Preliminary study on land surface characteristics over Huaihe River Basin

The analysis of the flux observation dads from the Huaihe River Basin Experiment (HUBEX) shows that, in semi-humid monsoon regions, latent heat flux is as important as sensible heat flux in most situations. Moreover, it can even dominate the sensible heat flux in cropland and paddy field. This is distinct from that for arid and send-arid regions where the sensible heat flux is dominant. Under clear sky conditions, the soil temperatures in different vertical layers all exhibit certain diurnal variations, and the magnitude decreases with depth to less than VC at a depth of 60 cm. This depth is considered as the transition layer for the soil moisture variation. On the other hand, the vertical profile of soil water content varies with the soil texture and even weather conditions, and the layer with maximum soil water content can also be found in Jiangji station during June 1998.