The 24th IAHR-APD Congress (24th IAHR-APD Congress)

75 / 2023-12-31 00:11:48

PROPOSED CONSTRUCTION MEASURES FOR ADAPTING TO SALINITY INTRUSION IN MEKONG ESTUARIES

Salinity intrusion, Vietnamese Mekong Delta, submerged dikes, salinity adaptation.

The Vietnamese Mekong Delta (VMD) has played a pivotal role in Vietnam's development, contributing significantly by providing up to 50 percent of rice and 70 percent of aquaculture production. Salinity intrusion into the delta estuary has reduced agricultural productivity and caused freshwater shortages during the dry season. Changes in upstream flow, riverbed incision, rising sea level, and tidal fluctuations contribute to salinity intrusion extending more than 80 km inland, affecting 40 percent of the Mekong Delta. Therefore, research measures to mitigate or adapt to drought and saltwater intrusion in the VMD are significant.



Early warning measures, building salinity zoning maps, and changing land use with highly saline-adapted plants have been proposed. However, the study emphasizes the construction measures of barriers or submerged dikes as a solution to prevent salinity intrusion. This solution is proposed after analyzing field-measured data on the evolution of velocity distribution at two river cross-sections during a tidal cycle. Combine the numerical models to analyze changes in intrusion length for two scenarios – before and after the dike is installed – and consider closed and open submerged dikes scenarios.