Pui Man Kam

and 7 more

The devastating 2022 summer flood in Pakistan displaced about 7 million people in the Sindh province alone. Up to one third of the country’s area, mostly the country’s south, was flooded. Effective response to intensifying and compounding climate change hazards requires impact assessments to include socio-economic components, as well as uncertainties arising from the dynamic interactions between impacts. Such quantitative evidence largely remains limited and fragmented, due to methodological challenges and data limitations. Using the open-source impact assessment platform CLIMADA, we study to what extent flood-related hazards can be used to quantify displacement outcomes in a data-limited region. Using flood depths, exposed population, and impact functions, we link flood vulnerability to displaced people. This allows us to estimate internal displacement resulting from the flood event, and to further assess how displacement varies across different areas. We find that a flood depth threshold of 0.67m (CI 0.35 - 1.10) provides a best fit to all data from Sindh province. We find a negative correlation between displacement and the degree of urbanisation. By testing the performance of our model in explaining differing displacement estimates reported across Pakistan, we show the limitations of existing impact assessment frameworks. We emphasise the importance of estimating potential displacement alongside other impacts to better characterise, communicate, and ultimately respond to the impacts of floods.