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采用大田试验与室内分析相结合的方式研究了冻融期气温、土壤温度及盐分间的相互作用关系。结果表明:外界气温对冻融期土壤温度的影响随深度的增加而减弱;土壤消融前,地温随深度呈现递增趋势,土壤消融后,地温呈现随深度增大而减小的趋势;冻融期相邻两土层间地温在0.01的置信水平下保持极显著相关性,其决定系数均在0.8以上,且随深度的增加,各土层地温的相关性减弱;试验区土壤冻融期长达120 d左右,最大冻土深度约为80 cm,至3月上旬土壤完全解冻;整个冻融期可分为冻结带发育阶段、稳定冻结阶段及消融三个阶段,且此三阶段地温与土层深度间关系均可用公式精确拟合;冻融期土壤剖面盐分呈现随深度增加先增大后减小的趋势;处于冻结带中的土壤盐分保持0.3%以内的较低水平,属于非盐化土;80~120 cm深度存在稳定积盐层,且其盐分值基本表现出中度及重度盐化土的特征。
Field experiments and laboratory analysis were used to study the relationship between air temperature during freezing and thawing, soil temperature and salinity. The results showed that the influence of external air temperature on soil temperature during freezing and thawing periods decreased with increasing depth. Before soil ablation, the ground temperature showed an increasing trend with depth. After soil ablation, the ground temperature showed a decreasing trend as the depth increased. The soil temperature between two adjacent soil layers maintained a very significant correlation at the confidence level of 0.01 with a coefficient of determination above 0.8. With the increase of depth, the correlation of the soil temperature decreased. The soil freeze-thaw period in the experimental area was up to 120 d, the maximum depth of frozen soil is about 80 cm, and the soil is completely thawed in early March. The whole freeze-thaw period can be divided into three stages: the development stage of freezing zone, the stable freezing stage and the ablation stage. The relationship between depth and depth can be accurately fitted by the formula; the salt content of soil profile firstly increases and then decreases with the increase of depth; the soil salinity in the frozen zone keeps a relatively low level within 0.3% ; There is a stable salt layer in the depth of 80-120 cm, and its salinity value basically shows the characteristics of medium and heavy saline soil.