电磁感应仪用于土壤盐分空间变异及其剖面分布特征研究

运用电磁感应仪EM38,结合GIS技术和地统计方法对黄河三角洲地区典型地块0～40 cm与0～80 cm土层含盐量的空间变异性进行研究,并对研究区盐渍化分级以及盐分剖面分布特征进行探讨.结果表明:研究区各土层土壤盐分较高,均表现为中等变异强度,且研究区土壤盐分总体上呈一定的表聚趋势;各土层土壤盐分的半方差函数均较符合指数模型,都表现为强空间自相关性;气候、微地形、地下水等结构性因素是主导土壤盐分空间分布格局的直接因素.由盐渍化分级及盐分剖面特征分析结果可知:重度盐化土是研究区最主要的土壤类型,轻度盐化土分布面积最小;研究区主要盐分剖面类型为表聚性,其次分别为均匀型和底聚型;此外,盐分剖面类型的分布在一定程度上反映了植被类型以及土地利用方式.该研究结果为黄河三角洲地区盐渍化土壤的精准改良与科学管理提供了一定的理论基础和实践依据.

Study on spatial variability and profile distribution characteristics of soil salinity by Kriging with an electromagnetic induction

Electromagnetic induction EM38 was applied to study the spatial variability of soil salinity at soil layers of 0-40 cm and 0-80 cm with the help of GIS and geostatistics, which was performed in characteristic field of the Yellow River Delta, and salinization classification and salinity profile distribution characteristics were further analysed. The results showed that soil salinity at both soil layers were precious high and both exhibited moderate spatial variation, and soil salinity overall exhibited the trend of top enrichment in the study area. Exponential model was fitted to the semi-variograms of soil salinity at different soil layers, and both showed the strong spatial autocorrelation. Spatial distribution patterns of soil salinity were mainly controlled by structural factors, such as climate, micro-topography, groundwater and so on. Analysis on salinization classification and salinity profile characteristics indicated that heavy salinized soil was the predominant soil type in the study area, while the distribution area of light salinized soil was the least. The predominant salinity profile type was inverted salinity profiles, followed by uniform and normal salinity profiles, respectively. Furthermore, the distribution of salinity profile types reflected the vegetation types and land use patterns to a certain extent. The research results can serve as a theoretical and practical reference for the precise amelioration and scientific management of saline soils in the Yellow River Delta.