ENSO Phase Shift and Weather Predictions
On May 10, 2024, during a national conference on disaster prevention and search and rescue, Hoang Duc Cuong, Deputy Director General of the Vietnam Meteorological and Hydrological Administration, shared that weather patterns this year show similarities to those of 2020, a year marked by devastating floods and landslides in Central Vietnam.
According to Cuong, ENSO (El Niño-Southern Oscillation), which measures changes in sea surface temperatures in the eastern equatorial and central Pacific Ocean, is currently in a neutral phase with a probability of 80-85%. From July to September, ENSO is expected to transition to a La Niña phase with a 60-65% probability, potentially continuing until the end of the year.
"This shift from El Niño to La Niña suggests that extreme weather events like droughts, floods, thunderstorms, and hail are likely to occur in Vietnam this year. The rainy season may start late, and storms and tropical depressions may appear in clusters during a short period," Cuong explained.
Forecast for Tropical Storms and Flooding
Meteorologists anticipate 11-13 tropical storms and depressions in the East Sea this year, with 5-7 making landfall in Vietnam. From now until early June, the likelihood of storms and depressions is low, while the latter half of the season, from September to November 2024, is likely to see increased activity.
Due to these storms and depressions, rainfall in the latter half of the year is predicted to be close to or exceed the average over many years. Heavy rainfall is particularly expected in Central Vietnam during the final months of the year.
Water levels in Central Vietnam and the Central Highlands are forecast to be similar to the historical average. However, flood peaks in 2024 are expected to reach alert levels of 1-2 in the lower basins of the Ma River (Thanh Hoa) and the Ca River (Nghe An, Ha Tinh). The lower basins of major rivers from Quang Binh to Quang Ngai, Binh Dinh, and Khanh Hoa are likely to reach alert levels of 2-3, while rivers in Phu Yen, Ninh Thuan, and Binh Thuan may surpass alert level 2 (with the highest being alert level 3).
Government Preparedness
In light of these predictions, Deputy Prime Minister Tran Luu Quang urged ministries and local governments to prepare for the shift from El Niño to La Niña. The meteorological agency was also instructed to enhance its forecasting capabilities to assist authorities in developing appropriate disaster prevention measures.
Devastating Impacts of 2020 Floods
In 2020, from October 11 to November 15, Central Vietnam was ravaged by eight storms, two tropical depressions, and heavy rainfall. Typhoon Molave, with winds of 11-12, made landfall in Quang Nam and Quang Ngai, bringing the strongest winds in 20 years.
Major rivers in Central Vietnam experienced rapid flooding, with the Hieu River in Dong Ha (Quang Tri) and the Bo River in Phu Oc (Thua Thien Hue) both surpassing their historical flood levels of 1999. Over 317,000 households with 1.2 million residents were affected by flooding across seven provinces from Nghe An to Quang Nam, with the peak occurring on October 12 and lasting for 15 days.
On October 12, a landslide from a 120-meter-high mountain buried the control room of the Rao Trang 3 Hydropower Plant in Phong Dien District, Thua Thien Hue Province, claiming the lives of 17 workers.
The 2020 natural disasters resulted in the deaths of 291 people, with 64 others missing. Landslides accounted for the most fatalities with 132, followed by floods with 108. Over 336,400 houses were damaged, requiring urgent evacuation. Agricultural losses included 198,300 hectares of rice and crops, while 52,000 livestock animals and 4.11 million poultry were killed or swept away.
The economic damage from these disasters exceeded 35,180 billion VND, seven times higher than in 2021 and nearly four times more than in 2023.