Assessment of Water Resources and Salinity Intrusion in the Mekong Delta

Abstract

A methodology is presented for the assessment of water resources and salinity intrusion in the Mekong Delta in Vietnam. The flow and water salinity at different locations in the river network have been dynamically assessed by the developed three-step approach in which the hydrodynamic, advection-dispersion models, harmonic analysis, and regression techniques have been employed in the development of the relationships between the boundary conditions (upstream inflows and tides at river mouths) and the harmonic constituents of flow and water salinity. These relationships were subsequently used to determine the parameter values of harmonic constituents of flow and water salinity at specific locations under various hydrologic conditions and water allocation alternatives as needed for water management purpose. With known harmonic parameters, the flow and water salinity at the locations can be predicted by a harmonic analysis method and the river water available for agricultural use can then be determined. The advantage of this methodology is that the river water can be dynamically assessed without performing the hydrodynamic and advection-dispersion simulations in the water resources management process. Due to the limitation of data availability, a preliminary assessment of groundwater resources has been included. The results indicate that the use of groundwater as supplemental resources for agricultural production is possible

Keywords:

• Water resources assessment
• salinity intrusion
• hydrodynamic model
• advection-dispersion model
• harmonic analysis
• Mekong Delta