土壤中热量传输计算的研究进展与展望

Study of Calculation of Soil Heat Conduction: Progress and Prospect

土壤中热量传输计算的研究分为土壤热通量计算方法和土壤导温率计算方法两方面的成果.目前已有土壤热通量的计算方法,在土壤表层可以得到较好结果,但在土壤深层的适用性无法确定.多孔介质模型和考虑水的渗流造成的影响,是多年冻土区土壤导温率的计算方法的研究方面新的进展.为研究青藏铁路沿线冻土演化趋势找到合适的土壤热量传输计算方案,应是今后工作的一个重点.

The studies of the heat conduction in soil are of great importance both in the study on the thermal properties of soil for hydrometeorologists and in the study on land processes for micrometeorologists. The studies in this field are especially important in the study on the variation tendencies of permafrost in the Tibetan Plateau, which is directly related to the safety and stability of the Qinghai-Tibetan railway in construction. In this paper, the studies on the methods of calculating the heat flux conduction in soil are reviewed. The studies in this field are summarized into two categories, which are the methods of calculating soil heat flux and the methods of calculating soil thermal diffusivity, and both of these two categories can be divided into finer classes. At present, the methods of calculating the soil heat flux conduction can work well in the shallow layers of soil, but whether they can be well used in the deep layers of soil or not is still doubtful. Using porous media model and including the influences of water conduction in the soil into the methods of calculating soil heat flux conduction are the latest progress in the studies of the methods of calculating the soil thermal diffusivity in permafrost regions. With the more and more progress in this field, one of the important tasks in the future is to find a set of valid schemes of calculating the soil heat flux conduction, which can be used in the study of the permafrost variation tendencies along the Qinghai-Tibetan railway.