Forecasting saline intrusion under the influence of the northeast monsoon in the Mekong Delta

Abstract

Saline intrusion is one of the most frequently occurring natural disasters in a coastal area, posing the most serious impact in the Vietnamese Mekong Delta (MD). With the characteristics of the region as an open and low system, located at the end of the Mekong River basin and part of the Vam Co River system, this region is strongly affected by the tidal regime, and therefore saline intrusion is a feature of the region and has become familiar to the people living here in the dry season. The degree of deep penetration into the inland area depends on several factors. These factors contribute to the determination of the depth of salinity penetration into the MD. Therefore, the paper will focus on the 3 factors having the greatest impacts on the salinity penetration, including the influence of upstream flow, high tide, and the northeast monsoon season in the application of a combined assessment model to forecast saline intrusion in 2021 in the Mekong Delta. The reliability of the salinity propagation module is greater than 0.7%, based on the data series observed and calculated daily for 3 months during the dry season. The location of the measuring stations from the estuary to the inland field is about 20-50 km, showing a suitable range to calculate the salinity forecast to support livelihood models in the Mekong River.