The Coupling Transfer Experimental Simulation Of Soil Water And Heat In Dune Alternated With Wetland Area In Horqin Sandy Land

This study choiced the dune alternated with wetland in Horqin sandyland as research area.Two experimental stations with 30m×30m were established in Agula water ecological experimental area which lies in Horqin Zuoyihouqi in Tongliao.One of the stations was upbuilt in wetland and another was mounted in moving dune.Ecological factors such as water,soil,atmosphere and heat were observed.The main contents and conclusions as follow: (1)The characteristics of soil water dynamic variance and the relationship between environmental factors and soil water dynamic variance.①There is a dry sand layer with 10cm depth on the surface of moving dune.The layer can effectively prevent the deeper soil water from dissipating and retain comparatively steady moisture content in each soil layer.②The relativity of soil moisture and environmental factors has been analysed using multivariate regression.The results show that the soil moisture of moving dune has the maximum relativity with surface temperature and sunshine time.However, the soil moisture of wetland has the maximum relativity with atmospheric humidity. (2)The characteristic of evapotranspiration in dune alternated with wetland area has been analysed.It can be seen obviously that the evapotranspiration of wetland covered with vegetation more than the evaporation of moving dune without vegetation. (3)The study of heat balance rule in dune alternated with wetland area.From the research result it can be seen that①soil temperature of moving dune has a greater diurnal amplitude than wetland.Meanwhile,the daily variation tendency of soil temperature of wetland comparatively gently.②In the heat balance of ecological system in dune alternated with wetland area,the latent heat flux takes the most share,in the next place is sensible heat flux and soil heat flux. (4)The coupled relationship of soil and water in dune alternated with wetland area was simulated.Applying the soil water and heat transfer model which fits for aridity and semi-aridity area,this paper actualizes the numerical simulation of water and heat transfer in soil system of dune alternated with wetland area using normal meteorological data and parameters of water and heat.