基于地理探测器的寻乌县土壤微量元素影响因子分析

Influence Factors Analysis of Soil Trace Elements in Xunwu County Based on the Geographical Detector

为了对江西省赣州市寻乌县土壤硼(B)、硒(Se)、锰(Mn)、铜(Cu)4种微量元素的空间分布特征进行探究,同时分析影响其分布的因子,基于寻乌县2018年采集的572个表层土壤(0~20 cm)样点数据,采用描述性统计分析、相关性分析、地统计分析、地理探测器等方法进行分析。结果表明,根据《土地质量地球化学评价规范》划分标准,寻乌县4种微量元素中,土壤全量Se含量处于适中或较高的水平,不存在缺乏和过剩的情况,而土壤全量B、Mn和Cu含量处于较缺乏或缺乏的水平;由半方差函数分析的结果来看,B、Se、Mn、Cu的块金效应依次为11.82%、35.27%、49.75%和17.46%,表明4种微量元素中,B和Cu表现出较强的空间变异程度,而Se和Mn则为中等程度的空间变异。地理探测器的结果表明,重金属元素砷(As)含量、高程、土壤亚类和土属、成土母质对4种微量元素均有显著影响(P<0.05),其中As含量和土属对4种微量元素的解释能力较强,是影响寻乌县4种微量元素的主要因子;土壤重金属元素As含量、土地利用类型、植被覆盖度、植被类型以及土属、成土母质等成土因子均与坡度、坡向等地形因子有着非线性增强的交互作用。本研究结果为调节寻乌县土壤微量元素含量提供了理论支撑。

Based on the data of the 572 soil samples collected from the surface layer(0 ~ 20 cm) in Xunwu County in 2018, descriptive statistical analysis, correlation analysis, geostatistical analysis and geographic detectors were applied to analyze spatial differentiation of soil B, Se, Mn and Cu in distribution and its influencing factors in Xunwu County, Ganzhou city, Jiangxi province. According to the "Specification of land quality geochemical assessment", there was no deficiency or excess of soil total Se, but the contents of soil total B, Mn and Cu in the soil were slightly deficient or deficient;Semi-variogram function analysis showed that the soil B, Se, Mn and Cu of the nugget effect were 11.82%, 35.27%, 49.75% and 17.46%, which showed the soil B and Cu had strong spatial variation, while the soil Se and Mn had moderate spatial variation. Geographical detectors analysis showed that the contents of heavy metal element As, elevation, subclass, soil genus and parent material had significant impacts on the spatial variability of four soil trace elements(P<0.05), therein the contents of heavy metal element As and soil genus were the main factors affecting the four trace elements in Xunwu County;the contents of heavy metal element As, land use type, vegetation coverage, vegetation type, soil genus, parent material and other soil-forming factors had non-linear interaction with slope, aspect and other terrain factors. The results can provide theoretical support for the regulation of soil trace elements in Xunwu County.