薄层水流对土壤温度影响的格子Boltzmann法分析

Lattice Boltzmann analysis of influence of slope sheet flow on soil temperature

为分析薄层水流影响下坡面剖面土壤热量运移机理,利用格子Boltzmann方法求解了坡面水流运动方程、土壤水运动方程与热力学方程,分析定量降雨条件下坡面水流对土壤温度分布的影响。研究表明,引起热量传递的动力是温度梯度;坡面水流对土壤温度影响前期影响主要在土壤表层,随着时间进行,由于土壤温度变化具有滞后效应,进而影响到下层土壤的温度分布。降雨强度大于75 mm/h后所产生的温度场接近于降雨强度为75 mm/h产生的温度场。

In order to study the heat transformation of soil, which is affected by slope sheet flow, a Boltzmann method was used to solve the movement equations of sheet flow and soil water and the thermodynamic equation. The influence of the slope flow formed from rainfall on soil temperature distribution and the variation of soil temperature in different depth were also studied. The analysis results show that the temperature gradient is the driving force of heat transfer; and that the soil tem-perature is significantly affected by slope flow. The early stage effect is concentrated on the soil sur-face, and it goes further into deeper soil with the duration of rainfall due to the hysteresis effect of temperature change in the deeper soil. The temperature field generated by the rainfall intensity larger than 75 mm/ h is close to that generated by the rainfall intensity of 75 mm/ h.