莱州湾南岸地区表层土壤盐分离子分异规律

SPATIAL DISTRIBUTION OF SALT IONS IN SURFACE SOILS IN THE SOUTH COAST OF LAIZHOU BAY

选取莱州湾南岸为典型研究区,系统采集了111个表层土壤样品,测试了土壤的K^+、Na^+、Ca^2+、Mg^2+、Cl^-、SO42-、HCO3^-、全盐量等8项指标,运用多元统计学和地统计学的方法,揭示了莱州湾南岸的表层土壤盐分离子之间的关系及空间分异规律。研究表明:莱州湾南岸表层土壤盐渍化程度为轻度盐渍化,非盐土占到总面积的51.7%,轻度及中度盐渍土占到总面积的34.3%,重度盐渍土及盐土分布在东北部沿海地区,面积约为148 km^2,占到总面积的14%,并且呈现集中分布态势,盐渍化强弱程度分布格局大致呈现从沿海到内陆逐渐减少的趋势。多元统计分析表明:Na^+与Cl^-、SO42-与Ca^2+、Mg^2+与Cl^-之间呈现显著正相关,Cl^-、Na^+为第1类,Ca^2+、SO42-、K^+、Mg^2+和HCO3^-为第2类,土壤中盐分离子表现出中等和强烈的空间变异,且盐分离子高值区与海咸水入侵位置基本一致。

This study is devoted to provision of a reference for the rational use of land in coastal saline soil areas.A total of 111 surficial samples were collected and measured for the K^+,Na^+,Ca^2+,Mg^2+,Cl^-,SO42-,HCO3^-,in addition to total salt content.Multivariate statistics and geostatistics were applied to seek for the spatial distribution pattern of surface soil salt segregants on the southern bank of Laizhou Bay.The results show that the salinity of surface sediments in the southern coast of Laizhou Bay is quite low.Non-salt soil accounts for 51.7%of the total area with 34.3%mildly and moderately polluted.Heavily salinized soil area occupies a total of 148 km2 which is mainly distributed in north-eastern coastal areas,accounting for 14%of the study area.Spatially,the distribution of salinization intensity decreases from coast to inland.Na^+and Cl^-,SO42-and Ca^2+,Mg^2+and Cl^-dominate,seconded by SO42-,K^+,Mg^2+and HCO3.Cl^-shows positive correlation with Na^+and Ca^2+.The salt content in soil has moderate and strong spatial variability.High-value regions are found in the areas often invaded by sea water.