临汾市土壤热扩散率和液态水通量密度研究

Research of Soil Thermal Diffusivity and Liquid Water Flux Density at linfen City

利用临汾市基本气象观测站的土壤温度资料,采用同时考虑热传导和热对流的土壤温度算法研究了临汾市的土壤热扩散率和液态水通量密度.结果表明:两参数垂直方向上均不同性,平均而言,4月、7月的土壤热扩散率随着深度增加而增大,而10月的土壤热扩散率随着深度增加而减小;三个月的液态水通量密度均在土壤深度0.025 m与0.075 m之间减小,4月液态水通量密度在土壤深度0.075 m与0.125 m之间增大,在土壤深度0.125 m与0.175 m之间减小,7月和10月的液态水通量密度变化情况与4月则正好相反;土壤热扩散率和液态水通量密度均存在月际差异,各深度层变化不一致.

A method coupled thermal conduction and convection, first proposed by Zhiqiu GAO, to determing the accurate values of soil thermal diffusivity and liquid water flux density is introduced, using this method we determined the soil thermal diffusivity, k =0.10 × 10^-6m · s^-1 ～ 5.24 × 10^-6m · s^-1, and liquid water flux density, W = -6.39× 10^-6m^2 · s^-1～2.65 × 10^-5 m^2 · s^-1. The results show that soil thermal diffusivity and liquid water flux density are vertically heterogeneous, on average, the soil thermal diffusivity increase in April and July while decrease in October with increasing soil depth, the liquid water flux density decrease between soil depth 0. 025 m and 0.075 m in these three months, it increase between soil depth 0. 075 m and 0. 125 m and decrease between soil depth 0. 125 m and 0. 175 m in April, which is just the opposite in July and October; The soil thermal diffusivity and liquid water flux density have monthly differences, which are inconsistent between different soil depth.