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利用经典统计学方法,分析了冻融期北疆地区常年滴灌棉田土壤水分、盐分时空动态变化特征。结果表明:在整个冻融期,裸地处理的含水率随时间变异性较覆膜处理大;在最大冻土深度(90 cm土层)附近,土壤盐分随时间变异剧烈,属于强变异性,变异系数高达1.1左右;在深度方向上,土壤含水率呈中等变异性,而土壤含盐率则呈强变异性;在整个冻融过程中,冻结带中盐分随时间和深度的变化幅度较小;冻融期土壤存在稳定盐分累积层,该累积层的深度在120 cm土层,且不受地表覆盖的干扰。覆膜对120 cm土层以下土壤盐分运移影响较小。
Using the classical statistical method, the spatial and temporal dynamics of soil moisture and salinity in drip irrigation cotton fields in northern Xinjiang during freezing and thawing cycles were analyzed. The results showed that the moisture content of bare land was larger than that of landfill during the whole freeze-thaw period, and the soil salinity varied strongly with time near the maximum depth of frozen soil (90 cm soil layer) The coefficient of variation is as high as about 1.1. In the depth direction, the soil moisture content shows a moderate variability while the soil salt content shows a strong variability. During the whole freeze-thaw process, the variation of salinity in the frozen zone with time and depth is small The stable salt accumulation layer exists in the soil during freezing and thawing periods, and the depth of the accumulation layer is in the layer of 120 cm, which is not disturbed by the ground cover. Film mulching had less effect on soil salinity transport below 120 cm soil layer.