Remote sensing images, field survey data, and historical monitoring data are collected to analyze the historical change trend and spatial variation rules of sediment quality of the Liaohe Estuary and further investigate the effects of sea-area utilization type and vegetation succession stage on the variation patterns of environmental elements in the sediments. The results showed that the quality of the sediments in the Liaohe Estuary is overall favorable, and the average contents of various elements all satisfy the quality standards of first-grade sediments. The nutritive elements in the sediments exhibit obvious zonal distribution patterns, while heavy metals are randomly distributed and exhibit no obvious patterns. The effect of sea-area utilization type on the enrichment of pollutants in the sediments exhibits certain significant differences, suggesting that the distributions of heavy metals and pollutants are subject to human activities and exhibit certain randomness. The main control factors are significantly different at different vegetation succession stages. Specifically, the vegetation distribution in the initial succession stage is mainly affected by salinity; with the transition from halophytic vegetation to terrestrial vegetation, the inherent correlation between vegetation distribution characteristics and the contents of total organic carbon, total nitrogen, and total phosphorus increase gradually. Meanwhile, the content of heavy-metal pollutants exhibits no significantly inherent correlation between the distributions of the plant community.
Keywords: sea area utilization type; sediments; temporal and spatial dynamic variation; the Liaohe Estuary; vegetation succession.