Periodic Reporting for period 1 - MulHaRes (A probabilistic decision framework for MULti-HAzard RESilience of residential building portfolios subjected to floods and landslides)
Reporting period: 2020-06-01 to 2022-05-31
Floodings and landslide events (such as mudflows) are the most frequent natural disasters provoked by heavy rainfalls. Their occurrences often cause significant physical damage to the built environment, leading to severe economic losses and social disruptions in communities. To promote disaster resilience of communities, sophisticated models are needed to support citizens in making risk-based decisions on disaster mitigation actions. Considering the impacts of floodings and mudflows on the European residential community, the EU-funded MulHaRes project aimed to develop a decision-making approach that first establishes models to estimate physical hazard impacts on residential buildings; and then performs benefit analyses on hazard-retrofit options to find the optimal solutions for minimizing these associated impacts.
In conclusion, the developed approach gives reliable resulting models that make "holistic" impact estimates on typical EU residential buildings under flood and mudflow actions, considering potential damage on "any building item and content item" and their associated "uncertainties." Moreover, the developed models distinguish differences in impact estimates and decision actions between "individual buildings" and "building portfolios". Therefore, the project outcomes can be widely used by research agencies, practitioners, and academicians seeking to address public policy issues related to the impacts of natural hazards and public investments in hazard-risk mitigation. Moreover, the project outcomes are of commercial value. They can be adapted to use by any EU country to develop insurance models, especially in the lack of any collected field data. Lastly, this fellowship helped the researcher Dr. Derya Deniz fully integrate into the host institution Ozyegin University, and supported her in making a significant career advancement and establishing an internationally well-recognized academic career in this research area.
In conclusion, the developed approach gives reliable resulting models that make "holistic" impact estimates on typical EU residential buildings under flood and mudflow actions, considering potential damage on "any building item and content item" and their associated "uncertainties." Moreover, the developed models distinguish differences in impact estimates and decision actions between "individual buildings" and "building portfolios". Therefore, the project outcomes can be widely used by research agencies, practitioners, and academicians seeking to address public policy issues related to the impacts of natural hazards and public investments in hazard-risk mitigation. Moreover, the project outcomes are of commercial value. They can be adapted to use by any EU country to develop insurance models, especially in the lack of any collected field data. Lastly, this fellowship helped the researcher Dr. Derya Deniz fully integrate into the host institution Ozyegin University, and supported her in making a significant career advancement and establishing an internationally well-recognized academic career in this research area.
The MulHaRes project develops a probabilistic decision framework to support the "multi-hazard resilience" of EU residential building stocks under rainfall-triggered floods and mudflows. First, a typical EU residential building set was created and disassembled into components. The damage potential of each structural, nonstructural, and content component of the buildings was examined for various hazard depths and velocities of flooding and mudflow actions. Repair cost and time for each damaged component were obtained considering the individual failure limit of the components. Then, all components and associated variabilities were probabilistically assembled to estimate the total losses and repair times on residential buildings. The developed impact models (damage, repair cost, repair time) distinguish between different residential buildings based on occupancy type, lateral resistance design, foundation type, construction finish quality, and the number of stories. Next, the developed impact models for individual buildings were extended into models for building portfolios, considering a virtual EU community under multi-hazard scenarios of flooding and mudflow. The effects of uncertainties associated with building and hazard properties were considered, and spatial correlations in hazard demand and common building configurations and practices were reflected in an aggregated impact and resilience assessment of building portfolios. Lastly, several retrofit actions were explored to understand their effects on flood or mudflow impacts for residential buildings. The "optimum retrofit strategies" were investigated for individual buildings and building portfolios by performing benefit analyses on repair costs and times.
Results show that, while water/mud contact can cause severe damage to the interior building and content items, physical flood and mud flow load actions may cause significant damage to the exposed exterior building components. They may lead to high hazard losses and long repair times, especially for buildings with finished basements. Also, the impact models for individual buildings were found to be highly sensitive to a change in lateral resistance design, floor area, finish quality, and locations of items. While most impact models in the literature are deterministic, the developed models give reliable estimates, accounting for uncertainties associated with the critical factors. The impact models developed for building portfolios show that neglecting spatial correlation in losses and repair times due to commonality in hazard demand and building performance may underestimate the overall loss and recovery time assessments for the lower probabilities of exceedance, the region of significance for public safety and insurance underwriting purposes. Moreover, benefit analyses on retrofit actions to reduce hazard impacts show that most of these actions cannot perform adequately on their own, but if grouped together as a package, they may be more effective and useful solutions. Retrofit packages that include barriers around the building perimeter were found to be among the most effective and economic actions contributing to reductions in hazard impacts.
The researcher Dr. Deniz is currently an Asst. Professor at the host institute. During the project, the researcher was involved in several training activities to gain new skills or improve them, including training several MS and PhD students and increasing her team size. The project resulted in two conference proceedings, five and one upcoming conference presentations, three upcoming journal papers, and two panel talks. Regular posts have been placed on a website devoted to the project and other social media accounts to disseminate the project activities to the public. Moreover, several nontechnical communication activities were performed, including two presentations for MSCA candidates and three summer schools for high school students. Furthermore, through the transfer of knowledge, dissemination, and exploitation activities with representatives, the researcher has recently started one industrial collaboration to create Turkey's first-time national compulsory flood and landslide insurance premiums. She has also recently started research collaborations with colleagues at the host and other institutes. Therefore, the fellowship supported the researcher in fully integrating into the host institute. Moreover, it helped her in becoming one of the independent and leading researchers in the research area of disaster resilience.
Results show that, while water/mud contact can cause severe damage to the interior building and content items, physical flood and mud flow load actions may cause significant damage to the exposed exterior building components. They may lead to high hazard losses and long repair times, especially for buildings with finished basements. Also, the impact models for individual buildings were found to be highly sensitive to a change in lateral resistance design, floor area, finish quality, and locations of items. While most impact models in the literature are deterministic, the developed models give reliable estimates, accounting for uncertainties associated with the critical factors. The impact models developed for building portfolios show that neglecting spatial correlation in losses and repair times due to commonality in hazard demand and building performance may underestimate the overall loss and recovery time assessments for the lower probabilities of exceedance, the region of significance for public safety and insurance underwriting purposes. Moreover, benefit analyses on retrofit actions to reduce hazard impacts show that most of these actions cannot perform adequately on their own, but if grouped together as a package, they may be more effective and useful solutions. Retrofit packages that include barriers around the building perimeter were found to be among the most effective and economic actions contributing to reductions in hazard impacts.
The researcher Dr. Deniz is currently an Asst. Professor at the host institute. During the project, the researcher was involved in several training activities to gain new skills or improve them, including training several MS and PhD students and increasing her team size. The project resulted in two conference proceedings, five and one upcoming conference presentations, three upcoming journal papers, and two panel talks. Regular posts have been placed on a website devoted to the project and other social media accounts to disseminate the project activities to the public. Moreover, several nontechnical communication activities were performed, including two presentations for MSCA candidates and three summer schools for high school students. Furthermore, through the transfer of knowledge, dissemination, and exploitation activities with representatives, the researcher has recently started one industrial collaboration to create Turkey's first-time national compulsory flood and landslide insurance premiums. She has also recently started research collaborations with colleagues at the host and other institutes. Therefore, the fellowship supported the researcher in fully integrating into the host institute. Moreover, it helped her in becoming one of the independent and leading researchers in the research area of disaster resilience.
The project MulHaRes directly addresses the focus areas in Horizon 2020 Work Programme on "secure societies: security, critical infrastructure protection", "societal resilience to natural hazards," and "climate-resilient future" by developing a decision approach that aims to support multi-hazard resilience of residential buildings to floods and landslides (i.e. mudflows) provoked by heavy rainfalls. The outcomes of this study are assessed at two levels of resolution: at the local level of individual buildings versus at the level of building portfolios in a community. This study thus brings an innovative decision framework that greatly contributes to different stakeholders, including building owners seeking to mitigate their homes or to decrease their insurance premiums, reinsurance companies seeking to improve insurance portfolio risk policy, and government or research agencies seeking to improve public policy and disaster response and management plans.