'Unprecedented' floods in Central Vietnam will become 'new normal' in the future

PV: Sir,The flood lasted for many daysThe floods in the Central region have left more than 130 people dead and missing. Many people say that "these are unprecedented heavy rains." Can you assess this year's floods?

The cause of very heavy rain in the North Central region in general and Nghe An, Ha Tinh in particular in the past week is due to the influence of typical heavy rain-causing formations. That is the combination of convergence zones with storms/tropical low pressure (ATND) combined with cold air and the northeast wind-blocking terrain of the region, causing a very heavy rain and especially heavy rain in Ha Tinh province. Specifically, in just nearly 2 weeks, the Central region has received 2 consecutive cold air waves. In addition, the eastern slope of the Truong Son range also receives a northeast monsoon bringing moisture from the highlands to the mainland.

These are two very typical weather patterns that cause heavy rain in the Central region every year. This year, these patterns appeared at the same time, in succession, forming an extreme weather combination that caused large amounts of rain and floods to appear and last for many days. The rainfall measured from October 16 to 1:00 p.m. on October 20 in Nghe An was generally 150 - 350mm, higher in some places such as TV (hydrology) Cho Trang 483mm, KT (meteorology) Vinh 482mm, TV Con Cuong 388mm; in Ha Tinh, it was generally 500 - 800mm, higher in some places such as: KT Ha Tinh 1,401mm (rainfall reached 820mm/24h, setting a record for rainfall in the North Central region), TV Thach Dong 1,204mm, TV Cam Nhuong 996mm...

Historic floods in recent days have caused significant damage to the Central region. Photo: Hong Linh

In the first 20 days of October, provinces from Ha Tinh to Quang Ngai recorded rainfall of 1,000 - 2,000 mm, with some places recording rainfall of 2,000 - 3,000 mm. This figure is 3-5 times higher than the average rainfall of many years during the same period.

PV: In the coming time, what will the weather be like in Nghe An in particular and the Central region in general, sir?

Currently, there is storm No. 8 (international name Saudel) in the East Sea. On the morning of October 25, the storm is about 260 km east of the mainland provinces from Ha Tinh to Quang Tri. The strongest wind near the storm's center is level 8-9 (60-90 km/h), gusting to level 11. The radius of strong winds from level 6, gusting to level 8 or higher is about 140 km from the storm's center.

It is forecasted that in the next 24 hours, the storm will move westward at 15-20km per hour, making landfall in the provinces from Ha Tinh to Quang Tri and gradually weakening into a tropical depression, then a low pressure area. At 7:00 a.m. on October 26, the center of the low pressure area was at about 17.5 degrees North latitude; 105.2 degrees East longitude, in the southern Laos region.

It is forecasted that from now until the end of 2020, there will be about 4-6 storms and tropical depressions in the East Sea, of which about 2-4 will directly affect the mainland of our country, concentrated in the Central and Southern regions. Therefore, it is necessary to be on guard against heavy and prolonged rains in the Central region in the second half of October and November 2020, in the North Central region.

Mr. Nguyen Xuan Tien - Deputy Director of the North Central Hydrometeorological Station. Photo: PV

Severe cold spells may appear earlier than average, from the second half of December 2020 to February 2021, and may last from 7-10 days, with mountainous provinces lasting more than 10 days. Beware of frost and frost during the main months of winter 2020-2021.

Reporter: International experts say that flooding in the Central region is the result of complex weather patterns that could become the "new normal" in the future. As sea levels rise and move further inland, flood waters will be higher than before. And Vietnam is suffering the worst weather impacts in the world. Can you share your views on these comments?

I agree with the comments of international experts that floods in the Central region are the result of complex weather patterns, which may become the "new normal" in the future.Under the impact of climate changewill cause sea levels to rise, making it difficult for flood water to drain into the sea and floods will rise higher than before. Furthermore, under the impact of climate change, dangerous hydrometeorological phenomena such as storms, tropical depressions, heavy rain, floods, flash floods will increase... Especially increasing storms with high intensity, heavy rain with high intensity as I said above.

Rising sea levels will make flooding more severe. Pictured is a beach in the central region devastated by waves. Photo: Tien Hung

PV: To minimize human and property damage, what should authorities and people do at this time, sir?

To minimize human and property damage, authorities and people need to regularly monitor and continuously update forecasts and warnings of natural disasters to have appropriate prevention and control measures. Such as having appropriate planning and design of works; having timely and effective prevention and control measures. Options include building retaining walls, finding resettlement areas for people or finding new livelihoods for them, and re-planning rural and urban areas.

At the same time, it is necessary to improve propaganda and raise public awareness about natural disaster prevention and avoidance so that people can proactively prevent and avoid natural disasters. Climate change can affect the characteristics of rain and storms, so previous experiences may no longer be useful in the coming decades. Instead, creative responses are needed so that other countries can take them as lessons, otherwise they will have to suffer consecutive flood disasters in the future.

Chau Nhan area in Hung Nguyen district was heavily flooded during the recent flood. Photo: Quang An

PV: Yes, thank you!

According to the climate change scenario proposed by the Ministry of Natural Resources and Environment, temperatures in all regions of Vietnam tend to increase, with the largest increase in the Northern region. Annual rainfall also tends to increase nationwide. The number of weak and medium storms and tropical depressions tends to decrease slightly or change little, but strong to very strong storms tend to increase. In winter, the number of days with severe cold in the northern mountainous provinces, the Northern Delta, and the North Central region all decrease. The number of hot days tends to increase over most of the country, with the largest increase in the North Central region.

Regarding sea level, the highest sea level rise is in the Hoang Sa and Truong Sa archipelagos with the corresponding values ​​of 58cm (36-80cm) and 57cm (33-83cm); the Mong Cai - Hon Dau and Hon Dau - Deo Ngang areas have the lowest sea level rise of 53cm (32-75cm)... Climate change experts warn that if the sea level rises by one meter, about 39% of the Mekong Delta area, over 10% of the Red River Delta and Quang Ninh, 3% of the area in the coastal provinces of the Central region and over 20% of the area of ​​Ho Chi Minh City will be at risk of flooding.