机构地区:[1]中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011 [2]中国科学院研究生院,北京100049 [3]北京联合大学应用文理学院,北京100083 [4]新疆大学资源与环境科学学院,新疆乌鲁木齐830046 [5]中国科学院南京土壤研究所,江苏南京210008
出 处:《中国沙漠》2012年第5期1369-1378,共10页Journal of Desert Research
基 金:国家自然科学基金项目(41171165);北京市属高等学校人才强教计划资助项目(PHR200906125)共同资助
摘 要: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 paper studied the spatial and temporal variability of soil water content and soil salinity content in farmland before and after irrigation in Qitai County, Xinjiang, China. Before irrigation, the soil water content at each soil layer was low (18.43% -20.30% ) with moderate and weak variability. One week after irrigation, the spatial pattern of soil water content turned to be weak variability except for 40-60 cm and 100-120 cm soil layers; the average soil water content at the whole soil layer increased by 6.90% with an average desalination rate of 11.37 % ; the soil water content increasing rate (50.93%) and the desalination rate (27.14%) at the surface soil (0-20 cm) were the maximum, and the soil water content increasing rate (26.59%) and desalination rate (-4.76%) at the soil bottom layer (100-120 cm) were the minimum. Three weeks after irrigation, the average soil water content at the whole soil layer reduced by 3.64 %, and the soil water loss rate (28.84%) at the soil surface layer (0-20 cm) was the maximum; the average desalination rate at the whole soil layer was 9.63%, and the average desalination rate at 0-60 cm soil layer (7.58%) decreased while the desalination rate at 60-120 cm soil layer (11.01% ) increased. Apart from the 20-40 cm soil layer, the variability of soil water content distribution was consistent with that before irrigation, showing the similar soil water content. The variability of soil salinity content distribution at each soil layer, the average soil salinity (medium variance) and soil water content (weak variance) at the whole soil layer remained unchanged in three weeks after irrigation, while their variation coefficient decreased. The spatial autocorrelation of average soil water content at the whole soil layer transferred from moderate to strong, and its variable range was increasing; the average soil salinity content at the whole soil layer presented a strong spatial autocorrelation with the variable range increasing first an
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