Assessing potential environmental exposure from chemical incidents in coastal Southeast Vietnam using remote sensing and mathematical modelling

The coastal area of Southeast Vietnam is one of the most dynamic regions with rapid development and diverse natural resources. However, it also has a high potential for environmental hazards resulting from chemical incidents during its development process, particularly from industrial zones. In this study, potential environmental exposure resulting from chemical incidents in the coastal region of Southeast Vietnam is analyzed using a combination of remote sensing methods, mathematical modeling, GIS techniques, and index methods. Based on the results of the hazard classification of environmental incidents in the Southeast region, which have been conducted in previous studies by the author group, this study developed typical environmental incident scenarios and simulates the potential environmental exposure level of coastal areas in the event of an environmental incident using the mathematical model MIKE 21. The simulated result values are converted based on the rating scale to determine the Exposure Index and divided into four levels: low, moderate, high, and very high. The simulation and assessment results show that the potential pollution transmission range is lower during the dry season than during the rainy season and is mainly concentrated around the incident area. Of the 27 coastal sub-regions in the study area, 12/27 sub-regions were exposed during the dry season, accounting for 44.44%, and 15–16/27 sub-regions were exposed during the rainy season for 55.56–59.26%. The results of exposure zoning show that the risk of environmental exposure to coastal chemical incidents in the study area is relatively serious and has a wide-ranging impact if there are no timely and effective response measures. These assessment results are expected to contribute to increasing predictability and reducing potential consequences in the event of environmental incidents in the coastal areas of the Southeast region.