季节冻土层
seasonal frozen soil layer
等效冻土层系数
equivalent coefficient of heat conductivity
冻土层界面
interface of frozen stratum
1m土层NO3--N
NO3- --N contents at 1 m soil depth
季节性冻土区
seasonal frozen soil region
The seasonal frozen soil region
Ⅲ类季节性冻土场地
third kind seasonally frozen ground