title: Incorporating ecosystem services in a multi-hazard risk assessment framework to inform disaster risk reduction and climate change adaptation in coastal river deltas
Creators: name: Peng, Yuting
Publisher: name: University of Glasgow
Year: 2024

description: Coastal river deltas face increased exposure, vulnerability and risks linked to multiple natural hazards, stemming from the interplay of often linked factors such as higher population densities, rapid urbanization, low-lying topography, land subsidence and global climate change impacts. Enhancing our ability to respond to the impacts of climate change, while promoting strategies for risk reduction and adaptation, have garnered global attention. Essential to this effort are vulnerability and risk assessments, critical for mapping, managing and reducing risks and concurrently contributing to sustainable development.

In-depth exploration of climate change impacts in deltaic landscapes and of the theoretical and methodological evolution in assessing vulnerability and risks has highlighted the evolving landscape of risk assessment methodologies, including shifts (1) to consider socio-ecological systems as starting points of analyses, (2) from single to multi-hazard risk assessments, and (3) considering the role of ecosystem services to address climate change adaptation and risk reduction concerns. Current vulnerability and risk assessments focus primarily on social aspects, and often neglect the balanced incorporation of a socio-ecological systems perspective, potentially resulting in incomplete assessments. Hence, addressing this scientific gap in this research involves incorporating the role of ecosystem services into vulnerability and risk assessments, emphasizing the overall principle of ecosystem services as a bridge connecting socioeconomic and biophysical systems.

Building on existing vulnerability and risk assessment frameworks, a revised indicator-based framework for deltaic social-ecological systems is proposed in addition to a list of ecosystem service indicators identified via literature review. Ecosystem service indicators, which capture the intricate interactions between human society and natural environments, can be used to better characterize the mutual dependencies between social and ecosystem vulnerability. This enhanced framework stands as an effective tool to determine the vulnerability and risk of coastal deltas, facilitating the assessment of multi-hazard risks within and across deltas, and allowing targeted ecosystem-based adaptation measures and policies.

In conjunction with the development of a comprehensive risk assessment framework, this study implements the approach alongside a modular indicator library in capturing the muti-hazard risk characteristics of all cities in the Pearl River Delta (PRD) and the Yangtze River Delta (YRD) regions in China. For each region, expert consultations were conducted to enhance the understanding of the study sites and determine the final indicator list and their weighting assignments. Comparative analyses show a higher risk level in the PRD, predominantly concentrated along its coastal zones. Even though risk levels may appear similar, key drivers of risk sub-components vary at different spatial scales. Ecosystem services have been identified as important factors explaining the risk profiles of the deltas’ cities, underscoring the importance of their inclusion into strategies aimed at disaster risk reduction and climate change adaptation.

The research further compares two risk assessment frameworks that comprehensively incorporate both social and ecological dimensions in order to analyse differences in regional vulnerability and risk levels caused by different risk components within the deltas. The newly proposed framework enables the identification of key ecosystem services and priority regions related to disaster risk and establishes their linkages with existing ecosystem-based adaptation (EbA) practices and global/national policies, thus promoting EbA success in vulnerable regions exposed to natural hazards.

This study used a mixed quantitative and qualitative approach to map the risk distribution in two large deltas, aiming to visualize hazard-prone and highly vulnerable areas and differentiate priority regions for EbA implementation. Different weighting assignment methods and assessment frameworks are compared in practice to reduce results uncertainty. The proposed risk assessment framework allowed clarifying (multi-)hazard risk components and can be easily adjusted from the delta scale down to the regional/community scale. Future development of down-scale and ecosystem-specific EbA initiatives requires more accurate and locally relevant data. In this context, future research calls on the academic and all levels of government to address data scarcity, improve cross-disciplinary knowledge integration, and enhance the participation of local sectors and communities.