Vol 72 – MONTHLY DISASTER REVIEW AND OUTLOOK

GENERAL REVIEW OF APRIL 2021

For the month of April 2021, a total of 80 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, the Philippines, Thailand and Viet Nam with the majority of the disasters (72.5%) occurring in Indonesia. April 2021 saw disasters affecting 174 per 100,000 people and displacing 16 per 100,000 people in the region. April 2021 also accounted for approximately one-fifth (19.6%) of the total disasters and over a quarter (27.66%) of the total economic losses reported so far in the current year.

A majority of the disasters that occurred in April 2021 were floods (60%) and this is consistent with April of the previous year and April on a five-year average (2016-2020). The reported disasters in the region for April 2021 in comparison with the historical data (average for April 2016-2020) indicates that there were 4x more reported disasters; almost 13x more people affected; almost 10x more people displaced; 20x more houses affected to some extent; 20x more lives lost; 16x more people suffering injuries; and lastly, 5x more people reported missing.

Geophysically, 30 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Meteorological, Climatological, and Geophysical Agency (BMKG) and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). A Magnitude 6.7 earthquake (later downgraded to M6.1) that occurred off the southern coast of Java in week 14 claimed eight lives, caused injuries to 24 individuals, displaced 782 people and caused damage to thousands of houses, hundreds of schools, a number of hospitals and almost 100 places of worship. Volcanoes in Indonesia and the Philippines have shown recent volcanic activity but have not resulted in significant events and are being continuously monitored.

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during April 2021, rainfall in mainland Southeast Asia and the Malay Peninsula (where a fifth of the recorded disasters occurred) was above the 2001-2020 average for the month. The largest number of positive anomalies, or wetter conditions, were recorded in Thailand (where five disasters were recorded) and Lao PDR. Other large positive anomalies that were observed were in the eastern part of Central Philippines and in Nusa Tenggara due to Typhoon SURIGAE and Tropical Cyclone SEROJA, respectively. Much of the rest of the Maritime Continent, however, experienced below-average rainfall. This is in light of the majority of the disasters recorded in April 2021 being weather-related. 

SPOTLIGHT

An unusual meteorological phenomenon—the Fujiwhara effect (two tropical cyclones forming in close proximity to one another making their trajectory and tracks difficult to predict) was observed this month. One of the two tropical cyclones—Tropical Cyclone SEROJA ripped through the Nusa Tenggara islands of Indonesia and Timor Leste. Tropical Cyclone SEROJA resulted in flooding, landslides and strong winds in 21 regencies/cities in East Nusa Tenggara and three regencies in West Nusa Tenggara, Indonesia. It resulted in 184 deaths (182 in East Nusa Tenggara and two in West Nusa Tenggara), injuries to 155 persons, 47 missing, more than 80,000 displaced, and almost 500,000 people affected. A total of 55,000 houses and 3,600 public facilities were damaged due to the effects of Tropical Cyclone SEROJA in the Nusa Tenggara islands

SEASONAL OUTLOOK

Inter-monsoon conditions typically transition into the Southwest Monsoon in June with the prevailing winds strengthening and blowing from the southeast or southwest. The Southwest Monsoon season is the traditional dry season for the southern ASEAN region, which brings persistent dry conditions over the region. For the northern ASEAN region, the Southwest Monsoon is the traditional wet season.

For the May to July 2021 period, models predict below-normal rainfall over parts of the western and central Maritime Continent, in particular over parts of Sumatra, Peninsular Malaysia and Borneo. Elsewhere, there is no consistent prediction for the rainfall outlook between the models consulted. La Niña conditions were present over the tropical Pacific Ocean at the end of April, with climate models predicting its continued weakening to neutral conditions during May – June.

Warmer-than-usual temperatures are expected for much of the Maritime Continent, with near to warmer-than-usual temperature elsewhere.

The increase in shower activities is expected to help subdue the hotspot and haze situation over the Mekong sub-region. In the southern ASEAN region, isolated hotspots with localised smoke plumes may develop in areas with below-normal rainfall over Sumatra, Peninsular Malaysia and Borneo. As the traditional dry season typically sets in during June/July, the hotspot and haze situation is expected to elevate with an increased risk of transboundary smoke haze in the region.

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 Member States’ National Meteorological and Hydrological Services should be consulted.

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

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