Soldiers and militia repair a damaged-section of a local road triggered by landslides in Mù Cang Chải Commune, in the northern mountainous province of Lào Cai. —VNA/VNS Photo Tuấn Anh

HÀ NỘI — The northern region is forecast to be hit by a widespread spell of heavy rain, starting from Thursday evening through Saturday, with total rainfall expected to reach 70-150mm across most areas and even exceed 300mm in some locations, heightening the risks of flooding, flash floods and landslides.

The National Centre for Hydro-meteorological Forecasting warned that the northern mountainous and midland regions, rainfall from Thursday evening through Friday is forecast at 50-100mm, with isolated areas receiving more than 200mm.

The Hồng (Red) River Delta is expected to see lower rainfall totals of 30-70mm, although some localities could record more than 150mm.

From Friday night to Saturday, moderate to heavy rain is expected to continue across the region, with widespread accumulations of 20-50mm and isolated areas receiving more than 100mm.

The provinces considered most at risk of torrential rain include Thái Nguyên, Tuyên Quang, Lào Cai, Lai Châu, Điện Biên and Sơn La.

Meteorologists also said that these localities face a high risk of flash floods along small rivers and streams, as well as landslides on steep slopes.

Thunderstorms are also likely to bring hazardous weather, including whirlwinds, lightning and strong gusts.

Forecasters also warned that rainfall exceeding 100mm within three hours could trigger urban flooding in low-lying areas while significantly increasing the risk of flash floods and landslides in mountainous districts.

Residents in affected areas have been urged to closely monitor official weather forecasts and warnings and take precautionary measures to minimise potential damage.

Saturated ground heightens landslide risk

The latest spell of heavy rain comes after persistent downpours between July 15 and 18 left soils on mountain slopes saturated, significantly increasing the likelihood of flash floods and landslides.

Intense rainfall could also cause widespread inundation in low-lying areas, urban centres and industrial zones.

Nguyễn Văn Hưởng, head of the centre’s Weather Forecasting Office, said the most significant factor behind the escalating disaster risk was the prolonged period of rainfall that has affected the northwestern region for several consecutive weeks.

He said a low-pressure circulation centred over the northern region, extending through altitudes of 1,500 to 5,000m, had generated exceptionally heavy rainfall across the region.

The volume of rainfall has exceeded the resilience of infrastructure in the northern mountainous provinces, while floodwaters flowing downstream from upstream catchments have risen sharply.

Combined with days of previous rainfall, mountain soils have become fully saturated, creating conditions conducive to landslides, flash floods and sudden torrents.

Hưởng said monitoring data show that since the beginning of June, the northwestern provinces of Lai Châu, Điện Biên and Sơn La have experienced almost continuous rainfall.

Of the past 48 days, only five have been rain-free, meaning precipitation has been recorded on 43 days.

In Lai Châu Province, showers and thunderstorms have occurred almost daily since July 4, with rainfall generally ranging between 20mm and 40mm each day.

The prolonged wet weather has left the ground continuously waterlogged, with little opportunity to dry out.

Once the soil reaches saturation point, even another spell of moderate or heavy rain can destabilise slopes, greatly increasing the risk of flash floods and landslides.

This explains the series of landslides that have recently occurred across Sơn La, Lào Cai and Lai Châu provinces, he added.

Representatives of Mường Nhé Commune offer condolences to the victim's family in the northern mountainous province of Điện Biên on Wednesday. — VNA/VNS Photo

Lightning strike kills two

Thunderstorms accompanied by lightning struck Mường Nhé Commune in the northern mountainous province of Điện Biên, killing two children and injuring a woman at around 6pm on Wednesday.

The victims were a mother and her two daughters, who were returning home from working in the fields and were about 100m from their house in Xi Ma Village when they were struck by lightning.

The mother, Giàng Thị Bia, 36, sustained injuries, while her daughters, Vừ Thị Nhi, 11, and Vừ Thị Lê, 5, died at the scene.

Following the incident, local authorities visited the bereaved family to offer condolences and assistance with funeral arrangements in accordance with local customs.

The commune authorities also urged residents to closely follow official weather forecasts and warnings and to take timely precautions to reduce the risk of casualties and damage from severe weather. — VNS