干旱及高寒荒漠区土壤温湿度特征及相互影响的分析

根据黑河试验1991年6月20日～8月21日、1990年12月17日～2月15日每天48个时次和第二次青藏高原试验改则及狮泉河1998年全年每天24个时次的土壤温湿度资料，采用功率谱分析、PCA分析等方法，分析了干旱及高寒荒漠区两种典型下垫面土壤温湿度的时空分布特征及其相互作用。结果表明：土壤温度除日和年变化周期外还存在6～30天的不同周期；下垫面的非均匀性及其季节变化及温度梯度变化对土壤水分运动有很大的影响，冬季温度梯度变化对土壤含水量的影响大于夏季温度梯度对土壤含水量变化的影响，且温度梯度与水分运动方向相反。

Variation Features of Soil Temperature and Moisture Content at Dry-and Alpine-Desertification Surface and Their Interaction Analyse

On the basis of observed data, the spatial-temporal variation characteristics of soil temperature and its effects on soil water movement in two kinds of underlying surfaces of Heihe, Gaize and Shiquanhe are studied. In which the Heihe River valley is as a representative of the typical dry desertification underlying surfaces; and Gaize and Shiquanhe Stations over Qinghai-Xizang Plateau, one of alpine desertificat underlying surfaces. The results show that there exit the several periodic variations for soil temperature at different depths ranging from six to twenty four days in Heihe region, and from nine to thirty days in Gaize and Shiquanhe region. It also shows that the gradient of soil temperature affects the soil water content movement more greaterly in summer than in winter.