Tropical Cyclone (TC) DIANMU originated from the South China Sea, tracked west-northwestwards, and made landfall in Quang Ngai, Viet Nam on the evening of 23 Sep 2021. TC DIANMU weakened into a tropical depression as it moved over Central Viet Nam and Attapeu and Salavan provinces in Southern Lao PDR. TC DIANMU dissipated over eastern Thailand on 24 Sep 2021.
According to the Lao PDR’s National Disaster Management Organisastion (NDMO), TC DIANMU affected several provinces in Lao PDR. NDMO still continue to conduct data collection and response to the affected areas.
• IMPACTS: According to reports from Thailand's Department of Disaster Prevention and Mitigation (DDPM), from the influence of TC DIANMU that moved along the monsoon trough covering the Northeast and Central regions, increased rainfall (heavy to very heavy) was reported in upper regions of Thailand. This resulted in flash floods that affected 71,093 households (355,465 persons) across the following provinces: Chiang Mai, Lamphun, Lampang, Tak, Sukhothai, Phitsanulok, Phetchabun, Phichit, Kamphaeng Phet, Loei, Khon Kaen, Chaiyaphum, Nakhon Ratchasima, Buriram, Surin, Ubon Ratchathani, Prachin Buri, Sa Kaeo, Chanthaburi, Nakhon Sawan, Uthai Thani, Chainat, Lopburi, Suphan Buri, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Nakhon Pathom. Some of the indicated provinces have previously experienced flooding on 16 Sep 2021 due to the effects of the Southwest Monsoon. The situation persists in 23 provinces.
• PREPAREDNESS AND RESPONSE: o Thailand's Geo-Informatics and Space Technology Development Agency (GISTDA) has detected the worst flooding in the northern and central regions. o Prime Minister Prayut Chan-o-cha has visited flood-hit communities of Sukhothai, reportedly the worst-hit area (7,392 households affected mostly in Sri Samrong, Khirimas, and Muang districts). o The Thai Meteorological Department (TMD) forecasts further heavy rainfall for the entire of Thailand and respective relevant authorities have prepared accordingly e.g. installation of barriers and pumps, situation assessment and monitoring, and coordination among the relevant agencies. o The situation is well within the capacity of DDPM to respond.
• IMPACTS: According to reports from the Steering Committees for Disaster Prevention and Control of the localities, as of 25 Sep 2021, TC DIANMU have caused the following: 2,845 families (14,225 persons) affected, 3 people missing, 3 people injured (Binh Dinh-2 missing persons, Ha Tinh-31 families, Nghe An-2,725 families, Phu Tho-1 family, Quang Binh-3 families, Quang Nam-34 families, Quang Ngai-34 families, and Quang Tri-15 families) (VNDMA).
• DAMAGES: 2,725 houses (118 partially damaged), 201 roads, 5 schools, 3,734 ha of agricultural lands damaged (849 ha of rice fields, 2,525 ha of other crops), 5,402 livestock lost (VNDMA).
• PREPAREDNESS AND RESPONSE: o The local disaster management agencies have been encouraged to continue following the direction of Deputy Prime Minister Le Van Tanh to proactively overcome, respond to, record information about, monitor, and communicate the impacts of TC DIANMU. The public was also advised to regularly monitor the situation. o The Ministry of Transport has direct road management units to closely monitor the condition of roads especially those at risk of flooding and landslides and to prepare materials and equipment to remedy impassable roads due to the effects of TC DIANMU. o Relocation of people in deeply flooded areas to safer places and search and rescue for the three missing fishermen are underway by respective authorities.
• The AHA Centre will continue to monitor for further development and issue necessary updates.