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对比研究了新疆奇台县绿洲农田灌溉前后土壤水盐的时空变异特征。结果表明,灌溉前,剖面各层土壤含水量较低(18.43%～20.30%之间),且呈中等(偏弱)变异性。大水漫灌后1周,除40～60cm和100～120cm土层外,其他层土壤含水量均变为弱变异性;剖面平均土壤含水量升高6.90%,脱盐率达11.37%,其中,表层(0～20cm)土壤水分增加率(50.93%)及脱盐率(27.14%)最大,底层(100～120cm)土壤水分增加率(26.59%)及脱盐率(-4.76%)最小。灌后3周,剖面平均含水量减少3.64%,其中,表层(0～20cm)失水率(28.84%)最大;剖面平均脱盐率降为9.63%,0～60cm土层平均脱盐率(7.58%)减小,而60～120cm土层脱盐率(11.01%)增大。除20～40cm土层外,其他层含水量变异性均与灌前一致,说明含水量已接近灌前水平。至灌后第3周,各层含盐量、剖面平均盐分(中等变异性)及平均水分(弱变异性)含量的变异性未变,但其变异系数均在减小;剖面平均含水量的空间自相关性由中等转为强烈,变程一直增大,而平均含盐量均具有强烈的空间自相关性,变程先增大后减小。
The spatio-temporal variations of soil water and salt before and after irrigation in oasis farmland in Qitai County of Xinjiang were comparatively studied. The results showed that before irrigation, the soil moisture content of each layer was lower (18.43% ~ 20.30%) and showed medium (weak) variability. One week after flood irrigation, the soil water content in other layers became weak variability except for 40 ~ 60cm and 100 ~ 120cm soil layers. The average soil water content increased by 6.90% and the desalination rate reached 11.37% The soil moisture increase rate (50.93%) and desalination rate (27.14%) were the highest in 0-20 cm soil layer, and the lowest (26.59%) and desalination rate (-4.76%) in the bottom layer (100-120 cm). The water loss rate of the surface layer (0 ~ 20cm) was the highest (28.84%), the average desalination rate was 9.63% and the average desalination rate (7.58% ), While the desalination rate (11.01%) of 60 ~ 120cm soil layer increased. Except for 20 ~ 40cm soil layer, the variability of water content of other layers were consistent with that before irrigation, indicating that the water content was close to the level before irrigation. In the third week after irrigation, the variability of salt content, average salinity (medium variability) and average water (weak variability) in the layers did not change, but the coefficients of variation were all decreased. The average water content The spatial autocorrelation changed from medium to strong, the range of variation increased continuously, but the average salinity had a strong spatial autocorrelation, and the range of variation first increased and then decreased.