HẠ THẤP LÒNG DẪN VÀ NHỮNG TÁC ĐỘNG CỦA NÓ ĐẾN HỆ THỐNG SÔNG CỬU LONG

Abstract

Confront informing that river bed degradation and its impacts to river gradients will strongly impact to hydrodynamics regime and its river morphology in the Mekong Delta. This study elaborates and contributes for that message, it show that overload sand mining, upstream damming will strongly impact to stability of the Mekong Delta. From our two key approaches: 1) historical bed topography analysis; and 2) water level analysis, the results show trend of bed degradation from up to 3m/yr (Sa Dec in the period 2014÷2017) and low tide water level is reduced about 3÷10mm/yr at different locations. This impact counterpart with rate of land subsidence, sea level rise will push Mekong Delta into tidal stronger influenced which might will causes tidal flooding, higher flow velocity in canal system, stronger salinity intrusion, limitation of self –irrigate in higher regions and self-drainage for lower regions.