Vol 73 – MONTHLY DISASTER REVIEW AND OUTLOOK

GENERAL REVIEW OF MAY 2021

For the month of May 2021, a total of 105 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Malaysia, Myanmar, the Philippines, and Thailand. A majority of the disasters (64.76%) occurred in Indonesia, which also saw 69.5% of the total number of affected people for the month (Cambodia – 2.1%, Malaysia – 0.7%, Myanmar – <0.1%, Philippines – 26.1%, Thailand – 1.5%). May 2021 saw disasters affecting 60 per 100,000 people* and displacing 4 per 100,000 people* in the region. May 2021 also accounted for roughly one-fifth (20.5%) of the total disasters reported so far in the current year.

The majority of the disasters that occurred in May 2021 were floods (58%) and this is consistent with May of the previous year and May on a five-year average (2016-2020). Flood victims comprised a little over three-quarters (77%) of the total number of affected people. The reported disasters in the region for May 2021 in comparison with the historical data (average for May 2016-2020) indicates that there were 5.5 time more reported disasters; almost 5 times more people affected; almost 3 times more people displaced; twice as many houses affected to some extent; 32 times fewer lives lost; 5 times fewer people suffering injuries; and lastly, 100 times fewer people missing.

Geophysically, 28 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). A Magnitude 6.2 earthquake (later downgraded to M5.9) that occurred 57 km southeast of Blitar in East Java in week 20 caused injuries to two individuals, affected 6,200 persons, and caused damage to thousands of houses, and hundreds of public facilities. Volcanoes in Indonesia and the Philippines have shown recent activity but they have not resulted in significant events and are continuously being monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during May 2021, the largest positive anomalies (wetter conditions) were detected in southern Philippines due to Tropical Depression 03W (local name: Crising). Despite below-average rainfall over the southern Maritime Continent, over half of all recorded disasters that were apparently hydrological in nature (flooding and severe local storms) were reported across Indonesia. A mixture of below and above-average rainfall was observed in Mainland Southeast Asia.

SPOTLIGHT

Over the tropical Pacific Ocean, La Niña conditions declined and returned to El Niño Southern Oscillation (ENSO)-neutral conditions by the beginning of June. The sea surface temperatures in the central and eastern Pacific Ocean continued to warm, with atmospheric indicators (cloudiness and wind anomalies) remaining consistent with the ENSO-neutral conditions. ENSO-neutral conditions are neither El Niño (warming of ocean surface, reduced rainfall in Indonesia) nor La Niña (cooling of ocean surface, increased rainfall in Indonesia), which are the extreme phases of the ENSO cycle.

SEASONAL OUTLOOK

According to the ASEAN Specialised Meteorological Centre (ASMC), through May 2021, the monsoon rain band continued to move northwards over the northern ASEAN region. Concurrently, the prevailing winds over most of the southern ASEAN region strengthened to blow mainly from the southeast or southwest, in line with the transition to Southwest Monsoon conditions. With a strengthening of the prevailing winds, Southwest Monsoon conditions are expected to become fully established in June 2021. The Southwest Monsoon season is likely to extend through the June–August period and is the traditional dry season for the southern ASEAN region, characterised by persistent dry conditions over the region. For the northern ASEAN region, the Southwest Monsoon season is the traditional rainy season.

For the June to August 2021 period, models predict a small increase in chance of above-normal rainfall over parts of the southwestern Maritime Continent. Elsewhere, there is no consistent prediction for the rainfall outlook between the models consulted for much of the region. The La Niña event is nearing its end and most ENSO indicators are generally consistent with ENSO-neutral conditions. For July and August, ENSO-neutral conditions are forecast.

Warmer-than-usual temperatures are expected for much of the ASEAN region, with higher confidence over the Maritime Continent.

As the southern ASEAN region enters the traditional dry season, increased hotspot activities and the development of smoke plumes are likely in fire-prone parts of the region. In the coming months, it is expected that the hotspot and smoke haze situation may deteriorate in parts of the southern ASEAN region that experience prolonged dry conditions.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC), ASEAN Disaster Monitoring and Response System (DMRS), Cambodia National Committee on Disaster Management (NCDM), Badan Nasional Penanggulangan Bencana (BNPB), Malaysia Agensi Pengurusan Bencana Negara (NADMA), Myanmar Department of Disaster Management (DDM), National Disaster Risk Reduction and Management Council (NDRRMC), Thailand Department of Disaster Prevention and Mitigation (DDPM), Viet Nam Disaster Management Authority (VNDMA), Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), Philippine Institute for Volcanology and Seismology (PHIVOLCS)

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