Economic Outlook for Southeast Asia, China and India 2024

Brunei Darussalam

Introduction

Brunei Darussalam is generally perceived as facing little disaster risk despite its location in Southeast Asia, a highly disaster-prone region. Nevertheless, it faces risks from several types of disasters and has a relatively large population of vulnerable people. Floods, and landslides are the most common disasters, particularly as a result of short periods of heavy rainfall. While landslides are not especially damaging, they can disrupt transportation networks, resulting in negative economic consequences.

The hazardscape

Brunei Darussalam faces a risk of floods, landslides, droughts, storms, earthquakes and wildfires. It is additionally exposed to the potential impacts of tsunamis generated in the region (Ndah and Odihi, 2017[1]). Floods and landslides, especially associated with the rainy season, constitute the most frequent and impactful disasters, and inflict considerable social and economic damage (Jamalullail et al., 2021[2]; Ndah, Dagar and Becek, 2016[3]). Severe disaster events, such as floods or wet landslide events, affected thousands of people and damaged hundreds of buildings in the country in 2009, 2011 and 2014 (Ndah, Dagar and Becek, 2016[3]).

Heavy rainfall events, which occur mainly during the rainy season between October and May, have the potential to trigger coastal, riverine (fluvial) floods, flash (pluvial) floods and landslides (Yassin et al., 2021[4]). Heavy rainfall lasting only one or two hours can lead to flooding of up to one metre deep in some inland areas (JICA, 2012[5]). Severe events occur typically during the wettest months of December and January and can affect the whole country given its small size (Ndah, Dagar and Becek, 2016[3]). Flooding occurs mainly in low-lying regions, especially in the Tutong and Belait districts, with the Tutong district estimated to have the highest integrated flood vulnerability (Ndah, Dagar and Becek, 2016[3]; Jha et al., 2020[6]). Most residential areas are located on coastal plains and near rivers (Yassin et al., 2021[4]). Kampong Ayer, a traditional settlement built on stilts above the Brunei River just outside the capital city, has a population of more than 10 000 people and is at a high risk of flooding. The risk is highest when heavy precipitation combines with a high tide that sea-level rise can exacerbate (JICA, 2012[5]).

The risk of severe landslide damage is relatively low. However, landslides in the hilly regions affect transportation networks. On top of weather and geological factors, the dynamics of rapid urbanisation and loss of vegetation cover contribute to an increase in landslide risk (Jamalullail et al., 2021[2]). As of 2017, no landslide mitigation strategies had been implemented despite the potential for landslide damage. The reactive measures employed were not perceived to be effective or sustainable by experts, despite government spending of approximately USD 3.6 million annually on slope rectification projects (Ndah and Odihi, 2017[1]).

Brunei Darussalam has recently experienced an increase in forest fires, most likely as a consequence of elevated temperatures, more variable rainy seasons and longer dry spells associated with the intensification of the El Niño Southern Oscillation (ENSO) cycle. These forest fires adversely affect human health due to reduced air quality, and negatively impact the forestry sector. The Brunei-Muara district is estimated to be most affected by fires (Shahriar et al., 2019[7]). In the last few decades, the country has also been experiencing increasing haze and air pollution as a result of forest fires across in neighbouring Indonesia (Shahriar et al., 2019[7]).

The earthquake risk in Brunei Darussalam is considered to be low and the country has not suffered any catastrophic earthquake losses, but damaging earthquakes do occur causing estimated annual losses of nearly USD 6 million (Ndah and Odihi, 2017[1]). While there are no recent records of tsunamis, the coastline is exposed to tsunami risk.

Winds strong enough to cause damage also occur regularly at the tail end of tropical storms during the southwest monsoon or during heavy thunderstorms. The country experienced prolonged droughts in the 1960s and 1990s, but drought risk is currently perceived to be low. The construction of several dams in the last two decades has increased the country’s water storage capacity and drought resilience (CFE, 2022[8]).

Climate-change perspective

Climate change is increasing the threat of floods, landslides, heatwaves and forest fires in Brunei Darussalam as it shifts rainfall patterns, increases temperatures and causes sea-level rise (CFE, 2022[8]; Hasan, Ratnayake and Shams, 2016[9]). Future sea-level rise is expected to increase the risk of coastal floods, and reduce river drainage, with the most populated inland floodplains becoming vulnerable to tidal floods by the end of the century (Ratnayake et al., 2022[10]).

Challenges for disaster risk management policy

Flood risk could be reduced by investment in small-scale individual flood mitigation measures, such as elevation of residential properties or flood-proofing, and by implementation of ecosystem-based measures such as restoration of mangroves or riverside vegetation (Islam, Reinstädtler and Ibrahim, 2023[11]). Flood management may benefit from an enhanced capacity for heavy rainfall forecasting, which would require a better and more comprehensive understanding of intra-seasonal rainfall variability and anomalous rainfall events (Ndah, Dagar and Becek, 2016[3]). Flood monitoring, forecasting and warning systems should be improved, especially as regards communicating risk information to the general public (Islam, Reinstädtler and Ibrahim, 2023[11]). More detailed landslide mapping and regular monitoring should be conducted and incorporated into urban planning to mitigate landslide risk (Jamalullail et al., 2021[2]). As regards forest fires, potential improvements in forest fire mitigation include more effective personnel planning, increasing fire departments’ capacity and training, and planning to avoid the use of treated water in fighting fires (Shahriar et al., 2019[7]).

Early hazard warnings are broadcast via television, radio or SMS, but there are gaps in delivering the hazard information, especially to coastal fishing communities and ships offshore (CFE, 2022[8]). Brunei Darussalam’s warning system is operated manually and requires personnel for constant monitoring, making the system less efficient and unnecessarily slow. The country’s disaster warning system could be improved by establishing processes designed around a modern digital alert system (Yassin et al., 2021[4]).

Disaster data appear relatively less extensive in Brunei Darussalam than in other countries in the region. This could indicate a need to improve data collection, particularly with regard to smaller-scale recurrent events (Ndah, Dagar and Becek, 2016[3]).

References

[7] Awaludin, A. et al. (eds.) (2019), “Risk assessment for forest fire in Brunei Darussalam”, MATEC Web of Conferences, Vol. 258, p. 05033, https://doi.org/10.1051/matecconf/201925805033.

[8] CFE (2022), Disaster Management Reference Handbook: Brunei, https://reliefweb.int/attachments/63f601d6-c8b0-40c5-90c1-0ec8c01cf124/CFE-DM-BruneiDMRH-2022.pdf.

[9] Hasan, D., U. Ratnayake and S. Shams (2016), “Evaluation of rainfall and temperature trends in Brunei Darussalam”, AIP Conference Proceedings, https://doi.org/10.1063/1.4940282.

[11] Islam, S., S. Reinstädtler and K. Ibrahim (2023), “Floods in Tutong District, Brunei Darussalam and the Role of Tutong River: Approaches for Mitigation Measures”, in Disaster Risk Reduction for Resilience, Springer International Publishing, Cham, https://doi.org/10.1007/978-3-031-43177-7_8.

[2] Jamalullail, S. et al. (2021), “Preliminary analysis of landslide hazard in Brunei Darussalam, SE Asia”, Environmental Earth Sciences, Vol. 80/16, https://doi.org/10.1007/s12665-021-09815-z.

[6] Jha, D. et al. (2020), “Indicator Based Assessment of Integrated Flood Vulnerability Index for Brunei Darussalam”, International Journal of Disaster Risk Management, Vol. 2/2, pp. 47-70, https://doi.org/10.18485/ijdrm.2020.2.2.4.

[5] JICA (2012), Data Collection Survey on ASEAN Regional Collaboration in Disaster Management: Final Report. Country Report Brunei, https://openjicareport.jica.go.jp/pdf/12085536.pdf.

[3] Ndah, A., L. Dagar and K. Becek (2016), “Dynamics of Hydro-Meteorological Disasters: Revisiting the Mechanisms and Drivers of Recurrent Floods and Landslides in Brunei Darussalam”, International Journal of Earth and Atmospheric Science, Vol. 3/1, pp. 01-16, https://www.researchgate.net/publication/305316042_Dynamics_of_Hydro-Meteorological_Disasters_Revisiting_the_Mechanisms_and_Drivers_of_Recurrent_Floods_and_Landslides_in_Brunei_Darussalam.

[1] Ndah, A. and J. Odihi (2017), “A Systematic Study of Disaster Risk in Brunei Darussalam and Options for Vulnerability-Based Disaster Risk Reduction”, International Journal of Disaster Risk Science, Vol. 8/2, pp. 208-223, https://doi.org/10.1007/s13753-017-0125-x.

[10] Ratnayake, U. et al. (2022), “Impact of Sea-Level Rise on a Coastal Catchment of Brunei Darussalam”, in Advances in Sustainability Science and Technology, Sustainable Water Resources Management, Springer Nature Singapore, Singapore, https://doi.org/10.1007/978-981-16-7535-5_4.

[4] Yassin, M. et al. (2021), “LoRa Based Real-time Flood Detection and Monitoring System: A Brunei Darussalam Based Study”, 2021 International Conference on Electronics, Communications and Information Technology (ICECIT), https://doi.org/10.1109/icecit54077.2021.9641097.