The DamageCost Model: A Co-created Open-Source Tool for Assessing the Socioeconomic Impacts of flooding

The DamageCost model provides a methodological and modelling framework to support comprehensive and multi-sectoral economic damage assessments of flooding from pluvial, coastal, and riverine sources. Developed as an open-source QGIS plugin, the model rests on open geographical data and includes depth-damage functions for multiple economic sectors and supplemented by more detailed socioeconomic data on people in flooding risk areas. The skills of the model and methodological issues related to socioeconomic assessment of flooding are illustrated in relation to a case study for a Danish city (Esbjerg) and an assessment of flooding risks for Denmark. The DamageCost model is from a socioeconomic perspective assessing risks of flooding events as a basis for decision making on adaptation strategies. To examine the sensitivity of adaptation solutions towards uncertainties in climate projections and assumptions applied to the economic assessment, several climate change scenarios can be combined with variations in the applied damage functions. Applications of the model in the national context of Denmark projected total flood damages from storm surges of up to 32 billion EUR over the next century. Additionally, the local case study identified a seawall height with a net benefit of 36 million EUR and revealed that floods disproportionately affect lower-income households. Its co-created nature and management by a municipal partnership facilitate the mainstreaming of risk assessment into local planning, and policy relevance has in this way been supported. Future developments include updated damage functions, adding new sectors and creating a generic cost database to support international applications.