典型工矿区小流域土壤pH值空间分布特征及其影响因素

Spatial Distribution Characteristics and Factors Influencing Soil pH Values in Small Watershed in Typical Industrial and Mining Area

[目的]揭示南太行典型工矿区土壤pH值的空间分布规律及影响过程,为该典型工矿区复杂环境下土壤环境质量评估及污染防治提供科学支撑。[方法]以南太行典型工矿区蟒河小流域为研究区,采集121个土壤表层(0—20 cm)样品和部分辅助样品,综合应用3S技术、地统计学及地理探测器等模型方法,对研究区土壤表层pH值空间分布特征及影响因素展开研究。[结果]研究区土壤pH值范围在6.40~8.53之间,均值为7.82,低于黄河流域河南段背景值(背景值为8.46),与其他时期相比,土壤pH均值下降,存在土壤酸化趋势。土壤pH值呈弱空间变异,受地形等因素影响大,当间隔距离小于1905 m时,空间分布连续,具有较强空间自相关性。基于经验贝叶斯克里金的土壤pH值空间插值效果更优,土壤pH值空间上呈梯度分布,由中西部向东北和南部递增。低值区主要在中部和西部的河谷及山前平原地带;单个因子对pH值解释力不明显,坡向、土地利用等叠加其他因子后对流域内土壤pH值空间分布解释程度显著增强。[结论]自然条件及人类活动等多要素叠加作用是区域土壤pH值空间分布的主要驱动因素,也是区域土壤环境评估与污染修复重点关注的内容。

[Objective] The spatial distribution patterns and influencing processes of soil pH value in typical industrial and mining areas in the Southern Taihang Mountains were analyzed,to provide scientific support for soil environmental quality assessments and pollution prevention strategies in the complex environment of this area,comprising typical industrial and mining activities.[Methods] Studying the Manghe watershed in industrial and mining areas of the Southern Taihang Mountains,121 topsoil(0—20 cm) and auxiliary samples were collected.“3S” technology,geostatistics,geographical detectors,and other model methods were comprehensively applied to study the spatial distribution characteristics and factors influencing topsoil pH value in the research area.[Results] The soil pH value in the study area ranged from 6.40 to 8.53,with a mean value of 7.82,which was lower than the background value of the Henan section of the Yellow River basin(8.46).Compared with previous studies,the average soil pH value decreased,indicating a trend of soil acidification.Soil pH value showed weak spatial variation and was significantly influenced by factors such as terrain.When the interval distance between sites was less than 1 905 m,the spatial distribution was continuous and exhibited strong spatial autocorrelation.The spatial interpolation effect of soil pH value based on empirical Bayesian Kriging was better,and the spatial distribution of soil pH value showed an increasing gradient from the central and western regions to the northeast and south.Low-value areas were mainly located in the valleys and piedmont plains in the central and western regions.The explanatory power of individual factors on pH value was unclear;however,the superposition of slope direction,land use,and other factors significantly enhanced the explanation of the spatial distribution of soil pH value in the watershed.[Conclusion] The superposition of multiple factors,such as natural conditions and human activities,were the main drivers explaining the spatial distribution of regional soil pH value and should be the focus of regional soil environmental assessments and pollution remediation efforts.