Mekong Delta has weak vulnerable geological structure, so any event in nature or human activities will have great influence on the land.
To serve socio-economic development, people are increasingly affecting nature, worsening erosion on rivers, canals and ditches. Landslides not only cause asset damages, but also threaten the life of millions of people living in these areas.
According to HCM City National University, since 2010, landslides on river and canal banks have become more serious. In 2010, only 99 landslide spots were found, while the figure increased by seven times to 681 by 2019.
Dr Huynh Cong Hoai from the HCM City National University said the Mekong Delta is young land formed by alluvial deposits from the Mekong River and coastal sediments. The area has weak ground and is very vulnerable to any impact of nature or humans.
|The increased number of landslides in the last 10 years is attributed to the construction of new infrastructure and houses near riverbanks, uncontrolled sand exploitation, and shortage of sediment due to the existence of a series of hydropower dams on the upper course.|
The increased number of landslides in the last 10 years is attributed to the construction of new infrastructure and houses near riverbanks, uncontrolled sand exploitation, and shortage of sediment due to the existence of a series of hydropower dams on the upper course.
According to the Southern Research Institute of Water Resources, An Giang and Dong Thap, the two provinces at the Tien and Hau Riverhead have the most serious landslides.
In An Giang, from 1970 to 2000, the landslide in Tan Chau district (now Tan Chau town) wiped out nearly 60 hectares of land and led to a combined 30 deaths and missing people.
In April 2017, at the junction of the Hau and Vam Nao rivers, 16 houses fell into the Hau river because of a landslide, while the My Hoi Dong - Nhon My inter-commune roads were interrupted. The disaster caused property damage worth VND 90 billion.
On August 1, 2019, also in An Giang, half of the surface of National Road 91 collapsed, causing hundreds of billions of dong of damage.
A study by the HCM City National University found that the landslide in Mekong Delta occurs in two forms – erosion and riverbank.
Erosion occurs to the surface of a riverbed or riverbank, while landslides occur when the river bank is unstable and slips downstream.
At present, the Tien and Hau river currents in Chau Doc city and Tan Chau town (An Giang province) have an average velocity of 1.6m/sec in flood season and 0.6m/sec in dry season. The Hau river section that runs across this area is likely to be eroded all year round.
Hoai said with the weak geological structure of the Mekong Delta, along with the unpredictable flow, constantly changing between seasons, riverbank erosion is inevitable.
Many provinces have been bracing for it following a forecast that the intrusion of seawater up rivers would be early and severe this year.
The Mekong River Commission (MRC) needs to take responsibility for the solutions to deal with the river's color change, according to Vu Trong Hong, former Deputy Minister of Agriculture and Rural Development.