Climate service for resilience to overheating risk in Colombo, Sri Lanka: a multi-scale mapping approach (COSMA)


  • University of Reading
  • Glasgow Caledonian University


Sri Lanka, like many other developing countries in South Asia, experiences severe heatwaves that affect the health and livelihoods of hundreds of thousands of residents. The risk to heat exposure will be further exacerbated when the heatwave coincides with the urban heat island in the urban area in a non-linear manner, or when there exists a 'cascading/concurrent' heat hazard indoors (as the majority of the households in Sri Lanka have no access to air conditioning and people spend the majority of their time indoors).

Living in such hot and humid climate for many generations, Sri Lankan people have established the unique and remarkable climatic, historical, cultural and architectural values and knowledge to be resilient to the extreme climate, reflected in the unique vernacular architectural and urban design. However, with rapid urbanisation and economic development, the traditional Sri Lankan vernacular villages and dwellings are being replaced by fast-built, western-style, brick-concrete structures. The indigenous Sri Lankan climate-sensitive design knowledge is being forgotten and is disappearing.

In the developed countries, it has been proved that new data streams, improved forecasts and better visualisation techniques have the potential to improve the utility of predictions for early warning of adverse conditions. However, for the countries in the global south (e.g. Sri Lanka), it is vital to provide such climate services with embedded indigenous design knowledge and use of local resources to improve the resilience to extreme humanitarian disaster.


At the heart of the project are the studies of:

  • how the heatwave overheating risk prediction and assessment could be improved at finer urban and building scales
  • the useful indigenous design knowledge in Sri Lanka for heatwaves mitigtion, and how the designs could be regenerated and re-incorporated into the heatwave action plan and future design practice

COSMA aims to develop an integrated modelling approach by taking into account the urban heat island, building characteristics and vulnerable population to build effective early-warning systems and a city-scale heat action plan. The final outputs of the project will be a series of hierarchical overheating risk and mitigation potential maps across different scales for Colombo, Sri Lanka.


COSMA is a multidisciplinary study that will bring together a group of experts in urban meteorology, building environmental engineering, architecture, urban planning and social science, to work with local stakeholders to deliver SHEAR programme objectives. By working closely with the local community, government and professionals, one important goal of COSMA project is to harvest and regenerate traditional design knowledge (both building and urban scales) from indigenous craftsmen embedded within local culture and traditions, and feed into the heat-exposure risk mitigation plan.

COSMA, led by the University of Reading (UoR), involves collaborations with Glasgow Caledonian University (GCU), and carried out in partnership with a group of well-established Sri Lankan partners: the Department of Meteorology (DoM) and the Institute of Town Planners Sri Lanka(ITPSL) as well as researchers at University of Moratuwa (UoM).