GENERAL REVIEW OF OCTOBER 2021
For the month of October 2021, a total of 144 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Malaysia, the Philippines, Thailand and Viet Nam. Most of the disasters (54.86%) occurred in Indonesia but the highest number of affected people was reported in the Philippines which comprised more than half of the tally for the month of October (55%). The share of the disaster-affected people for other ASEAN Member States was as follows: (1) Cambodia-0.66%, (2) Indonesia-25.40%, (3) Malaysia-0.08%, (4) Thailand-15.89%, and (5) Viet Nam-2.97%. October 2021 saw disasters affecting 335 per 100,000 people* and displacing 11 per 100,000 people* in the region, recording a 22.63% decrease and a 35.29% respectively, from the previous month. October 2021 accounts for 13.64% of the total disasters (1,056) reported so far in the current year.
Most of the disasters that occurred in October 2021 were floods (62.5%) and this is consistently the most recorded type of disaster for October of the previous year and October on a five-year average (2016-2020). October 2021 saw hydrometeorological disasters (droughts, floods, rain-induced landslides, storms, winds) affecting 99.6% of the total affected persons for the month. The reported disasters in the region for October 2021 in comparison with the historical data (average for October 2016-2020) indicates that there were 8x more reported disasters; 1.34x fewer people affected; 1.22x fewer people displaced; 1.97x more houses affected to some extent; 6.58x fewer lives lost; 22.47x fewer people suffering injuries; and lastly, 14.05x fewer people reported missing.
Geophysically, 18 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Myanmar’s Department of Meteorology and Hydrology (DMH), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). In Bali Indonesia, a magnitude 4.8 earthquake, albeit not a significant earthquake, affected 7,690 people and damaged 2,320 houses. Recent volcanic activity was reported for Ili Lewotolok (Alert Level III) and Semeru, Kerinci, Ibu, Karangetang, Krakatau (Alert Level II) in Indonesia, and Taal (Alert Level 2) and Kanlaon (Alert Level 1) in the Philippines.
*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 October 2021, rainfall was above-average over much of the northern ASEAN region and a mix of below- to above-average for the southern ASEAN region (Figure 1). The largest positive anomalies (wetter conditions) were detected over the eastern Mainland Southeast Asia for both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended). This is associated with the developments of Severe Tropical Storm KOMPASU. A second tropical storm, Tropical Storm LIONROCK, affected central Philippines at the beginning of October, which is the major reason for the positive anomalies in central Philippines and the ocean region around the Philippines. Negative anomalies (drier conditions) were recorded over western and northern parts of Borneo. For the rest of the ASEAN region, rainfall tended to be near-to above-average during October 2021.
In the second half of October 2021, according to the ASMC, the Southwest Monsoon had transitioned into the inter-monsoon period. Climatologically, the inter-monsoon conditions are likely to prevail over the ASEAN region in the coming month of November as the conditions transition into the Northeast Monsoon by December. During this inter-monsoon period, prevailing winds are forecast to be generally light and variable in direction. Increased rainfall is expected, particularly over the areas of the ASEAN region near the equator, due to the equatorial proximity of the monsoon rain band.
In the coming three months (November 2021 to January 2022), the Maritime Continent and southeastern Mainland Southeast Asia are looking at an increased chance of above-normal rainfall. The areas with the highest chances are southern and eastern parts of the Maritime Continent. La Niña conditions have been detected and are now present according to the ASMC. This entails wetter-than-average rainfall conditions and cooler conditions in the region. Additionally, most models are predicting these conditions to last or be experienced until early 2022. As the month of October ended, a negative Indian Ocean Dipole (IOD) that brought greater precipitation east of the Indian Ocean was present and this negative IOD was expected to return to neutral in the month of November 2021 (positive IOD causes droughts in Southeast Asia). Temperatures that are warmer than usual are likely for much of the Maritime Continent and Myanmar in the coming three months (November 2021-January 2022).
The dry season over the southern ASEAN region ended in October 2021. Meanwhile, for the northern ASEAN region, the traditional dry season typically sets in by year-end.
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.
*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.