Topography modelling for potentially leaked CO2 diffusion and its application in human health risk assessment for carbon capture, utilisation, and storage engineering in China

•Mainstream software is coupled sequentially to study the CO2 dispersions.•Adverse health effects and safety regulatory are used to establish the risk levels.•Evaluation of human exposure risk for leaked CO2 in CCUS over complex terrain.•Safety spatial boundaries is characterized with a high level of visualization.•The first study of spatiotemporal diffusion and risk of trace leakage in CCUS area.