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运用小波变换和室内化学分析分析了微域尺度苏打盐渍土水盐空间和时间变化特征。结果表明:小波检测的突变点主要分布在洼地边缘,沿着土壤剖面方向主要集中在土壤表层(0~30cm)。结合室内分析表明,苏打盐渍化地区表现为盐化草甸土和苏打碱土镶嵌分布的微域格局,其中盐化草甸土分布在相对低洼的部位,苏打碱土分布在微坡地和高平地。通过小波检测表明,苏打盐渍土的盐分变化过程可以分为三个时段:雨季波动期,秋后返盐期和冻融聚盐期。微弱的淋溶下渗和强烈返盐的交替变化组成了非冻融季节苏打碱土表层的盐分变化规律。冻融季节,潜水可以影响到高平地的土壤(苏打碱土)表层的积盐。冻融积盐是松嫩平原碱化程度不断加剧的重要原因之一。
The characteristics of water and salt in space and time of sodic saline soil in micro-scale were analyzed by wavelet transform and indoor chemical analysis. The results show that the mutation points detected by wavelet transform are mainly located at the edge of depression, and are mainly concentrated in the soil surface (0 ~ 30cm) along the soil profile. According to the indoor analysis, the sodic salinization area shows the mosaic pattern of salinized meadow soil and soda ash, in which the salty meadow soil distributes in the relatively low-lying parts and the sodic soil distributes in the micro-slope land and the high ground. The results of wavelet analysis show that the salinity change of sodic saline soil can be divided into three periods: the fluctuating period of the rainy season, the salt return period in the autumn and the period of the frozen-thawed salt phase. The weak leaching infiltration and the strong return to the salt change constitute the non-freezing and thawing season soda ash surface salt changes. During the freeze-thaw season, diving can affect salt accumulation on the surface of the stilt soils (soda ash). Freezing-thawing salt accumulation is one of the important reasons for the increasing degree of alkalinization in Songnen Plain.