The study was carried out at the desert oasis wetland in the middle reaches of China's Heihe River, where soil temperature, water content, electrical conductivity and evapotranspiration were measured to analyze the coupled transport of water-heat-salt and its influencing factors during the growing period and the freezing and thawing period, respectively, to discuss the controlling effects of the water-heat gradient on the migration process and the distribution pattern of salt. The results showed that soil temperature increased in spring and summer and decreased in autumn and winter. In the freezing period, soil desalinization was occurred. The surface electrical conductivity was reduced from 2.8 mS·cm-1 to 1.2 mS·cm-1. However, in the thawing period, soil salt accumulation was occurred. The surface electrical conductivity was increased from 1.2 mS·cm-1 to 3.7 mS·cm-1. During the growth period, the fluctuation of soil water content and electrical conductivity was significant, and showed the alternate appearance of desalination and salt accumulation. The surface water content ranged 27% to 43%, and the surface electrical conductivity ranged 3 mS·cm-1 to 5.5 mS·cm-1. The mean annual evapotranspiration totaled 507mm. And evapotranspiration showed a single peak trend. The relationship of the soil electrical conductivity and evapotranspiration was positively correlated. But the relationship of the surface electrical conductivity and groundwater depth was negatively correlated. Therefore, evapotranspiration was the main driving force of soil salt accumulation in soil surface, while the groundwater fluctuations affected the wetland desalination and the salt leaching process. Therefore, the accumulation of soil salinity in the desert oasis wetland was the result of the change of the water transport and the heat transfer.
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