Risk analysis of natural hazards to power grids in Southeast and East Asia

Electricity infrastructure is one of the most essential infrastructure systems for the functioning of our society. It forms the “lifeline” for a prosperous modern economy by supporting the delivery of health, education, and many other services in its day-to-day functioning (Rentschler et al. 2019; Arderne et al. 2020). Weather-related hazards are the leading cause of major power outages, resulting in significant damage (Alemazkoor et al. 2020; Shield et al. 2021).

The power grid is a highly intricate system with varying degrees of (inter)connectivity and redundancy over a wide geographic extent. The complexity of the power grid topology may create system-wide failures, more specifically, the power outages may escalate from local problems to broad interruptions, thereby resulting in widespread, catastrophic impacts that may seriously disrupt socioeconomic activities (Pescaroli and Alexander 2018; Suppasri et al. 2021). Transmission and distribution networks are most vulnerable to storm events and are responsible for most power outages (Nicolas et al. 2019). Another main factor behind the increasing damage from power outages is of socio-economic origin — more and more people and physical assets are located in harm's way due to the rapid development of the economy — climate change is also expected to exacerbate impacts from weather-related outages and then alter the landscape of natural hazard risk to power systems (Forzieri et al. 2018).

Understanding the potential damage caused by natural hazards requires information on their intensity and frequency, as well as how these natural hazards interact with the exposure and vulnerability of assets. In recent years, a great number of studies highlight that ongoing sea-level rise will expose the coastal area to greater risk (Hinkel et al. 2014); while more frequent extreme weather events will enhance the impact of sea-level rise on the coast. However, the risk modelling of natural hazards to power grid assets is mainly studied on a local scale, with little attention has been paid to the exposure of electricity infrastructure at the detailed asset level (Dawson et al. 2018; Arrighi et al. 2021); while many existing studies make generalized assumptions on infrastructure density when modelling the infrastructure risk (Koks et al. 2019).

To fill these gaps, we present the first estimate of exposure and risk of power grids in South-eastern and Eastern Asia to tropical cyclones (wind speed only) and coastal floodings. In this paper, we introduce detailed electricity infrastructure asset maps from collaborative community map – OpenStreetMap (OSM) and broadly-collected government power grid maps, state-of-the-art global hazard maps, and various vulnerability curves of wind and flooding for different types of electricity infrastructure into risk modelling. Strengthening the electricity infrastructure to withstand natural hazards takes priority, it is also important to customers and operators of other infrastructure systems, who rely heavily on electricity. The assessment provides better risk information – the annual repairing costs of electricity infrastructure damaged by natural hazards – which will help to improve power grid design and planning against natural hazards, and further make power grids resilient and sustainable.