【摘要】 通过对景电灌区一个冻融周期的现场观测,发现盐渍化土壤冻结期缩短,冻结深度减小,冻结起始位置不是地表,而是位于地表以下某个深度,这导致在冻结发展期间有两个冻结锋面出现,使水热盐动态更为复杂。更多还原

【Abstract】 The Jingtai Irrigation Zone with an acreage of 200km is located alongside the upper reaches of the Yellow River, in Gansu Province, Northwest China. Under the control of arid and semiarid climate, besides the influence of strong evaporation it is subject to strong effects of seasonally freezing and thawing processes as well. The uneven distribution of salt and water makes the freezing point of soil different from one depth layer to another. It is found based on the field investigation that the frozen period of salinized soil was shorter and the maximum frozen depth shallower. The starting position of soil freezing is from a certain depth below the soil surface other than from the soil surface. The freezing characteristic makes the salt-water-heat dynamic more complex due to two freezing fronts occurring during freezing.更多还原