Influence factor analysis of soil heavy metal Cd based on the GeoDetector

As a variant with high spatial differentiation and continuous space time, soil is polluted by various artificial or natural factors, and the pollution of heavy metal Cd is one of the more serious problems. This study took Liaocheng, as the research area and sampled the points in a grid center of 10 km × 10 km to obtain the sampling data of heavy metal Cd in the soil surface layer at depths of 0–20 cm. We selected the environmental background value of Shandong Province as the standard and used the geological accumulation index method to evaluate the pollution status of heavy metal Cd in the experimental area, concluding that there was a moderate level of Cd pollution in the study area. On this basis, we selected soil pH value, soil sub-class, annual average precipitation, annual average surface temperature, elevation data, and change in GDP as the six major influencing factors of heavy metal Cd in the study area by GeoDetector analysis. The correlation between soil heavy metal Cd and the impact factors was explored. The results revealed that soil pH and elevation exerted a large influence on soil Cd content, while annual average surface temperature had the least influence. The interaction of various influencing factors on heavy metal Cd was nonlinearly enhanced, especially the elevation data and annual average precipitation data.