Giovinazzi ECEE 21March 2018
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FOSTERING THE RESILIENCE OF HERITAGE BUILDINGS IN NEW ZEALAND: POTENTIALITIES OF DECISION SUPPORT SYSTEMS Sonia GIOVINAZZI1, Shannon ABELING2, Francisco GALVEZ2, Stacy VALLIS23, Tatiana GODED4, Nick HORSPOOL5, Elena CALANDRA6, Jason INGHAM7 ABSTRACT The 2010-2011 Canterbury earthquake sequence (CES) in New Zealand, and further recent earthquake events worldwide, has shown the invaluable loss that earthquakes can cause to architectural heritage. This paper explores the potentiality and the extent to which Decision Support Systems (DSSs) might have on informing the decision- making processes towards thriving the resilience of heritage buildings to natural hazards, with special focus on earthquakes. In particular, in the paper, reference is made to RiskScape, the New Zealand DSS platform for assessing the risks from natural hazards, where the possibility to assess the seismic vulnerability of heritage buildings and to prove the effectiveness of different mitigation options, at territorial scale, has been already embedded, as far as churches are concerned. The idea would be to include further add-ins to RiskScape to contribute towards an ambitious initiative aiming to enhance the seismic resilience of heritage buildings in New Zealand. In this paper, the idea to include in RiskScape, as a first step, a database to foster the awareness of stakeholders and communities on their Cultural Heritage at risk, is firstly discuss. The already embedded RiskScape add-in that allows performing scenario analysis at territorial scale to assess direct and indirect impacts is then illustrated. Finally, a further add-in that enables the analysis at single building level to identify the most likely collapse mechanisms is illustrated. This could support the identification of effective mitigation strategies pre-event and of emergency management and repair/reconstruction strategies, post-event. Keywords: Cultural Heritage; Resilience; Decision Support Systems; Seismic Vulnerability; Retrofitting Strategies. 1. INTRODUCTION There is a unanimous agreement on the criticality and urgency to collaboratively work to foster the resilience of cultural heritage, including tangible and intangible, moveable and immovable items, since they are increasingly affected by both natural and human-made threats and since the conservation of cultural heritage, is critical for sustainable and stable development of societies. Cultural heritage supports, among others, cultural identity and wellbeing of communities as well as local economy and economic growth; also, the cultural diversity that cultural heritage embodies, contributes to the resilience of social systems as it is the result of centuries of slow adaptation to the hazards that affect local environments. Unfortunately, in all regions of the world and for all types of cultural heritage there is, at the time being, a very low level of awareness and preparedness in regard to disaster risks that might potentially affect cultural heritage, and an almost total lack of inclusion of cultural heritage in general 1Senior Research Fellow, Geospatial Research Institute, University of Canterbury, Christchurch, New Zealand, [email protected] 2 PhD candidate, Department of Civil and Environmental Engineering, University of Auckland, 1023 Auckland. 3 PhD candidate, School of Architecture and Planning, University of Auckland, 1010 Auckland 4Seismic Hazard Modeller, GNS Science, Avalon, New Zealand, [email protected] 5Risk Specialist, GNS Science, Avalon, New Zealand, [email protected] 6Director, Istituto Centrale per l'Archeologia - MiBACT, Rome, Italy 7Professor, Department of Civil and Environmental Engineering, University of Auckland, Auckland, New Zealand, [email protected] disaster risk management strategies and plans8 The 2010-2011 Canterbury earthquake sequence (CES) in New Zealand and further recent earthquake events worldwide have shown the invaluable loss that earthquakes can cause to architectural heritage. In particular, the CES resulted in the loss of invaluable local architectural heritage, as a number of unreinforced masonry buildings, having significant historic, architectural, and social importance, and recognized as “historic places” by Heritage New Zealand (2018) were demolished instead of undergoing repair (Figure 1). In the aftermath of the CES9 BlueShield released a statement reminding that “In addition to the tragic loss of human lives and the country’s prevailing state of shock, the loss of significant aspects of Christchurch’s heritage will have profound and lasting consequences on the self-conception and the collective memory of its inhabitants. The intangible values of a people’s cultural heritage can support the processes to regenerate normality and help people to move forward. Cultural heritage is a fundamental aspect in the rebuilding of community identity and dignity, as well as in keeping up hope after such a catastrophe. The Blue Shield trusts that the emergency authorities will take appropriate measures to ensure the preservation of heritage features of the city in the aftermath of the disaster’’. Several efforts were taken to preserve the heritage features of the city as envisaged by the BlueShield; but, unfortunately, the lack of prevention and, the idea that repair and reconstruction was not feasible, not-economically viable, and that in any case could not bring some unreinforced masonry (URM) buildings to an acceptable safety standard level were, among others, the reasons that supported the demolitions of some heritage buildings (Heritage New Zealand, 2018). Christchurch City Cathedral, iconic symbol of Christchurch City, only recently escaped the same fate, thanks also to the strong opposition of community groups that fought against the demolition decision originally took by the owner of the Cathedral and supported by the Government10. c) a) b) Figure 1. Examples of cultural Heritage lost after the CES (pictures courtesy of Heritage New Zealand 2018): a) The Press building”, Category 1 historic place- Demolished 2011; b) Cranmer Court (former Normal School), Category 1 historic place - Demolished 2012; c) Cranmer Centre (former Christchurch Girls High School), Category 1 historic place - Demolished 2011, Architecturally it was significant as a fine example of Victorian school architecture in a Venetian Gothic style. Historically it was identified with the development of women's education in New Zealand as housed, for over 100 years, the first public girls' school in Christchurch. To increase the awareness of the risk affecting cultural heritage and on the dutiful need and possibility to protect the cultural heritage pre-event and/or to undertake repair and reconstruction actions the national and international scientific community joined forces and promoted several initiatives in New- Zealand. In particular, the same authors collaborated on the project “Vulnerability Analysis of Unreinforced Masonry Churches” funded by the New Zealand Earthquake Commission EQC, which moved the first step towards the seismic protection and preservation of historical buildings in New 8 https://www.unisdr.org/archive/53456 9 https://www.icomos.org/110303_ICBS_Statement_Christchurch_EN.pdf 10 http://restorechristchurchcathedral.co.nz/ 2 Zealand (Godet et al. 2016). Extending upon that earlier project, the authors worked on the project “An- operational framework to determine the seismic resilience of New Zealand churches” funded by QuakeCoRE, the New Zealand Centre for Earthquake Resilience. Building on the aforementioned work, this paper would like to explore the possibility to create in New Zealand a Decision Support System (DSS) that could inform and support the decision-making process for understanding disaster risk and mitigating impacts on heritage buildings, therefore enhancing their resilience. DSSs include a wide range of computer-based tools that have specific simulation and prediction capabilities and are usually developed to support decision analysis and participatory processes. DSSs are also used as a vehicle of communication, training and experimentation, as DSSs facilitate dialogue and exchange of information thus providing insights to non-experts and supporting them in the exploration of policy options. In particular, DSSs and platforms for the prediction of risks and losses from natural hazards consist of different databases, coupled with hazard prediction/monitor capabilities, and ad-hoc modules for the exposure and vulnerability assessment, along with modules for socio-economic impact assessment; DSSs are, usually, provided with a dedicated interface in order to be directly and more easily accessible by policy and decision makers, stakeholders, the wider community, etc.. There are several already existing DSSs that aim to support the assessment of risks from a multi-hazard perspective and to inform and support decision-making processes for mitigation, recovery rehabilitation and reconstruction (an overview of available open-source DSSs for assessing multi-hazard risks is provided by the Global Forum for Disaster Risk Reduction, GFDRR11). However, as far as the knowledge of the authors is concerned, not many, if none of such DSSs, have included heritage buildings as part of the assets under analysis. This paper, in accordance with the priorities identified by the Sendai Framework for Disaster Risk Reduction, 2015-203012, aims to explore the potentialities of using DDSs for enhancing the resilience of heritage buildings. In particular, reference is made to an existing