连云港徐圩新区盐渍土盐分时空分布特征及其主要影响因素分析

Characteristics of Temporal and Spatial Distribution of Salinity in Saline Soil and Its Main Influencing Factors in Xuwei New District of Lianyungang

调查分析土壤盐分的时空分布规律和变异特征,对于揭示土壤盐渍化成因、制定盐渍土改良方案、提升土地质量具有重要意义。以江苏沿海典型盐渍土分布区——连云港市徐圩新区作为研究区,应用地统计学与GIS相结合的方法,开展了研究区土壤盐分的空间分布特征研究,并基于长序列土壤水分和盐分的原位监测数据,分析了研究区土壤水盐的动态运移规律,在此基础上综合分析了影响研究区土壤盐分时空分布的主要环境因素。结果表明:随着土壤盐分含量的变化,区内土壤盐分中离子组成呈现出规律性变化特征,NaCl是土壤盐分的主要存在形式;研究区各层位土壤盐分均表现出中等程度的空间自相关性,其空间分布受随机因素和结构性因素的共同影响;研究区土壤盐分总体呈现出"东高西低"的水平向分布格局,在垂向分布上土壤盐分剖面特征表现出底聚型和表聚型两种主要类型;研究区表层土壤盐分呈现出明显的季节性变化特征,土壤脱盐-积盐过程交替发生;海岸线变迁、地下水埋深与TDS值、土地利用方式的差异是影响研究区土壤盐分空间分布的主要环境因素,气象因素是影响研究区表层土壤盐分年内动态变化的直接环境因素。

Investigation and analysis of the temporal and spatial distribution of soil salinity and variation characteristics are of great significance for revealing the causes of soil salinization,formulating saline soil improvement plans,and improving land quality.This study selects Xuwei New District of Lianyungang City,a typical saline soil distribution area along the coast of Jiangsu Province,as the research area.The study explores the spatial distribution and variation characteristics of soil salt in the study area by using the method of geostatistics and GIS.Meanwhile,the study analyzes the dynamic movement law of soil water and salt based on the long-term dynamic monitoring of soil water and salt,and comprehensively analyzes the main factors affecting the temporal and spatial distribution of saline soil salinity on this basis.The results show that with the change of soil salt content,the ion composition of soil salt shows a regular change,and NaCl is the main form of soil salt.The soil salinity of each layer in the study area shows a moderate degree of spatial autocorrelation,and its spatial distribution is affected by both random and structural factors;the overall soil salinity shows a horizontal distribution pattern of"high in the east and low in the west".In the vertical distribution,soil salinity exhibits two main types of salt profile characteristics:bottom accumulation type and surface accumulation type.The surface soil salinity in the study area shows obvious seasonal changes,and the process of soil desalination and salt accumulation occur alternately.Coastline changes,groundwater depth,TDS,and land use differences are the main environmental factors that affect the spatial distribution of soil salt in the study area.Meteorological factors are the direct environmental factors that affect the dynamic changes of surface soil salt in the study area.