Red River is about to run out ... pink

Red river water is in danger of no longer pink. Research over the years has shown that the sediment content of this river is decreasing, causing unpredictable environmental changes.

>> Red river water through Yen Bai is contaminated with toxic lead
>> The culprit makes the Red River "sick"
>> Finding the cause of the Red River "sharpness"

Alluvial loss

Mr. Trinh Xuan Hoang, Institute of Water Resources Planning - Ministry of Agriculture and Rural Development said, the Red River is one of the rivers with a large amount of silt. However, the sediment load has decreased markedly after reservoirs not yet upstream such as Hoa Binh and Tuyen Quang.

During the period from 1988 to 2008, the average sediment content for many years in Son Tay on the Red River was only 45 million tons / year, ie, 38% of the total amount of sediment before the upstream reservoir. In Hanoi on the Red River, the total amount of suspended sediment averages only 38 million tons / year for many years, equal to 51% of the total amount of sediment before lakes.

' The monitoring and measurement data clearly show that the construction of large reservoirs upstream is the main reason for significantly reducing the sediment content to the downstream, ' said Mr. Hoang. But this sediment reduction phenomenon is not known by the naked eye. ' As long as you see the river in the eye, it is more dangerous for the Red River .'

Sediment on the Red River is decreasing. Photo: Viet Hung.

The hydroelectric dams must be redesigned

According to Dr. Dao Trong Tu, former Deputy Secretary General of Vietnam Rivers Network, it is fortunate for residents of the Red River Delta that alluvium does not play a prerequisite for agriculture as in the Mekong Delta.

In the Mekong Delta, silt is of good quality. Farmers who put sediment into the field will be able to support a significant amount of fertilizer. The silt in the Red River does not say anything about water quality. Residents along the river also do not use silt instead of fertilizer.

However, the harm is that shrimp fish are living in turbid water environment for many years, now changed to clear water, inevitably there will be unforeseen changes. In addition, alluvial soil with specific nutrient components is now lost, will change many other links. The ecological balance on the river will be broken.

Dr. Dao Trong Tu warns that if there are no timely solutions from now, the Red River will fall into the situation like the current Mekong: Less silt, less fish, less fishermen's life.

This also leads to disruption of ecological balance, resulting in unpredictable environmental consequences.

According to scientists, the hydropower plants now have a blowdown, but they cannot be fully discharged. A significant amount of sediment is still blocked. Up to now, no measures or works have helped to restore the silt to the Red River and other rivers.

'Only the way to salvage alluvial drains for the Red River is by redesigning the blowdown gates of hydropower projects , ' said Mr. Hoang.

Difficulties are that the monitoring data on river sediment in Vietnam are lacking and fragmented.MARD has only 6 measurement stations on the border, only once a month. Therefore, there is a lack of regular and continuous data on alluvial Red River as well as other rivers.

According to Mr. Hoang, the whole impact of hydropower plants from downstream to upstream needs to be assessed. The scope of the program must be broader to determine the impact of these dams.

In addition, it is necessary to install additional automatic measuring stations, continuously measure river sediment and other criteria for river water quality. Based on the results of measurement, evaluation, it will find the cause, from which there are technical and construction interventions.