Vietnam: Disruptions due to flooding ongoing across northern regions as of July 31

Heavy rainfall and flooding are affecting parts of northern Vietnam as of July 31. Heavy rainfall and the passage of Tropical Storm Prapiroon have resulted in flooding in recent weeks. Since early July, flooding and landslides have killed dozens of people in northern Vietnam.

Heavy rainfall triggered landslides that resulted in two fatalities in Dien Bien Province July 30. At least 35 houses in the province have collapsed or were flooded, 17 families have been evacuated, and 10 roads have been damaged. Landslides also killed two people in Ha Giang Province, injured two people, and damaged 15 houses in Bac Kan Province, while floodwaters killed one person in Thai Nguyen Province. Parts of the suburbs of Hanoi, including Ben Voi Village, are flooded, affecting around 500 people. A coal mine collapse in Ha Long City in northern Quang Ninh Province killed five people July 29.

The passage of Tropical Storm Prapiroon July 23-25 has also resulted in seven fatalities in Son La Province, two in Dien Bien Province, and one in Hanoi. Nine people are still missing, 1,500 houses were damaged, tens of thousands of hectares of farmland were flooded, and thousands of livestock were lost.

Further adverse weather is likely across the affected area in the coming days. The Vietnam National Centre for Hydro-Meteorological Forecasting (NCHMF) has warned of heavy rainfall of 3-6 cm (1-2.5 inches) across the northern mountainous and midland regions through early Aug. 1 and 3-7 cm (1-3 inches) across northwestern Vietnam and Viet Bac Region through early Aug. 2. Heavy rainfall is forecast to persist over northwestern Vietnam and Viet Bac Region through Aug. 2. The NCHMF has issued a level 1 warning of natural disaster risk due to heavy rain. Landslides, tornadoes, lightning, and strong winds are possible. Officials could update and extend the coverage of weather alerts over the coming days.

Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Disruptions to electricity and telecommunications services are likely where significant flooding, strong winds, or landslides impact utility networks.

Floodwaters and debris flows will probably render additional bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces will likely cause hazardous driving conditions on regional highways. Authorities will probably temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather will likely trigger flight delays and cancellations at regional airports. Authorities will probably suspend port operations or close beach fronts along the South China Sea if strong winds trigger hazardous sea conditions. Flooding will likely block regional rail lines; freight and passenger train delays and cancellations are probable in areas with heavy rainfall and potential track inundation.

Localized business disruptions are likely in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities and some employees' inability to reach work sites.