滴灌带之间热质传递规律研究

摘要

Soil heat and mass transfer between two drip tapes is a complex hydrothermal coupled transport problem. It presents in different forms in different soil properties and climate,so heat and mass transfer in different soils and different areas only can be studied through field measurements. In this paper,we studied the moisture distribution and the temperature distribution between two drip tapes and got the basic law of heat and mass transfer between the drip tapes in the process of fully wet and soil moisture redistribution at the southern edge of the Taklimakan Desert in Xinjiang typical climate and soil conditions.Experimental datas showed that the main reason of the sharp rise in evapotranspiration,soil salinity and the formation of saline circle or saline strips was that there were large moisture gradient and temperature gradient on the edge of wet body,which at the earth’s surface and 15~25 cm away from the drip tape when the soil was been fully wet. Reducing moisture and temperature gradients could be a effective measure to prevent soil salinization.%滴灌带之间土壤中的热质传递规律是一个复杂的水热耦合运移问题。其水热耦合迁移机制随着每个地区土壤性质、气候等的不同而呈现不同的形式，因此不同地区不同土壤中的热质传递只能通过实地的测量加以研究。该文研究了在新疆塔克拉玛干沙漠南缘典型气候以及典型土壤条件下，土壤充分湿润之后、土壤水分再分布过程中滴灌带之间的水分分布、温度分布，得到了滴灌带之间热质传递的基本数据。结果表明：在充分润湿时，距离滴灌带15~25 cm处地表，即湿润体边缘存在比较大的水分梯度和温度梯度是导致该区域蒸发量急剧上升，土壤含盐量上升，最终形成盐碱圈或者盐碱带的主要原因，降低水分梯度和温度梯度是防止土壤盐碱化的有效措施。