Zhang Letian, Hao Zhenchun

Water Environment Institute of Hohai University, Nanjing 210098

Abstract: This paper conducted experiment and research on the two different evaporation data of Huaibei plain and the lower Yellow River area and studied the different underlying surface condition and mode of evaporation, the water consumption and its trend of change were calculated and analyzed. The underlying surface condition of the lower Yellow river area is very complex with water surface but distributing great deal bare bottomland and crops, while Huaibei plain is an alluvial plain deposited by various floods occurred both in the Yellow River and Huaihe River, there has difference on soil texture and recharging modes of groundwater and thus caused different influence of phreatic water on evaporation. This paper adopted research methods combined by theoretical arithmetic and physical model experiment, using Pen-man-Monteith Formula recommended by FAO to calculate potential evaporation standing for water surface evaporation, as the great meteorological data volume needed for Pen-man Formula, this paper simplified and validated the rationality, meanwhile using Avey Yang Knoff empirical formula to calculate phreatic evaporation of the two areas and then to seek the changing laws and trends of soil evaporation with phreatic depth.

Key words: The lower Yellow River, Huaibei plain, Evaporation experiment, phreatic evaporation