摘要
采用中子水分仪、负压计和电子测温器同步测定腾格里沙漠邓马营湖包气带０～４２５ｃｍ范围内不同深度含水量、基质势和温度，确立有关的水热特征参数。基于Ｐｈｉｌｉｐ、ＤｅＶｒｉｅｓ提出的土壤内水热运动理论，建立并解算了该包气带水、汽、热运动的耦合模型，并对不同气象条件下沙漠包气带水热状况进行数值模拟和预报，其结果反映了沙漠包气带含水量变化及温度分布特征。
Water content, potential energy and temperature at the depth of 0￣425 cm had been observed for three years from 1992 to 1994 in Tengeer desert by using neutron soil moisture probe, negative potential meter and electronic temperature meter. Moisture in unsaturated zone of arid desert area is so scarce that its transport is effected not only by gravity and capillary attraction, but also by temperature field. In order to understand the mechanism of moisture transport controlled by both water gradient and temperature gradient, and the relationship between water distribution and thermal current difference in unsaturated zone, a new coupled model of water-vapor-heat transport in unsaturated zone has been developed based on the theory of moisture and heat transport in unsaturated soils put forward by Phlip and De Veris. In addition, a lot of thermodynamics parameters related with water transport, thermal diffusion and thermal conduction of vapor were calculated. Finally, moisture and heat condition was simulated and forecasted in different meteorological situation. The model has been calibrated and validated with water content and temperature data observed from June 1993 to May 1994. The numerical simulation curves of water content and temperature distribution timely and spacely tallies good with the observation ones. The error of water content is 0 1%￣0 8%,mean error is 0 5%. The error of temperature is less than 0 4%and mean error is 0 2%. The simulated results show accurately the law of water-vapor-heat transport and the relationship between potential field and temperature field in unsaturated zone of arid desert area. The temperature in unsaturated zone changes in pace with climate changing. The temperature at the depth of 425 cm is three months later than that on the surface. That is to say, the lowest temperature appears in April to May while the highest in September to November. Controlled by temperature field and seasonal rain water, water content in unsaturated zone changes periodically, and water distribution varies at different depth. From 0￣40 cm, it is about 1 5%￣12%;from 40￣100 cm, it is 4% and from 100￣425 cm, it is 2 5%￣3 5%. The highest water content appears in July to August in the unsaturated zone.
出处
《中国沙漠》
CSCD
北大核心
1998年第4期340-345,共6页
Journal of Desert Research
基金
国家自然科学基金
关键词
腾格里沙漠
包气带
耦合模型
水汽
热量
Tengeer desert Unsaturated zone Coupled model Numerical simulation
