Towards resilience to pluvial flood events

Institute

  • Newcastle University

Background

Many growing cities in low and middle-income countries experience flash floods on an annual basis, exacerbated by inadequate drainage systems and increased permeable surfaces from rapid and unplanned urbanisation, resulting in in little opportunity for individuals and infrastructure to recover. Pluvial flooding is a hazard for a wide range of often already fragile, interdependent infrastructure sectors: water and waste water, transport, energy generation and distribution, solid waste and ICT, as well as housing and livelihoods.

Flood-related losses and damage to people's property is escalating, as is the cost of maintaining roads and drainage channels. The hazard also increases the incidents of water-borne diseases such as cholera, typhoid, dysentery and malaria.

Flood events typically occur in low-lying areas often occupied by informal settlements, however, the wider, knock-on effects on transportation, economy and infrastructure also influence middle and upper income groups, with whole cities becoming exposed.

Early-warning systems for weather events are limited to predicting rapid, high-magnitude events (such as hurricanes) or slow-onset events (such as droughts) with little attention paid to rapid, low magnitude events such as flash flooding from intense rainfall that typically lasts between two and six hours and can therefore only have limited impact on reducing the risk from pluvial flooding.

Aims

The aim of this catalyst project is to understand the hydro-meteorological factors that lead to pluvial flash flooding and the impact this hazard has on local communities and their supporting infrastructure. Furthermore, this project will test the transferability of three impact models that will better prepare communities and emergency services to respond in a pluvial flood event and inform decision makers on how to improve infrastructure resilience.

The research will benefit a wide range of stakeholders including:

  • individuals and communities, by providing appropriate information for them to be better prepared during pluvial flood events and to change behaviours and take measures to adapt to the risk
  • emergency services and responders, who could make use of the disruption risk mapping to support response and recovery during pluvial flood events
  • local authority and infrastructure providers, who will have improved evidence of where to target adaptation to limit direct and indirect impacts on housing, infrastructure, the economy and livelihoods

This catalyst research will demonstrate how the approaches used could be combined with real-time weather predictions to support the development of a real-time, decision-support system during pluvial flood events.

Approach

Demonstrated in Kampala, Uganda, this catalyst will address the five objectives:

  • Explore past impacts of, and current vulnerability to, extreme rainfall, capitalising upon existing data and tools, and local knowledge.
  • Characterise extreme rainfall associated with pluvial flooding in the city of Kampala.
  • Enhance understanding of the location and magnitude of impacts of pluvial flooding on people and infrastructure to assess pluvial risk as a function of hazard and impacts.
  • Assess effective responses and preparation to enhance resilience to pluvial extremes.
  • Co-create appropriate communication mechanisms to enhance the uptake of risk and resilience information in practice by communities, NGOs and local government agencies.