将小尺度含水层热机械弥散系数模型应用于对流弥散传热过程中，推导了该条件下对流弥散热量运移的解析解，结合试验进行验证，对含水层热弥散效应进行评估，结果表明，热机械弥散系数等于1×10-2 W/(m?°C)可以作为热弥散对温度场影响的临界点，从而将热机械弥散系数的分布划分为不可忽略的三角区域和可以忽略的多边形区域；明确了自然含水层结构条件下纵向热弥散度范围，从小尺度的热弥散研究结果来看，纵向热弥散度最大值为厘米数量级，它与野外大尺度条件下热弥散度的研究成果有着显著差异，表明热弥散尺度效应的存在，这将是进一步开展研究工作的方向。

This paper uses a thermo-mechanical dispersion coefficient model in a small-scale aquifer to examine the advection- dispersion heat transfer process. Analytical solutions of advection-dispersion are derived and proved their correctness with experiment. The assessment results show that the coefficient of the thermal-mechanical dispersion of 1×10-2 W/(m?°C) can be selected as the critical point where thermal transport is affected. The distribution of thermal mechanical dispersion coefficients can be divided into non-ignorable triangular domain and ignorable polygon domain. The calibration scope of longitudinal dispersion degree of natural flow field is made clear in different aquifers. However, the research result of small scale thermal dispersion show that, under condition that the particle diameter and the seepage velocity are both at the upper limit, the maximum of longitudinal thermal dispersion degree is at centimeter order of magnitude, which is significantly different from the research result of thermal dispersion degree under outdoors of large scale conditions. This proves the existence of scale effect of thermal dispersion, and thus shows the direction of further research.