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Sand mining in the Mekong Delta revisited – current scales of local sediment deficits

Nature.com

Abstract

The delta of the Mekong River in Vietnam has been heavily impacted by anthropogenic stresses in recent years, such as upstream dam construction and sand mining within the main and distributary channels, leading to riverbank and coastal erosion. Intensive bathymetric surveys, conducted within the Tien River branch during the dry and wet season 2018, reveal a high magnitude of sand mining activities. For the year 2018, an analysis of bathymetric maps and the local refilling processes leads to an estimated sand extraction volume of 4.64 ±± 0.31 Mm33/yr in the study area, which covered around 20 km. Reported statistics of sand mining for all of the Mekong’s channels within the delta, which have a cumulative length of several hundred kilometres, are 17.77 Mm33/yr for this period. Results from this study highlight that these statistics are likely too conservative. It is also shown that natural sediment supplies from upper reaches of the Mekong are insufficient to compensate for the loss of extracted bed aggregates, illustrating the non-sustainable nature of the local sand mining practices.

Introduction

Anthropogenic stresses, such as groundwater extraction, river training, construction and operation of hydropower infrastructure as well as sand mining play an important role in the future evolution of the world’s largest river deltas1, https://doi.org/10.1038/516031a Tiếp tục đọc “Sand mining in the Mekong Delta revisited – current scales of local sediment deficits”

Did Vietnam Just Doom the Mekong?

thediplomat.com 

A policy reversal on Mekong dams has put Hanoi’s credibility – and the river’s fate – on the line

The recent decision by a Vietnamese oil company, Petrovietnam, to invest in a huge dam close to the much-loved World Heritage Site in Luang Prabang, Laos, has caused confusion and dismay for many Mekong experts, civil society groups, and some government officials in Hanoi.

A cascade of dam projects on the Lower Mekong in Laos has triggered consistent expressions of critical concern from Vietnam, with its delta highly vulnerable to such dams’ damaging downstream impacts. Back in 2011, the former Vietnamese prime minister publicly called for all construction to stop on the Xayaburi dam. Vietnam has also called upon Laos to rethink all subsequent dams.
Tiếp tục đọc “Did Vietnam Just Doom the Mekong?”