半干旱地区吉林通榆“干旱化和有序人类活动”长期观测实验

The Long-Term Field Experiment on Aridification and the Ordered HumanActivity in Semi-Arid Area at Tongyu, Northeast China

简单介绍了吉林通榆“干旱化和有序人类活动”长期观测实验 ,该实验站同时也是国际协同加强观测计划 (CEOP)的地面观测站。分析了 2 0 0 2年 1 0月～ 2 0 0 3年 3月 (CEOP EOP3)非生长季观测到的近地面层微气象及能量通量资料。结果表明 ,在非生长季 ,半干旱地区农田和退化草地下垫面近地面层能量收支基本一致 ;感热通量占主要地位 ,占净辐射通量的 70 %左右 ;潜热通量及地热流都很小 ,通常小于 30Wm- 2 。土壤温度日变化主要集中在地表以下 2 0cm土壤层 ,2 0cm以下土壤温度日变化很小 ,但存在明显的季节变化。在非生长季 ,土壤表层 1 0cm厚度内 ,草地下垫面土壤体积含水量比农田大 ;2 0cm以下深度土壤体积含水量的日变化很小 ,同样存在季节变化。

A brief introduction has been given about the long-term field experiment on aridification and the ordered human activity in semi-arid area at Tongyu, Northeast China. This observation station is also one of the reference sites of Coordinate Enhanced Observation Period (CEOP). The micrometeorology and energy flux data collected during CEOP-EOP3 from October, 2002 to March 2003 has been analyzed. During the period, there is no vegetation on the cropland surface. The surface energy budget over cropland and degraded-grassland is almost the same. The sensible heat flux is almost 70% or so of the net radiation flux. The latent heat flux and the surface soil heat flux are almost less than 30 W m -2. The diurnal variation of the soil temperature is just in the upper 20 cm layer soil. The soil temperature below 20 cm has very little diurnal variation, but has seasonal variation. The volumetric soil water content in the upper 10cm over degraded grassland surface is larger than that over the cropland surface. The volumetric soil water content below 20 cm also has seasonal variation.