886 / 2024-09-19 18:21:53

Effects of land use on the distribution of heavy metals in surface water of the Nandu river, Hainan Island

heavy metals, surface water, Nandu River, land use

In recent decades, the areas along the Nandu river on Hainan Island are experiencing rapid land-use conversion, however effects of land use on the heavy metal pollution in the river still are not clear. In order to determine the impact of land use/cover on the heavy metal (Cd, Zn, Sb, Pb, Cr, Cu, As, and Hg) content in the water of Nandu River and assess the pollution status, surface water samples were collected from 37 representative sites along the Nandu River in August 2023 (wet season) and December 2023 (dry season), respectively. Our results showed that heavy metal concentration in surface water in the wet season was significantly higher than that in the dry season. Redundancy analysis (RDA) suggested that heavy metal concentrations in the surface water exhibited a significant correlation with construction land and farmland. On a seasonal scale, the land-use pattern showed more association with heavy metal contents of river water in the wet season, compared to that in the dry season. These findings contribute to sustainable land-use development and multi-scale landscape optimization to improve water quality in the Nandu River.