Scenario-based seismic risk assessment for Malawi using improved information on earthquake sources and local building characteristics

This study presents scenario-based seismic hazard and risk assessments for Malawi using improved information on earthquake sources and local building characteristics. A case study is focused upon areas near the Bilila-Mtakataka Fault (south of Lake Malawi). The Bilila-Mtakataka Fault is approximately 130-km long, and six segments can be identified along the scarp, which might rupture individually or altogether. The earthquake source models take into account different rupture scenarios in terms of fault geometry and earthquake
magnitude. To represent current building stock in the target region, building surveys are conducted to develop a realistic seismic risk model. Moreover, seismic fragility models for typical masonry buildings in Malawi are developed based on pushover analysis of finite-element models. Finally, all improved model components are integrated to carry out the seismic hazard and risk assessments in Central-Southern Malawi. The new seismic hazard and risk assessments will inform the baseline seismic risk more accurately.