北麓河地区多年冻土地表能量收支分析

Surface energy budget analysis in permafrost region of Beiluhe area

青藏高原地表能量影响高原生态环境的演变、水资源利用及地表工程的稳定性。以青藏高原北麓河气象站2012年10月~2013年10月气象资料和浅层地热流为基础,分析了北麓河地区地表能量收支和平衡特征。结果表明:1)北麓河多年冻土区能量平衡各分量冬季较小,夏季较大,净辐射、潜热、感热和地表土壤热通量年平均分别为72W/m^2、24.6W/m^2、65.5W/m^2和-18.3W/m^2;2)月平均感热大于潜热,年平均地表土壤热通量为负值,天然地表多年冻土处于相对稳定的状态,与五道梁、西大滩和唐古拉地区有明显区别;3)夏季降雨作用时间短暂,潜热影响有限,但降雨入渗引起的液态水分对流传热、水汽对流和扩散潜热对地表能量收支分析和土壤内部水热动态变化的影响不可忽略。

The variation of surface energy affects the evolution of the plateau ecological environment, water resources utilization, and the stability of the surface engineering structure in Qinghai - Tibet Plateau. Based on observed data of meteorological station in Beiluhe area from October 2012 to October 2013, the characteristics of surface energy budget were analyzed. The results show that each component of energy budget was smaller in winter but bigger in summer. The annual average values of net radiation, sensible heat flux, latent heat flux and surface soil heat flux were 72W/m2, 24.6W/m2, 65.5W/m2 and - 18.3W/m2, respectively. Monthly average value of sensible heat was greater than latent heat and the annual average value of surface soil heat flux was negative, which indicates the natural permafrost was in a stable condition. The characteristics of surface energy budget in Beiluhe area were obviously different from Wudaoliang, Xidatan and Tanggula areas. Summer rainfall duration was short thus the effect of latent heat was limited. However, the heat and mass transfered by convection of liquid water and water vapor, and diffusion of water vapor caused by rainfall infiltrations will have great influences on the surface energy balance and soil thermal -moisture dynamics and the influence cannot be ignored.