陇东黄土高原土壤储水量与蒸发和气候研究

利用长期土壤湿度和气候观测资料，分析了陇东黄土高原陆面蒸发和土壤储水量的年际变化及其与气候因素的关系。在近20年来，陇东黄土高陆面蒸发和土壤储水量的年际变化主要表现为逐年减少的趋势，个别季节表现为增加的趋势；年际变化的速率具有季节和空间差异性。陆面蒸发和土壤储水量随着温度的升高而减少，随着降水的增加而增加。但是陆面蒸发和土壤储水量与温度的关系不密切，与降水的关系密切。变暖不是陇东黄土高陆面蒸发和土壤储水量逐年减少的气候因素，降水的逐年减少才是陇东黄土高原陆面蒸发和土壤储水量逐年减少的气候因素。陇东黄土高原的土壤干旱化与地表蒸发关系不大，降水的逐年减少可能是土壤干旱化的根本原因。

A Study of Soil Water and Land Surface Evaporation and Climate on Loess Plateau in the Eastern Gansu Province

Using long-term observation data about climate and soil moisture, the soil water and the land surface evaporation in the last 20 years on loess plateau in eastern Gansu were estimated and the tendency of their variations and the relationship between their variations and climate were analyzed. The results indicated that the interannual variation of both soil water and land surface evaporation mainly showed a diminishing trend and an increasing tendency in the few seasons. The rates of inter-annual variation of soil water and land surface evaporation were varying in different seasons and regions. The soil water and the land surface evaporation decreased with temperature rising and increased with precipitation increasing. Response of inter-annual variation of soil water and evaporation to temperature was not sensitive, and response of them to precipitation was very sensitive. The rates of inter-annual variation of soil water and land surface evaporation were keeping with the rates of inter-annual variation of precipitation in different seasons and regions. The precipitation was the main climate factor affecting inter-annual variation of soil water and land surface evaporation.