent heat ranges from 181×1020 J to 268×1020 J; the trend of its variation is increasing; the average latent heat is 219×1020 J. Because of the positive adjusting effect of altitude, longitude and slope gradient and other factors on precipitation in lower altitude regions, the latent heat of condensation in these regions are decreasing since 1990s Because of the positive adjusting effect of slope gradient and the negative adjusting effect of latitude on precipitation in high altitude regions, the latent heat of condensation in these regions are increasing with fluctuations

Key words:

 east of QinghaiXizang Plateau; latent heat in rainy season; 3″DEM; topographical factors; geographical factors