【摘要】 本文对海河流域大气中单位面积空气柱内的水汽含量即可降水量,以及流域的4个边界面的大气水汽通量的年际和年代际演变特征进行了详细分析。在此基础上对海河流域严重旱涝年的整层大气水汽总输送通量、纬向输送水汽通量、经向输送水汽通量以及可降水量进行了对比分析。研究结果表明,海河流域降水量和水汽输送具有显著的年代际变化特征,并且在20世纪70年代中期前后出现了明显的转折。海河流域的水汽输送受季风强度影响,且以经向的水汽输送为主,即夏季严重旱年水汽总输送减弱,到达海河流域的水汽总量减少,而夏季严重涝年水汽总输送加强,到达海河流域的水汽输送总量增多。更多还原

【Abstract】 The annual and decadal evolution of vapor content in unit area air column and vapor flux at the surrounding boundaries of the river basin in Haihe River was analyzed.On this basis,the analyses on total vapor flux in the whole atmosphere,vapor flux to be transported in latitude and longitude direction in the years occuring serious drought or logging were further carried out.It is found that the water vapor transportation in Haihe River Basin is affected by the strength of monsoon and mainly in longitudinal direction,the precipitation and vapor transported possess the characteristics of annual and decadal variation,and a turning point occurred to late 1970’s,since then the water vapor available for changing into precipitation decreases.In the summer time of serious drought years,the vapor transport capacity weakened and the total water vapor to be transported to Haihe River basin decreased.Contrarily,in serious logging years the vapor transport capacity strengthened,so that the vapor to be transported to the basin increased.更多还原