Study on surface water transport in agricultural landscape on the slop lands of red soil(dry season)I．Water transport at soil-atmosphere interface

A located observation and study of water transport at soil-atmosphere interface was conducted． The results show that there are differences in soil evaporation among different agricultural cultivations while no difference in the dynamic variation of water vapor transfer flux．The daily variation curve of soil evaporation is a typical single peak curve．Many factors may affect the surface water transport．When surface vegetational typ es are stable and the effects of crop are not remarkable，the water transfer at soil-atmosphere interface is affected not only by climatic condition but also apparently by soil water contents(0～20cm)．The water vapor transfer through interface is significantly positively correlated with the net radiation and is corelated with the environmental temperature．It is also affected by water potential and has a highly significant negative corelation with the air humidity．Therefore，the water vapor transfer at interface is mainly controlled by soil surface(0～20cm)water contents．Their relationship has a linear correlativity．The amount of soil evaporation is 1／3 of the total field evapotranspiration．There are potentials for controlling the consumption to these none productive water moisture．Measures such as soil-manuring，irigation-controlling，physical obstacle of preventing soil evaporation are presented．