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On 6 February 2023, two 7.8 magnitude earthquakes consecutively hit south-central Türkiye, causing great concern from all governments, the United Nations, academia, and all sectors of society. Analyses indicate that there is also a high possibility of strong earthquakes with a magnitude of 7.8 or above occurring in the western region of China in the coming years. China is a country that is highly susceptible to catastrophic disasters such as earthquakes, floods, and other natural calamities, which can cause significant damages to both human life and property, as well as widespread impacts on the society. Currently, China's capacity for disaster prevention and control is still limited. In order to effectively reduce the impact of catastrophic disasters, ensure the safety of people's lives and property to the greatest extent possible, maintain social stability in high-risk areas, and ensure high-quality and sustainable regional development, it is urgent to improve the seismic resistance level of houses and critical infrastructure in high earthquake risk zones and increase the earthquake-resistant design level of houses in high-risk fault areas with frequent seismic activities; significantly enhance the ability to defend against extreme weather and ocean disasters in economically developed areas along the southeastern coast, as well as the level of fortification in response to extreme meteorological and hydrological disasters of coastal towns/cities and key infrastructure; vigorously enhance the emergency response capacity and disaster risk prevention level in western and ethnic minority regions; comprehensively improve the defense level of residential areas and major infrastructure in high geological hazard risk zones with flash floods, landslides, and mudslides; systematically promote national disaster prevention and mitigation education; and greatly enhance the societal disaster risk reduction ability, including catastrophic insurance. [ABSTRACT FROM AUTHOR]

Droughts and heatwaves are the most detrimental climatic threats to global wheat production, their spatiotemporal coexistence (compound drought and heatwave events [CDHEs]) can cause synergistic and amplified impacts on wheat yield, which call for an improved understating of their characteristics and variations that related to wheat growth. Past decade has witnessed a surge in the study of CDHEs in terms of their causative mechanisms, variabilities and impacts; however, changes in CDHEs occurring within crops' growing seasons are barely discussed, especially on global scale. In this study, we proposed a novel approach to identify and summarize CDHEs by taking "crop growing season" as accumulated period, and investigated the spatiotemporal changes of CDHEs occurring within wheat growing seasons over global wheat‐producing areas during 1981–2020, including their spatial extent, frequency and duration. Results show that the spatial extent of CDHEs experienced rapid expansion during wheat growing seasons of 1981–2020, meanwhile, droughts and heatwaves increasingly tended to occur simultaneously. More than 92% of wheat‐producing areas experienced at least one CDHE in each wheat growing season, the frequency of CDHEs increased significantly in 28.2% of wheat‐producing areas, and the total duration of CDHEs increased significantly in 33.2% of wheat‐producing areas. Europe, eastern China, western US and northern Argentina are the hotspot regions with the biggest contradiction between fast‐increasing CDHEs and wheat production, pointing to the urgency of marking spatially targeted adaptation measures for disaster reduction and risk management. [ABSTRACT FROM AUTHOR]

In this article, we recall the United Nations' 30-year journey in disaster risk reduction strategy and framework, review the latest progress and key scientific and technological questions related to the United Nations disaster risk reduction initiatives, and summarize the framework and contents of disaster risk science research. The object of disaster risk science research is the "disaster system" consisting of hazard, the geographical environment, and exposed units, with features of regionality, interconnectedness, coupling, and complexity. Environmental stability, hazard threat, and socioeconomic vulnerability together determine the way that disasters are formed, establish the spatial extent of disaster impact, and generate the scale of losses. In the formation of a disaster, a conducive environment is the prerequisite, a hazard is the necessary condition, and socioeconomic exposure is the sufficient condition. The geographical environment affects local hazard intensity and therefore can change the pattern of loss distribution. Regional multi-hazard, disaster chain, and disaster compound could induce complex impacts, amplifying or attenuating hazard intensity and changing the scope of affected areas. In the light of research progress, particularly in the context of China, we propose a three-layer disaster risk science disciplinary structure, which contains three pillars (disaster science, disaster technology, and disaster governance), nine core areas, and 27 research fields. Based on these elements, we discuss the frontiers in disaster risk science research. [ABSTRACT FROM AUTHOR]

The extent of economic losses due to a natural hazard and disaster depends largely on the spatial distribution of asset values in relation to the hazard intensity distribution within the affected area. Given that statistical data on asset value are collected by administrative units in China, generating spatially explicit asset exposure maps remains a key challenge for rapid postdisaster economic loss assessment. The goal of this study is to introduce a top-down (or downscaling) approach to disaggregate administrative-unit level asset value to grid-cell level. To do so, finding the highly correlated 'surrogate' indicators is the key. A combination of three data sets-nighttime light grid, LandScan population grid, and road density grid, is used as ancillary asset density distribution information for spatializing the asset value. As a result, a high spatial resolution asset value map of China for 2015 is generated. The spatial data set contains aggregated economic value at risk at 30 arc-second spatial resolution. Accuracy of the spatial disaggregation reflects redistribution errors introduced by the disaggregation process as well as errors from the original ancillary data sets. The overall accuracy of the results proves to be promising. The example of using the developed disaggregated asset value map in exposure assessment of watersheds demonstrates that the data set offers immense analytical flexibility for overlay analysis according to the hazard extent. This product will help current efforts to analyze spatial characteristics of exposure and to uncover the contributions of both physical and social drivers of natural hazard and disaster across space and time. [ABSTRACT FROM AUTHOR]

Risk assessment plays an important role in disaster risk management. Existing multi-hazard risk assessment models are often qualitative or semi-quantitative in nature and used for comparative study of regional risk levels. They cannot estimate directly probability of disaster losses from the joint impact of several hazards. In this paper, a quantitative approach of multi-hazard risk assessment based on vulnerability surface and joint return period of hazards is put forward to assess the risk of crop losses in the Yangtze River Delta region of China. The impact of strong wind and flood, the two most prominent agricultural hazards in the area, is analyzed. The multi-hazard risk assessment process consists of three steps. First, a vulnerability surface, which denotes the functional relationship between the intensity of the hazards and disaster losses, was built using the crop losses data for losses caused by strong wind and flood in the recent 30 years. Second, the joint probability distribution of strong wind and flood was established using the copula functions. Finally, risk curves that show the probability of crop losses in this multi-hazard context at four case study sites were calculated according to the joint return period of hazards and the vulnerability surface. The risk assessment result of crop losses provides a useful reference for governments and insurance companies to formulate agricultural development plans and analyze the market of agricultural insurance. The multi-hazard risk assessment method developed in this paper can also be used to quantitatively assess multi-hazard risk in other regions. [ABSTRACT FROM AUTHOR]

The increasingly globalized and networked world coupled with enlarging spatial scope and severity of natural and man-made hazards are leading to significant cross-boundary impacts. It has not been adequately addressed that how those impacts transmit from one (sub-) system/network to another and how the socioeconomic systems respond. This paper examines the impact of the global economic crisis and the Tohoku earthquake on Sino-Japan trade based on trade data released by the Japanese Ministry of Finance. Our time series analysis model shows that in the short term, the economic crisis has an impact of 66 % larger than that of the earthquake. The impact of economic crisis is more acute and deep due to the collapse of consumers' and investors' confidence, but for the earthquake, it is more gradual as the impact spreads via production chain and supply chain across industries and regions. The pattern implies critical difference in disaster risk reduction strategies for the two types of catastrophes. [ABSTRACT FROM AUTHOR]

This study, based on a questionnaire survey and workshops, and with a focus on the impact of an earthquake on the Nagata Elementary School Community in Kobe City, Japan, develops a collaborative model to assess the allocation of residents to shelters. The current official allocation plan is compared with three alternative allocations developed within the framework of this model. The collaborative model identifies accessibility, amenity, capacity, connectivity, continuity, security, and stability as the basic, necessary criteria for shelter planning. The three alternative allocations are very similar to the local residents' own choice of shelters, but they are quite different from the current official allocation plan, which is supposed to be followed but has achieved relatively low satisfaction among households. The proposed collaborative approach provides an effective tool to assess the officially determined allocation plan by taking into account the viewpoints of local residents, and the results are useful for enhancing community evacuation planning. [ABSTRACT FROM AUTHOR]

Disaster loss estimates are helpful for managing post-disaster reconstruction and for designing disaster-risk mitigation strategies. However, most of these estimates in China merely consider direct losses, and only a few include indirect economic losses. As the most destructive earthquake since the founding of the People's Republic of China in 1949, the Wenchuan Earthquake that occurred in 2008 resulted in direct economic damages reached Chinese Yuan (CNY) 845 billion (US $124 billion). The aim of the study was to estimate indirect economic losses caused by the Wenchuan Earthquake in Sichuan Province through the Adaptive Regional Input-Output (ARIO) model, which can reflect disaster-related changes in production capacity, ripple effects within the economic system, and adaptive behaviors of economic actors. The results showed that indirect economic losses in the production and housing sectors were estimated at 40% of the direct economic losses, i.e., approximately CNY 300 billion; moreover, the model predicted an 8-year reconstruction period. Several factors contributed to these losses, including significant damages to key sectors, financial constraints on reconstruction, post-earthquake investment instability, and limits in reconstruction capacity. Active government support policies post-earthquake are a useful strategy to mitigate the adverse economic impact of an earthquake in developing countries. [ABSTRACT FROM AUTHOR]