Vietnam: Disruptions due to flooding ongoing across central regions as of Oct. 17 /update 1

Event

Disruptions due to flooding are ongoing across parts of central Vietnam as of Oct. 17. Heavy rainfall associated with the passing of Tropical Storm Sonca, which made landfall over Quang Ngai Province early Oct. 15, has triggered widespread flooding in Quang Binh, Quang Tri, Quang Nam, and Thua Thien Hue provinces, as well as parts of Da Nang City. Authorities have reported six flood-related fatalities in Da Nang and two fatalities in both Quang Nam and Thua Thien Hue provinces. More than 37,000 people living in areas at risk of flooding and landslides in Thue Thien Hue Province have been relocated to evacuation centers. Due to rising river levels, authorities are reportedly planning to evacuate around 14,000 people in Quang Tri Province. Around 620 people in Da Nang and 240 in Quang Tri province have also been evaluated due to the floods. Around 20,000 homes have been damaged in Thua Thien Hue and hundreds of others across the rest of the affected area. The floods have also severely damaged transport networks in the affected area. The Hai Van Pass that connects Da Nang and Thua Thien Hue was reopened to traffic Oct. 16 and the Hai Van Tunnel was closed Oct. 14-15. Electricity supply infrastructure has also been damaged by the floods, causing power outages for around 200,000 customers.

Further adverse weather is likely across the affected area in the coming days as Typhoon Nesat approaches Vietnam from the South China Sea. The storm system is expected to weaken into a tropical storm or depression before making landfall north of the path of Tropical Storm Sonca Oct. 21-22.

Hazardous Conditions
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 the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible where significant flooding, strong winds, or landslides impact utility networks.

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

Severe weather could also trigger flight delays and cancellations at airports in the region, including but not limited to Da Nang International Airport (DAD). Authorities may temporarily suspend port operations or close beach fronts along the South China Sea if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Localized business disruptions may occur 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.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Vietnam National Centre for Hydro-Meteorological Forecasting