利用"我国西北干旱区陆-气相互作用试验"在甘肃省敦煌的观测资料,分析了不同大小的降水对土壤湿度、反照率以及地表温度的影响;随着降水量的增大,各地表物理量恢复到原先的状态也越慢;强降水时,5cm土壤湿度的驰豫期为7天,中降水为4天,微量降水为2天。由于降水性质(水和雪)和土壤状态的差异,冬季和夏季相比,降水对地表物理量的影响差不多,但冬季地表物理量的恢复时间要比夏季长得多。土壤湿度和反照率的驰豫期与降水有很好的相关。

Utilizing the data of the "experiment on land-atmosphere interaction over arid region in Northwestern China" in Dunhuang, Gansu Province, the effect of different rainfall intensities on soil moisture, albedo and surface temperature are analyzed.With the precipitation increasing, the time of surface physical variable restoring to primary state is longer.The relaxation time of soil moisture at 5 cm is about 7 days under heavy rainfall condition;middle rainfall, 4 days;and small rainfall, 2 days.Both the effect of surface physical variable on rainfall in winter and summer is similar, but the restoring time in winter is longer than one in summer because the character of rainfall and soil state is different.The correlation between the relaxation time of soil moisture and albedo with rainfall is good.