2009-2010年青藏高原土壤湿度的时空分布特征

利用2009年7月1日至2010年6月30日中国气象局研制的多源土壤温湿度融合分析产品, 分析了青藏高原地区不同深度的土壤湿度分布特征. 结果表明: 青藏高原土壤湿度具有显著的季节变化特征, 即春季土壤湿度最大, 夏季次之, 秋季最小; 土壤湿度呈现出浅层和深层低湿、中间层高湿的特点, 且土壤湿度由浅到深层变化幅度逐渐减小. 随着温度回升, 3-8月为土壤湿度增加时段, 湿度增加区域从藏东南向西北、塔里木盆地向藏东北扩展, 9月以后土壤湿度呈大范围减小. 随着季节变化, 浅层土壤湿度高湿度区域从南部向北部移动, 中间层土壤湿度的变化与浅层相反, 深层土壤湿度季节变化差异不大, 高湿度区域基本位于高原南部.

Spatial and temporal distribution of soil moisture over the Tibetan Plateau during 2009-2010

The soil moisture dataset derived from China Land Data Assimilation System of China Meteorological Administration from 1 July, 2009 to 30 June, 2010 are used to investigate the variation characteristics of soil moisture at different depths over the Tibetan Plateau. Results show that the soil moisture has significant seasonal variation, namely the soil moisture is the maximum in spring, followed by summer and the minimum in autumn. The soil moisture appears the characteristics with lower moisture at shallower layer and deeper layer, while it has higher moisture between the shallower layer and deeper layer, and the variation range decreases gradually from the shallower layer to the deeper layer. With the rise of air temperature, from March to August is soil moisture increasing period, and the area with high moisture expands not only from the southeast to the northwest of the plateau, but also from Tarim Basin to the northeast regions of Tibet. Beginning from September, the soil moisture presents wide-ranging decreasing, with the area with high moisture moving from the south to the north of the plateau at the shallow layer, but opposite at the middle layer. The seasonal difference of soil moisture at deeper layer is quite small and the areas with high moisture are almost located in the south of the plateau.