/ / Monthly Disaster Outlook



For the month of August 2021, a total of 72 disasters were reported. The ASEAN Member States that were affected were Indonesia, Malaysia, Myanmar, the Philippines, Thailand and Viet Nam. Most of the disasters (72.22%) occurred in Indonesia and comprised nearly half, 45.08%, of the total number of affected people for the month. The share of the disaster-affected people for other ASEAN Member States was as follows: (1) Malaysia-0.07%, (2) Myanmar-0.03%, (3) Philippines-0.13%, (5) Thailand-53.57% and (6) Viet Nam-1.15%. August 2021 saw disasters affecting 92 per 100,000 people* and displacing 1 per 100,000 people* in the region, three times and 57 times fewer than the previous month, respectively. August 2021 accounted for 9.59% of the total disasters reported so far in the current year.

Most of the disasters that occurred in August 2021 were floods (70.83%) and this is consistent with August of the previous year and August on a five-year average (2016-2020). August 2021 saw hydrometeorological disasters (droughts, floods, rain-induced landslides, storms and winds) dominating the disasters that affected the region for the month (98.6%). The reported disasters in the region for August 2021 in comparison with the historical data (average for August 2016-2020) indicates that there were 2.88x more reported disasters; 3.25x fewer people affected; 29.18x fewer people displaced; 3.24x more houses affected to some extent; 2.89x fewer lives lost; 25.17x fewer people suffering injuries; and lastly, 18.5x fewer people reported missing.

Geophysically, 29 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). Recent volcanic activity was reported for Ili Lewotolok and Merapi (Alert Level III), Semeru, Dukono, and Ibu (Alert Level II) in Indonesia by the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), and Taal (Alert Level 2), Bulusan and Kanlaon (Alert Level 1) by PHIVOLCS. None have resulted in disasters but are continuously being monitored.

*Computed based on 2020 population data from worldometers.com



According to the ASEAN Specialised Meteorological Centre (ASMC), compared with the average value from 2001-2020, during August 2021, rainfall was above-average over much of the ASEAN region and below-average over the northeastern ASEAN region. The largest positive anomalies (wetter conditions) were detected over the equatorial region for both satellite-derived rainfall estimate datasets (GSMaP-NRT and CMORPH-Blended). Coincidingly, numerous hydrometeorological disaster events were reported for this area. A disaster (caused by thunderstorms, flooding and landslide), though minor, was reported in northern Viet Nam despite the largest negative anomalies (drier conditions) for the region for August 2021 being detected over the area.

Drought was reported in Cilacap Regency, Central Java, in Indonesia. Based on Figure 2, the equatorial region, along with central and northern Myanmar, experienced near- to below-average temperatures with the warmest anomalies being detected over northern Viet Nam.



According to the situational report from the Philippines’ National Disaster Risk Reduction Management Council, since 28 July 2021 the Southwest Monsoon has brought intense rains to multiple regions of the Philippines and has since affected 312,605 families (1,222,241 persons) from 1,117 barangays. Related incidents to the Southwest Monsoon that impacted multiple regions in the Philippines were floods, rain-induced landslides, a mudslide, an overflowing spillway and swollen rivers. 129 roads and three bridges were affected and 12 roads and one bridge remain impassable. 1,723 houses have reportedly been damaged. The estimated cost of damage to agriculture is reported to be around USD 4,686,168.51 incurred in Regions I, III, VIII, IX and CAR. With regard to infrastructure, an estimated USD 721,025.94 worth of damage has been reported. A total of 40 cities/municipalities were declared under a State of Calamity. Assistance (in the forms of financial, family food packs, other food items, family kits, hygiene kits, sleeping kits, kitchen kits, medical assistance, non-food items) worth USD 204,497.13 have been provided to victims in Regions I, III, VI, CAR and MIMAROPA. 



In the coming month, for parts of the ASEAN region north of the Equator, Southwest Monsoon conditions are forecast to continue to persist. The northern ASEAN region will continue to experience its traditional wet season and the southern ASEAN region, its traditional dry season. For October, the equatorial ASEAN region is expected to have increased rainfall during the latter part of the month as the Southwest Monsoon conditions transition into the inter-monsoon period. Southwest Monsoon-associated prevailing winds are expected to blow from the southeast or southwest and gradually weaken and become light and variable in direction during the transition into the inter-monsoon period.

An increased chance of above-normal rainfall over much of the ASEAN region is foreseen for the September to November 2021 period with the highest likelihood over central and southern parts of the Maritime Continent. La Niña-like conditions were detected in August but for the rest of the year, the forecast is still split between ENSO-neutral and La Niña conditions developing. The Indian Ocean Dipole (IOD) is currently in the negative phase and is forecast to return to neutral by November or December 2021. During a negative IOD phase, waters in the eastern Indian Ocean (near Indonesia) tend to be warmer than normal and the southern ASEAN region tend to experience above-average rainfall. Most parts of the ASEAN region will experience warmer-than-usual temperatures from September to November 2021.

Considering the IOD being in the negative phase, the outlook for the equatorial ASEAN region, the outlook for over much of the ASEAN region, and the disaster data records from the ASEAN Disaster Information Network, the number of disaster events (particularly hydrometeorological disasters) and the number of affected persons, are expected to increase in frequency and number, respectively, as the year ends. National Disaster Management Organisations (NDMOs), relevant authorities and agencies and the public are advised to take necessary preparations and actions accordingly.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.


Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig


The AHA Centre’s estimation is based on data and information shared by National Disaster Management Organisations (NDMOs) and other relevant agencies from ASEAN Member States, international organisations, and news agencies. Further information on each recorded significant disaster, description, and detail of data and information are available at: http://adinet.ahacentre.org/reports.