荒漠地区地表反照率与土壤湿度相关性研究

The Dependence of Surface Albedo on Soil Moisture in An Arid Desert Area

本试验分别对腾格里沙漠东南缘沙坡头地区流动沙丘和1964年建植的人工固沙植被区生物土壤结皮的地表反照率和土壤湿度进行了同步测定。分析了该区这两种地表类型的反照率与太阳高度角和土壤湿度的相关性,分别提出了地表反照率与太阳高度角和土壤表层（0~2 cm）湿度的经验拟合关系式。结果表明,地表反照率随太阳高度角增加呈指数递减;排除太阳高度角的影响后,地表反照率随土壤湿度的增加也呈指数递减关系;流沙地表反照率对土壤湿度变化的响应要比生物土壤结皮地表敏感。

The surface albedo and soil moisture of sand dune and biological soil crusts were measured concurrently in field plots of a moving sand area and an artificially revegetated area established in Shapotou in southeasten edge of the Tengger Desert in 1964.We mainly aimed to study the relationships between surface albedo and solar elevation angle and surface soil moisture.The empirical formulas relating surface albedo to solar elevation angle and to surface soil moisture were proposed.The results indicated that surface albedo has an exponential function with solar elevation angle,and the normalized surface albedo decreases exponentially with the increasing of surface soil moisture in condition of removing the solar elevation angle effects.Moreover,the surface albedo of sand dune was found to be more sensitive to the response of surface soil moisture than that of biological soil crusts.The response of surface albedo to soil moisture varied with land surface types,which may be related to soil color or/and innate attributes of soils.