Coastal flood risks in China through the 21st century – An application of DIVA.

China experiences frequent coastal flooding, with nearly US$77 billion of direct economic losses and over 7,000 fatalities reported from 1989 to 2014. Flood damages are likely to grow due to climate change induced sea-level rise and increasing exposure if no further adaptation measures are taken. This paper quantifies potential damage and adaptation costs of coastal flooding in China over the 21st Century, including the effects of sea-level rise. It develops and utilises a new, detailed coastal database of China developed within the Dynamic Interactive Vulnerability Assessment (DIVA) model framework. The refined database provides a more realistic spatial representation of coasts, with more than 2,700 coastal segments, covering 28,966 km of coastline. Over 50$ 67-3,308 billion damages/yr are projected without upgrade to defences. In contrast, maintaining the current protection level would reduce those numbers to 0.2-0.4 million people flooded/yr and US$22-60 billion/yr flood costs by 2100, with a protection investment costs of US$ 8-17 billion/yr. In 2100, maintaining current protection levels, dikes costs are two orders of magnitude smaller than flood costs across all scenarios, even without accounting for indirect damages. This research improves on earlier national assessments of China by generating a wider range of projections, based on improved datasets. The information delivered in this study will help governments, policy-makers, insurance companies and local communities in China understand risks and design appropriate strategies to adapt to increasing coastal flood risk in an uncertain world

ICSM CHC White Paper II: Impacts, vulnerability, and understanding risks of climate change for culture and heritage: Contribution of Impacts Group II to the International CoSponsored Meeting on Culture, Heritage and Climate Change

Climate change is already impacting multiple types of heritage across all regions of the world. Future climate change poses increased risks to heritage globally, including losses and damages to heritage of current and future generations and particularly severe impacts on the intangible cultural heritage of Indigenous communities. Climate change impacts on heritage are not being studied consistently nor systematically, which is reflected in heritage coverage in IPCC assessments and special reports. There is a global imbalance in the number of publications assessing the impact of climate change on heritage between different regions. Regional, national and sub-national disparities are also observed (example of Australia East vs. West). As a result, it is difficult to know if what we know about the impact of climate change on heritage is just a reflection of where the science is funded rather than where or when heritage is being affected by climate change. Impacts of climate change on the broader economic benefits (besides tourism), and social and cultural value of heritage are neither investigated nor reviewed globally and rarely explored regionally or locally. Disparities in climate change / heritage publications appear to be determined by research funding, income inequality (within and between countries), colonial legacy (research ties and relationships between former colonies and colonising countries), legal systems of heritage protection (imbalance between natural and cultural heritage depending on the country/region), local vs. international interest in heritage, the language of publication (focus on English excluding other significant scientific languages such as French, Spanish, or Japanese). Improvement of data reliability and resolution allows for more nuanced reconstructions of impacts of past climatic events, facilitating historically important factors of societal adaptation processes proportional to those changes. Yet they do not provide straightforward solutions for contemporary anthropogenic climate change as the scale of recent changes across the climate system are unprecedented over many centuries to many thousands of years. Alignment of climate change risk terms may facilitate collaboration between climate science and heritage research fields and enhance the likelihood of uptake by large climate change assessments like the IPCC. Innovative methods, especially those which are ideal for assessing social and cultural vulnerability, are needed to integrate the value of intangible cultural heritage with assessments of climate change risk. There is opportunity for climate change / heritage research to embrace transformational, inter- and transdisciplinary, and decolonial principles to address a range of the research and practice challenges as the field matures

Are master plans effective in limiting development in China's disaster-prone areas?

The effectiveness of urban master plans in limiting development in a disaster-prone area of China was empirically investigated by measuring cities’ land-cover changes against their master plans. If a master plan serves as guidance for urban polices that reduce property loss from earthquakes, floods, landslides,land subsidence, and rises in sea level, it will substantially limit urban development in areas at risk from environmental hazards. An environmental risk map weighted toward valuable forms of land cover was generated using geospatial databases of China’s Yangtze River Delta region. Based on this data, the effects of five master plan measures—ring-road patterns, block size, the area of urban built-up lands, the locations of industrial sites, and preservation zoning—were tested using the multiple regression method. Cities showing a high degree of compliance, in particular with preservation zoning, had a smaller amountof urban land located in high-risk zones, on average, by 14 km2. Among the top ten cities exposed to disproportionately high risks, eight were towns and only two were cities like Huzhou and Kunshan

Spatial modelling and GIS-based decision support tools to evaluate the suitability of sustainable aquaculture development in large catchments

Land, water and natural resources are under increasing pressure due to rising demands for food and energy from the rapidly growing global population. Across a catchment there can be multiple stakeholders with conflicting opinions over how space and resources should be used and managed. Consequently, it is important to consider the suitability of a catchment for a particular purpose to optimise use of the area and minimise potential conflicts and impacts on the wider environment. Aquaculture is a significant contributor to world food supply and as fisheries are unlikely to increase it is expected that the industry will continue to grow and expand in the future to help meet food security requirements. As a result, it is essential that the sector aims for sustainable development within the most suitable locations. However, it can be difficult to assess the suitability of multiple large catchments and some issues may not be immediately apparent. This project aimed to show how spatial models could be used as decision support tools to evaluate the suitability of large catchments for sustainable aquaculture. Four large areas of importance to aquaculture were selected; covering 10,148km2, 26,225km2, 48,319km2 and 66,283km2 in Bangladesh, China, Thailand and Vietnam respectively. Asia is by far the most dominant aquaculture region in the world and each of the four study areas contribute to local, regional and global food supplies. The study area in Bangladesh was located in Khulna region in the south west of the country and the main species of focus were prawn and shrimp. The Chinese study area was located in the south eastern province of Guangdong and the main species covered were tilapia and shrimp. Similarly, in Thailand, the main species evaluated were tilapia and shrimp whilst the study area extended across the Central region. Finally, the largest study area was the Mekong Delta in Vietnam and the main species of focus in this area were pangasius catfish and shrimp. One of the challenges in modelling large catchments is model applicability and data availability. Often, the required data are not available (or accessible) and it would be difficult, time consuming and expensive to collect new information. Furthermore, when assessing multiple areas is it vital that a representative and unbiased approach is used where no one catchment is favoured over the other due to higher quality data. Therefore, this study used data that are available for almost any area in the world; allowing future application of the models and enabling effective and unbiased decision support. Four modelling stages were employed in this study to evaluate the suitability of large catchments for sustainable aquaculture development. The first stage was the classification of seasonal land use models from satellite imagery. This provides information on what the land is used for and how aquaculture could impact or be impacted by the wider environment. The second step was the development of seasonal models of site suitability using optimal values within a GIS-based multi-stage framework. These models identify which locations are best for culture and can also be used to estimate the availability of areas for food production. The next stage investigated the use of Maxent as a novel approach in site suitability modelling to evaluate the conditions experienced by existing farms. The information from Maxent can be used to identify trends, opportunities and concerns related to sustainable management and farm locations. Finally, qualitative models of non-point source pollution (NPSP) were developed which assess the risk of NPSP within a catchment. NPSP is an issue which can impact both aquaculture and the wider environment. Thus, it is important to understand the areas within a catchment where NPSP risk is higher enabling the establishment of monitoring and/or mitigation procedures. The models support the ecosystem approach to aquaculture (EAA) and enable objective planning and management strategies to enhance productivity across large catchments without negatively impacting the environment. In order to meet growing food requirements, large areas will need to be used for agriculture and aquaculture; therefore, analysis at a wider catchment level, which complements assessment at a local scale, is required as it allows a holistic view of the situation. The work presented here illustrates the potential use of spatial models across large catchments and considers the suitability of the areas for aquaculture development

Spatiotemporal variations of tidal flat landscape patterns and driving forces in the Yangtze River Delta, China

As a crucial coastal wetland habitat in the transition zone between land and sea, global tidal flats have severely declined by 16% over the last two decades under the dual threats of intense human activities and climate change. The Yangtze River Delta of China, the largest estuary in the western Pacific Ocean, has abundant mudflat resources and a dense human population. It also has some of the most prominent conflicts between economic development and ecological conservation. The current lack of understanding of landscape patterns and influencing factors of the Yangtze River Delta mudflats has severely hampered the region’s ecological conservation and restoration efforts. Based on Landsat time-series images, this study generated a 30-m spatial resolution map of mudflats in the Yangtze River Delta, which shrank by 47% during 1990–2020, with a higher density of mudflat loss in Yancheng and Nantong cities of the Jiangsu province and Hangzhou, Shaoxing, and Ningbo cities of the Zhejiang province. Landscape indices, such as the patch density of tidal flats, have gradually changed since 2000, with most of them showing significant changes in 2010. Mudflats in Lianyungang, northwestern Yancheng, Nanhui, Jiaxing, and Hangzhou showed sharp negative changes in landscape characteristics. Natural and anthropogenic factors had synergistic effects on the above changes in mudflat landscape patterns in the Yangtze River Delta. Mudflat landscape features were mainly influenced by population growth, economic development, reclamation, sediment discharge, and air temperature. Based on the evolving characteristics of mudflat landscape patterns, we recommend improving mudflat landscape management and planning by strengthening mudflat policies, laws, and regulations, developing countermeasures against threats from major stressors, and enhancing the effectiveness of nature reserves for mudflat protection