The hydrothermal process within the aeolian sand layer on the Qinghai-Tibetan Plateau (QTP) plays a key role in understanding the interaction between desertification and underlying frozen soil. However, little is known about the hydrothermal dynamics of aeolian sand and underling soil layer in the frozen soil zone on the QTP. In this study, a sparse vegetation cover site and three aeolian sand cover sites with different sand thicknesses were established to study the hydrothermal dynamics within aeolian sand layer. The results show that the thickness of aeolian sand is critical in the soil hydrothermal process under sand cover. The increase in thickness of the aeolian sand layer resulted in an advance in the onset of the freezing and thawing of soil, and accelerated movement of the freezing and thawing front. In addition, the increase in sand thickness caused an increase in soil temperature during the thawing stage and the warming period of the thawed stage, whereas a decrease occurred during the cooling period of the thawed stage, the freezing stage and the frozen stage, which ultimately caused the enlargement of the annual range of ground temperature. Furthermore, in the study area, the actual evapotranspiration of sand-covered surface was larger than that of the naked surface. The water content also decreased with increasing sand thickness in different stages, which separately decreased the heat budget in both the warm and cold season because of the smaller thermal conductivity of aeolian sand with a lower water content. This study states that through the special hydrothermal process, have an adverse impact on the occurrence and formation of the frozen soil in the QTP.

青藏高原（QTP）的风沙层内的热液过程在理解荒漠化与下层冻土之间的相互作用方面起着关键作用。然而，关于QTP冻土区中风沙和下层土壤层的水热动力学知之甚少。在这项研究中，建立了一个稀疏的植被覆盖点和三个不同厚度的风沙覆盖点，以研究风沙层内的水热动力学。结果表明，风沙厚度是砂覆盖下土壤热液过程的关键。风沙层厚度的增加导致土壤的冻融开始，并加速了冻融锋面的运动。此外，砂层厚度的增加导致融化期和融化期升温期间土壤温度升高，而融化期的冷却期，冷冻期和冷冻期的土壤温度降低，最终导致土壤膨胀每年地面温度的范围。此外，在研究区域中，被砂覆盖的表面的实际蒸散量大于裸露表面的实际蒸散量。在不同阶段，水含量也随着砂层厚度的增加而降低，这是由于风沙含量低而风沙的热导率较小，从而分别降低了暖季和冷季的热量收支。这项研究指出，通过特殊的水热过程，