利用COUPMODEL模型,对唐古拉研究区活动层土壤的水热特征进行模拟,与观测结果进行对比发现,在活动层土壤温度方面,COUPMODEL模型的模拟结果R2〉0.94,其平均值为0.98,均方根误差较小,模拟效果较理想;在活动层水分特征方面,模拟结果存在一定偏差,R2介于0.88-0.93之间,平均值0.90,均方根误差平均值4.24,基本反映了高海拔多年冻土区活动层水热变化;在土壤热通量方面,0-20 cm土壤热通量的模拟结果与观测值基本一致;模型模拟的冻结深度在3 m左右,接近观测值,COUPMODEL模型可用于多年冻土区活动层土壤水热变化规律研究。
To study the water-heat characteristics of soil in the active layer in high altitude permafrost regions and to examine the interaction between soil and moisture under freeze-thaw cycles, a physical process by the CoupModel was used to simulate the soil temperature and moisture in the active layer, using the meteorologi-cal, the soil thermal and the moisture data on different depths in the active layer at the Tanggula test site. Com-parisons between simulated and monitored data in situ showed that: 1) for soil temperature in the active layer, the simulated results fit well with the monitored, and the determination coefficient (R2) is more than 0.94 with the mean value of 0.98 while mean square deviation is relatively small, implying the CoupModel could suc-cessfully simulate the soil temperatures. 2) For soil moisture, results generally reflect water content variation in the active layer with R2 ranging from 0.88 to 0.93, the mean is 0.90 and the mean square deviation is 4.24, indicating a bit poor accuracy compared to soil temperature. 3) As to the heat flux of soil within the depth of 0-20 cm, results simulated is consistent with the monitored. The simulation accuracy is improved with depths, which may be related to the depth from the natural ground surface. The frozen depth is about 3.0 m, which is close to the observed data. It is concluded that the CoupModel can be well applied to study soil water-heat characteristics of the active layer in permafrost regions with higher elevations in Qinghai-Tibet Plateau.