[Analysis of the Influencing Factors and Sources of Spatial Differentiation of Heavy Metals in Surface Sediments of the Shaanxi Section of the Yellow River].

To investigate the spatial distribution and sources of heavy metal contamination in the surface sediments of the Yellow River， this study focused on the Shaanxi section of the river. Sediment samples were collected from 54 locations， and the quantities of nine heavy metals， Cu， Fe， Mn， Ni， Zn， Cd， Cr， Pb， and As， were measured. The results revealed that the average values of heavy metal content were ranked as follows： Fe>Mn>Zn>Cr>As>Ni>Pb>Cu>Cd. Among these， Zn， Pb， Cd， and As exceeded shale background values， with Cd showing a high coefficient of variation， and 42.5% of the samples had Cd content above the background level. Notably， the content of As was above background levels in 90% of the samples. In contrast， the levels of the other heavy metals remained within acceptable risk thresholds. Spatial distribution analysis indicated that the primary factors influencing heavy metal content included population density， pH， and salt content. These factors interacted in ways that enhanced their combined effects， contributing to complex environmental conditions that may exacerbate regional ecological risks. Risk area delineation identified Wubao County， Hancheng City， Huayin City， Dali County， Heyang County， and Tongguan County as the main pollution hotspots. Using methods such as correlation analysis， principal component analysis， and receptor modeling， pollution source analysis indicated distinct sources for the various heavy metals. Cu， Fe， Mn， and Cr were predominantly of natural origin， while Ni was derived from a combination of natural and anthropogenic sources. The primary source of Cd was of agricultural origin， whereas Zn， Pb， and As were more influenced by anthropogenic activities. The predominant sources of heavy metals in the surface sediments of the study area included natural sources， agricultural sources， industrial sources， transportation sources， and composite pollution sources of unknown origin.