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Hydrologic dynamics, sewage and industries determine the distribution and migration pathways of heavy metals in the natural environments including soils across the urbanized area. In this study, 323 stratified soil samples from a brownfield in Jiangsu Province, China, were collected to assess the heavy metals (Cu, Ni, Pb, Cd, As and Hg) contaminations. Contamination factor (Cfi), Nemerow pollution index (PIN) and enrichment factor (EFi) were evaluated to assess the heavy metal pollution, while sources of pollution were identified in combination with geo‐statistical, correlations and principal components analysis. Moreover, transport of Ni in soil profiles over the next 30 years was simulated using HYDRUS. The vertical distribution revealed that the soil surface (0–10 cm) had the highest concentration of heavy metal contamination. ICP‐MS measurements showed that the soil in the brownfield was enriched with Cu, Ni, Pb, Cd, As and Hg, where Ni was the most severe and prevalent contaminant. The results of source apportionment analysis showed that Ni, Cd, Pb and Cu were mainly derived from building materials and sewage discharge, while As and Hg may come from fossil fuel combustion and agricultural discharges from upstream river catchment. The migration of Ni was largely driven by the combination of hydrological variability including the flow and solute contaminant gradients in soils. Our work highlights the need for a comprehensive understanding of the complexity of hydrology, and sewage discharge in heavy metal dynamics and migration pathways in China's brownfield soil at regional and national scales. [ABSTRACT FROM AUTHOR]

The ocean is the ultimate sink for all pollutants, rivers are important channels for land-based pollutants to enter the oceans. Riverine transport of polycyclic aromatic hydrocarbons (PAHs) to coastal seas in China poses environmental threats. This study examined the spatial and temporal distribution of PAHs in coastal rivers in Yancheng City in Jiangsu Province of China, with the aim of identifying their likely sources, concentrations, and influencing factors. Surface sediments were taken from the Xinyanggang River (XYR) and the Sheyang River (SYR). The concentrations of Ʃ 16 PAHs in river sediments were measured on average 477.05 ng/g dry weight (dw), with values varying from 2.18 to 6351.42 ng/g, indicating a moderate pollution level, with a dominance of high molecular weight (HMW) PAHs. The XYR exhibited significantly higher PAHs concentrations compared to the SYR. The key sources of PAHs were vehicle emissions (47.87%), coal and natural gas combustion (35.07%). Geographically weighted regression and redundancy analysis linked PAHs pollution to distinct land use patterns and socioeconomic indicators, highlighting urban land as the major contributor, driven by high urbanization and industrialization (70.91%). In XYR, industrial activities and transport emissions were major contributors, while in SYR, agricultural activities predominantly influenced PAHs pollution. Urgent mitigation strategies are needed to reduce PAHs pollution in river sediments, mitigating ecological and human risks associated with these contaminants. [Display omitted] • Xinyanggang River was noticed to be the hotspots of PAHs pollution. • Vehicle emissions are the key sources of PAHs pollution in the river sediment. • Urban land strongly correlates with PAHs pollution then agriculture land. • Mitigations strategies and urgent policies are needed to reduce the PAHs pollution. [ABSTRACT FROM AUTHOR]

• A coupled model "SWOT-AHP" was proposed to evaluate the social sustainability. • Growth-oriented strategy given priority for the strategy of concentrated residence of farmers. • Identified and discussed robust policies for sustainable rural development. • Findings of this study will be helpful in achieving the targets of SDGs- 1, 8, 11. The concentrated living of farmers is an important engine for rural revitalization and a new type of urbanization, thus is of great significance for the construction of a resource-saving society. Due to rapid economic development in China, some farmers have successfully urbanized through rural–urban migration, but still more than 500 million farmers, have not migrated yet. Concentrated residence has long been recognized as the best strategy to help Chinese farmers to achieve local urbanization, and has been paid much attention in the local, regional, national and global scientific community. Although robust models and policies are still lagging behind because of insufficient datasets and models. In this study, empirical model has been used in which concentrated residence cases of farmers in Yancheng City, Jiangsu Province of China taken as a case study, and strength (S), weakness (W), opportunities (O) and threats (T) as the criterion layer to identify 16 influencing factors as the index layer. For this study, data was collected during 2021 & 2022 by questioner-based survey from 6 different settlements, and AHP analytic hierarchy model integrated with SWOT was used to built farmers' concentrated residence strategies. The positioning coordinates of this study show the following weightage like S (0.480, 0), W (-0.098, 0), O (0, 0.306), and T (0, −0.116) which clearly mentions that S and O as positive influences, W and T as negative influences, and locates the respective total weights. Therefore, empirical results indicate that SO (growth-oriented) strategy should be emphasized to build robust strategies for concentrated residence of farmers. The findings of this study can provide a benign model for centralized residence for local governments, village collectives, and farmers withdrawing from homestead, and help to promote the sustainable development of society. [ABSTRACT FROM AUTHOR]