Development of an integrated tool responding to accidental oil spills in riverine and shoreline areas of Ho Chi Minh City, Vietnam

Abstract

Setting up contingency planning strategies for spilled oil is always a challenging and difficult task for environmental management and decision-making. A large number of riverine systems and large ports (approximately 42) make Ho Chi Minh City, the most important economic hub of Vietnam, vulnerable to oil spills. There is, however, no reliable tool to identify the vulnerability of biological and human-use resources to oil spills along Ho Chi Minh City's riverine systems and coastal areas. The objective of this study is to develop an integrated tool combining the Environmental Sensitivity Index with a numerical model. Wherein, the Environmental Sensitivity Index (ESI) is developed according to the guidelines of the National Oceanic and Atmospheric Administration (NOAA); and the MIKE 21 model is used as a simulation tool after careful calibration and validation against observation data. Based on the knowledge of accidental spillage that occurred in the past, four typical scenarios of the oil spill are proposed to estimate the spread of spilled oil in regards to volume, locations, oil types, and time of occurrence. This study revealed that the oil spread and dispersion are strongly affected by the flow regimes; and the fate of oil spills has severe impacts on the environmental system and biological resources along the river systems and coastal areas; particularly on the rich biodiversity of the Mangrove Biosphere Reserve established by UNESCO of Ho Chi Minh City. The results obtained from this study can provide the underlying knowledge to prepare an effective contingency plan to mitigate and respond to the adverse effects of spilled oil on the local natural environment and socioeconomics of the study region.