## 3 Results and Discussion
### Evaluation of Soil Heavy Metal Pollution and Ecological Risk
This processing enhances the intuitiveness of data analysis. As illustrated in Figure 2, the spatial distribution of Cd, Pb, Zn, Ni, Mn, and V in the study area is notably complex, with varying degrees of high-value regions present throughout most of the area. The spatial distributions of Cd, Pb, and V exhibit similarities, with numerous high-value ranges across the entire study area. Although the mean value relative to the background exceedance factor for Pb did not exceed 1, the overall concentration in the study area is relatively high. In contrast, the spatial distributions of Cr, Cu, and Co are more uniform, with a distinct elevation in concentration observed in the central region compared to the eastern and western directions, potentially linked to the spatial distribution of key enterprises. The spatial distribution of As, Hg, and Se demonstrates clear regional patterns, generally exhibiting low concentration levels, while high-concentration point distributions are observed in the central-western, southern, and northwestern regions. Overall, despite the differing distribution patterns of the heavy metals, their spatial distributions are closely related to human activities. To visually present the pollution status of different heavy metals in the soil, the \(I_{geo}\) evaluation results for the study area are depicted as a boxplot. As can be seen from Figure 3, the pollution levels of eight heavy metals, including Cd, As, Hg, Pb, Zn, Ni, V, and Co, are relatively low, with more than 75% of the sampling points considered to be uncontaminated. The remaining heavy metals, Cr, Cu, and Mn, exhibit a broader range of pollution levels, all falling within the light to moderate pollution category. However, due to the varying degrees of toxicity caused by different heavy metals, it cannot be denied that the presence of excessively high outlier values for highly toxic heavy metals such as Hg poses significant ecological pollution hazards. Therefore, it is necessary to assess the ecological hazards of heavy metals in the soil. Figure 4 shows that the ecological risk posed by the pollution of seven heavy metals, with the exception of Cd, As, Cu, and Hg, is minor. The ecological risk assessment for soil heavy metal pollution by Cd ranges from minor to moderate levels. For As, some outlier sites indicate a strong ecological risk. In the case of Cu, certain outlier sites suggest a moderate ecological risk due to heavy metal pollution. For Hg, the presence of extreme values in the ecological risk assessment points to a very strong level of ecological risk. Figure 3: Boxplot of the evaluation results of the \(I_{geo}\). The preliminary inference suggests that the distribution characteristics of heavy metal concentrations in the study area are closely related to human activities. Additionally, the Poyang Lake area is a significant agricultural production region, and the distribution characteristics of soil heavy metals may also be influenced by agricultural practices and daily living activities. To explore the extent of the impact of different types of human activities on these distribution characteristics, it is essential to analyze the distribution patterns of key polluting enterprises in the study area alongside land use types. The comprehensive potential ecological risk index for the study area was subjected to IDW interpolation. The results, combined with the spatial distribution characteristics of key polluting enterprises, are presented in Figure 5. The four color blocks in Figure 5 are divided according to the degree of ecological risk, for details see Table 1, and the key enterprises are publicly disclosed on the official website of the study area's Ecological Environment Bureau. Figure 5 indicates that the _RI_ values in the study area exhibit a spatial distribution pattern of higher values in the central region and lower values on the peripheries. Specifically, the central-western and central-southern areas contain two zones classified as having very strong ecological risk.