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On 20 July 2021, an extreme rainstorm battered Zhengzhou in China's Henan Province, killing 302 people, including 14 individuals who drowned in a subway tunnel and 6 who drowned in a road tunnel. As the global climate warms, extreme weather events similar to the Zhengzhou flood will become more frequent, with increasingly catastrophic consequences for society. Taking a case study-based approach by focusing on the record-breaking Zhengzhou flood, this paper examines the governance capacity of inland cities in North China for managing extreme precipitation and flooding events from the perspective of the flood risk management process. Based on in-depth case analysis, our paper hypothesizes that inland cities in North China still have low risk perceptions of extreme weather events, which was manifested in insufficient pre-disaster preparation and prevention, poor risk communication, and slow emergency response. Accordingly, it is recommended that inland cities update their risk perceptions of extreme rainfall and flooding events, which are no longer low-probability, high-impact "black swans", but turning into high-probability, high-impact "gray rhinos." In particular, cities must make sufficient preparation for extreme weather events by revising contingency plans and strengthening their implementation, improving risk communication of meteorological warnings, and synchronizing emergency response with meteorological warnings. [ABSTRACT FROM AUTHOR]

In light of the challenges posed by climate change and rural revitalization, high-quality construction in rural areas is facing significant obstacles from rainstorm flooding. This study adopts a regional disaster system analysis framework and examines the characteristics of rural rainstorm flooding disasters, including the instability of the breeding environment, the hazard characteristics, and the vulnerability of the exposure. Using this framework, we explore the various causes of rainstorm flooding in rural China, assess the effectiveness of responses to these disasters, and examine the differences between urban and rural responses. Our analysis reveals that the increase in rainstorm flooding in rural China is a complex result of multiple factors, including increased risk, instability, and vulnerability. While rural areas have made some progress in monitoring and responding to rainstorm flooding disasters, they remain weaker than cities in terms of governance and disaster management systems. To address these challenges, we recommend increased attention to rural flood control and disaster reduction, stronger preparation for disaster prevention and reduction plans, enhanced rural disaster infrastructure defense, increased financial support for water conservancy projects, and stronger professional emergency response teams, disaster relief equipment, and materials. Additionally, we recommend strengthening disaster prevention and reduction education and publicity among rural residents to promote the ability to self-rescue and mutual rescue. The disastrous impact of climate change and resulting extreme weather events on rural areas has become increasingly evident in recent years. China's vast rural areas have been particularly affected by frequent rainstorm flooding disasters. This paper identifies the increase in rainstorms, the instability of the disaster breeding environment in rural areas, and the increased vulnerability of exposures in these areas as the main reasons behind the intensification of rural rainstorm flooding. To mitigate the impact of these disasters, attention should be paid to natural disaster risk management, normalized flood control, and disaster reduction in rural areas. This requires overall coordination of rural disaster prevention and reduction planning, emphasis on improving the defense capacity of rural areas, increasing financial support for defensive water conservancy projects, promoting the construction of professional emergency rescue teams in rural areas, scientifically distributing flood prevention and disaster relief equipment and materials, strengthening publicity and education on disaster prevention and reduction, and enhancing rural disaster prevention awareness and self-rescue and mutual rescue capabilities. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to strengthen research concerning the impact of climate change on China's water resources, in order to avoid extreme weather events such as regional rainstorms and floods affecting the stable supply of energy and electricity. The goal is to reorganize energy industry allocation to make China's energy the most efficient, which would thus help achieve sustainable development goals. The biggest contribution and of this paper is not only to enlarge the scale and take into account the sustainable aspects, but also to consider climate change factors that have been ignored in the past as exogenous variables. For the first time, we take stock of the optimal allocation of new and tradition energy sources and carbon dioxide. This study uses the Dynamic ZSG-DDF model with exogenous variables and undesirable outputs to find a way to redistribute carbon dioxide, new energy, and tradition energy from different provinces on the premise of maximizing efficiency, thus achieving the goal of reducing carbon and saving the earth. The research results show that the energy efficiency of tradition energy is higher than that of new energy in various provinces. At the same time, the China government must comprehensively review the quota targets of new energy, tradition energy, and carbon dioxide (CO2) in each province as quickly as possible. Currently, the quotas of various provinces are seriously misplaced, and 26 provinces in total have great room for improvement. [ABSTRACT FROM AUTHOR]

Building a more resilient response system to climate change for sustainable development and reducing uncertainty in China's food markets, requires access to historical research gaps and mapping future research progress for decision making. However, the lack of quantitative and objective analyses to ensure the stability and development of agroecosystems increases the complexity of agro-climatic mechanisms, which leads to uncertainty and undesirable consequences. In this paper, we review the characteristics of climate change in China (1951–2020), reveal the mechanisms of agroecosystem structure in response to climate, and identify challenges and opportunities for future efforts in the context of research progress. The aim is to improve the scientific validity and relevance of future research by clarifying agro-climatic response mechanisms. The results show that surface temperature, precipitation, and frequency of extreme weather events have increased to varying degrees in major agricultural regions of China in 1951–2020. And they have strong geographic variation, which has resulted in droughts in the north and floods in the south. Moreover, climate change has complicated the mechanisms of soil moisture, Net Primary Productivity (NPP), soil carbon pool, and crop pest structure in agroecosystems. This lends to a reduction in soil water holding capacity, NPP, soil carbon content, and the number of natural enemies of diseases and insects, which in turn affects crop yields. However, human interventions can mitigate the deterioration of these factors. We have also realized that the methodology and theory of historical research poses a great challenge to future agroecosystem. Historical and projected climate trends identified current gaps in interdisciplinary integration and multidisciplinary research required to manage diverse spatio-temporal climate change impacts on agroecosystems. Future efforts should highlight integrated management and decision making, multidisciplinary big data coupling, and numerical simulations to ensure sustainable agricultural development, ecological security, and food security in China. [ABSTRACT FROM AUTHOR]

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This paper investigates the relationship between extreme temperature and online complaints to local government officials. We show that the number of complaints significantly increases by 11.1% on extremely hot days relative to the benchmark temperature. Such effect is most pronounced on the day of extreme weather conditions and muted immediately after the extreme weather day. Among all the complaint areas, we find that 28.6% of the increase in complaints on hot days is related to public service, 42.8% to urban construction, 21.4% to noise, and 7.2% to safety. Moreover, we reveal that the primary motivators of increased complaints on hot days are not likely to be psychological factors; instead, the complaints are more likely to be associated with inadequate provision of public facilities to cope with extreme weather and inadequate management of other environmental disamenities caused by extreme temperature. [ABSTRACT FROM AUTHOR]

In recent years, extreme weather events caused by global climate change have occurred frequently, intensifying the frequency of flood disasters. For flood hazard analysis, high-quality data and a reasonable weight assignment of the relevant factors are critical. This study conducts four rainfall fusion methods, to fuse the Tropical Rainfall Measuring Mission (TRMM) 3B42 and the observations in Dazhou City, China. Then, the random forest was applied to obtain the weights of various factors to facilitate a comprehensive flood hazard analysis under four rainfall durations. The results show that (1) the linear regression performs best out of the four fusion methods, with a correlation coefficient of 0.56; (2) the Digital Elevation Model (DEM) is the most impact factor with a weight of more than 0.2; and (3) the proposed flood analysis system performs well, as 70% of historical flood points are distributed in high and sub-high hazard areas and more than 93% of historical flood points are distributed in medium hazard areas. This study identified the flood hazard grade and distribution in Dazhou City, which could provide a valuable methodology to contribute to flood hazard analysis and disaster management with satellite rainfall. Furthermore, the results of this paper are profound for future work on the high-resolution flood risk assessment and management in Dazhou City. [ABSTRACT FROM AUTHOR]

Climate change is having a significant impact on farmers and agriculture. Rising temperatures and extreme weather events, such as droughts and floods, are causing crop failures and reducing yields. This study evaluated existing publications from 2006 to 2022, using the Web of Science database, Citespace, and the Bibliometrix package in R language for a systematic analysis. A total of 426 publications were identified, written by 1449 authors from 56 countries. The results showed that China has the highest share of publications (16.4%), followed by the United States (14.3%) and Australia (6.8%), with China and Pakistan collaborating most frequently. The keyword timeline analysis from 2006 to 2022 identified 11 clusters of research topics related to farmers' climate change risk (CCRF). Cluster #1, "water conservation measures," had the longest duration, highlighting its significance. Key areas of CCRF research include the vulnerability of land-lost farmers, farmers' use of meteorological information, sources of risk, barriers to implementing conservation agriculture, farmers' attitudes towards heavy metal pollution, and the use of protection motivation theory in agricultural adaptation. In conclusion, climate change poses significant threats to farmers, impacting crop yields, soil fertility, and water availability. Farmers adopt adaptation strategies, but effectiveness varies due to resource limitations and policy gaps. The research on farmer adaptation to climate change is growing, emphasizing the need for supportive policies, resources, and knowledge-sharing to achieve sustainable agriculture and food security. [ABSTRACT FROM AUTHOR]

The intensification of global climate change has led to a widespread consensus on carbon reduction, with the power industry being the principal contributor to carbon emissions necessitating an inevitable transition of its energy structure. Concomitantly, the escalating frequency of natural disasters caused by extreme weather presents formidable challenges to both secure power supply and the low-carbon transition of the power system. To fulfill the developmental requirements of a low-carbon power system and address the carbon emission risks imposed by natural disasters, this paper proposes a bi-level model for generation expansion planning (GEP) that incorporates constraints on the carbon emission trajectory and the influence of natural disasters. The planning-level model optimizes investment costs of various generation technologies and energy storage (ES), as well as the overall operational expenses over the planning period, with an objective to minimize them. It incorporates carbon emission trajectory constraints and policy constraints, such as carbon peaking, carbon neutrality and renewable energy (RE) penetration rates, in order to optimize the planning installed capacity of power sources. The operational-level model aims to minimize typical daily operating costs while also simulating power unit outputs in routine and disaster scenarios. A case study is conducted in a disaster-prone province in southern China to analyze the power generation expansion planning and the trajectory of carbon emissions from 2020 to 2060 under different scenarios. The simulation results show that compared to thermal power, the planning scheme mainly focused on RE with ES is better suited to achieve the goal of a low-carbon transition of the power grid. Moreover, after considering natural disasters, the cost and carbon emissions of power system planning are higher, and the risk of carbon emissions increases with the severity of disasters. • A multi-time scale bi-level low-carbon GEP model is proposed. • Natural disaster scenarios and low-carbon policy constraints are considered in the GEP model. • Carbon emission trajectory of the planned power system is estimated and introduced as a constraint into the GEP model. • Evaluation indicators that comprehensively consider low-carbon performance and economic feasibility are proposed. [ABSTRACT FROM AUTHOR]

Semiarid regions play a pivotal role in global ecosystem and environmental governance. Changing environment (climate and land use variation) has led to the disruption of hydrology in semi-arid regions and ecological degradation in some area. Understanding their hydrological response to changing environments is crucial for ecological rehabilitation and optimal water resource allocation. This research, conducted in a Chinese semiarid watershed, integrates multi-field models about hydrology, meteorology and geography to investigate hydrological processes in typical hydrological years. The results indicate that the climate in this region is drying, and the likelihood of extreme weather events is increasing with global warming. Projecting changes from 2010 to 2060, 9.21% of grassland converting to 5.63% of forest and 3.58% of gully built-up land. As a result, the flood peak increases by 22.99% in typical drought years, while it decreases by 36.77% in normal years. Based on our analysis of the rainfallrunoff process in typical drought and normal years, we identify two distinct effects: the "local rainfall-runoff effect" and the "global rainfall-runoff effect", respectively. However, in typical wet years, the streamflow state is primarily controlled by intense and concentrated precipitation. This research provides insights into the effect of ecological restoration and typical climate variations on hydrological cycle in semiarid regions, thus contributing to more informed decision-making in environmental management and water resource planning. [ABSTRACT FROM AUTHOR]

• Extreme temperatures lead to an increase in local fiscal pressure. • Areas with intensive agriculture and low power consumption are more sensitive. • Productivity, population mobility, and power supply are the main mechanisms. • PMC reform mitigated the fiscal revenue loss and increased fiscal expenditure. This paper investigates the impact of climate change on government fiscal pressure using local governments' fiscal data in China from 2000 to 2020. While previous studies have extensively explored the effects of climate change on individuals and economies, there has been limited research on the negative effects of climate change from a government fiscal perspective. Our study makes contributions by using county-level fiscal data in China, allowing for a detailed examination of the fiscal implications of weather extremes. Moreover, we comprehensively analyze the underlying mechanisms involving population mobility, industrial structure, and electricity consumption. The empirical results indicate that each additional day of extreme temperature in a year leads to a CNY 0.002 billion increase in the general public budget deficit, which is equivalent to 0.1093% of the local fiscal deficit. Furthermore, local governments heavily reliant on agriculture, experiencing low electricity consumption, and significant population outflows face even greater challenges. Notably, medical insurance and the "province-managing-county" reform program emerge as crucial mitigating factors against fiscal pressures. By providing a thorough assessment of climate change's fiscal impact on local governments, this research contributes to the theoretical foundation for governmental initiatives aimed at reducing carbon emissions. [ABSTRACT FROM AUTHOR]

Recent studies on China's arid and semi-arid regions, particularly the Tarim River Basin (TRB), have shown an increase in the intensity and frequency of extreme weather events. This research examines the link between meteorological droughts, as measured by the Standardized Precipitation Evapotranspiration Index (SPEI), and hydrological droughts, as indicated by the Standardized Runoff Index (SRI) and the Standardized Terrestrial Water Storage Index (STI), over various time scales. Historical data indicate that SPEI drought frequency (DF) was 14.3–21.9%, with prevalent events in the northern oases. SRI DF ranged from 9.0% to 35.8%, concentrated around the Taklamakan and Kumtag Deserts, while STI DF varied between 4.4% and 32.7%, averaging 15% basin-wide. Future projections show an increased DF of SPEI in deserts and a decrease in oases; SRI DF decreased in deserts but increased in oases. STI changes were more moderate. The study also found a higher risk of drought progression from SPEI to SRI in the southwestern and northeastern oases, exceeding 50% probability, while central and eastern TRB had lower risks. The western TRB and inner Taklamakan Desert faced higher risks of SPEI to STI progression, with probabilities over 45%, in contrast to the lower risks in the eastern and central oases. The concurrence of SRI/STI with moderate to extreme SPEI droughts led to a higher probability and area of SRI/STI droughts, whereas consistent SPEI types showed a reduced induced probability and extent of SRI/STI droughts. This study enhances the understanding of drought propagation from meteorological to hydrological droughts in the TRB and contributes to the prevention of hydrological drought to a certain extent. [ABSTRACT FROM AUTHOR]

Spatial planning is broadly acknowledged for its pivotal role in local climate change adaptation. Nevertheless, variations persist among countries in their perceptions and practices concerning the effectiveness and feasibility of utilizing spatial planning for climate change adaptation. Chinese cities confront the challenges of global warming, rapid urbanization, and intensified extreme weather events. Climate change adaptation agreements, frameworks, and policies have predominantly emphasized the national scale, often overlooking local adaptation efforts. However, the ongoing reform and restructuring of China's territorial and spatial planning system encompasses the categorization, hierarchical management, control of comprehensive national land resource development, and conservation. This process is gradually establishing spatial planning strategies that synergize with the impacts of climate change, thereby offering an opportunity to integrate climate change adaptation objectives into spatial planning. This endeavor is supported by a series of regulatory standards and guidelines to ensure its effective implementation. The study scrutinizes the public draft of territorial and spatial master plans for 368 Chinese cities to assess the integration of climate change concerns at the local level and to identify disparities among cities. Employing the Awareness, Analysis, and Action Framework (3A Framework), which draws from prior scholarship and integrates relevant existing research, we identified and assessed 30 criteria for recognizing and appraising climate change adaptation strategies in territorial and spatial planning. The study's findings indicate that: (1) The role of territorial and spatial planning in integrating climate change issues at the city level requires enhancement, as reflected in the generally low "awareness" of climate change concerns, limited "analytical capacity" regarding climate change, and a certain foundation for "action response" to climate change adaptation; (2) Large cities, characterized by robust economies and population concentrations, generally outperform small and medium-sized cities. They exhibit a superior ability to delineate quantifiable climate adaptation indicators and measures. In conclusion, the study provides prospective recommendations concerning technical approaches, spatial governance, mechanisms, and actions to more effectively incorporate climate change adaptation objectives into local-level territorial and spatial planning. [ABSTRACT FROM AUTHOR]

This paper presents projected changes in temperature and precipitation extremes in China by the end of the twenty-first century based on the Coupled Model Intercomparison Project phase 5 (CMIP5) simulations. The temporal changes and their spatial patterns in the Expert Team on Climate Change Detection and Indices (ETCCDI) indices under the RCP4.5 and RCP8.5 emission scenarios are analyzed. Compared to the reference period 1986-2005, substantial changes are projected in temperature and precipitation extremes under both emission scenarios. These changes include a decrease in cold extremes, an increase in warm extremes, and an intensification of precipitation extremes. The intermodel spread in the projection increases with time, with wider spread under RCP8.5 than RCP4.5 for most indices, especially at the subregional scale. The difference in the projected changes under the two RCPs begins to emerge in the 2040s. Analyses based on the mixed-effects analysis of variance (ANOVA) model indicate that by the end of the twenty-first century, at the national scale, the dominant contributor to the projection uncertainty of most temperature-based indices, and some precipitation extremes [including maximum 1-day precipitation (RX1day) and maximum 5-day precipitation (RX5day), and total extremely wet day total amount (R95p)], is the difference in emission scenarios. By the end of the twenty-first century, model uncertainty is the dominant factor at the regional scale and for the other indices. Natural variability can also play very important role. [ABSTRACT FROM AUTHOR]

Extreme weather exerts a huge impact on human beings and it is of vital importance to study the regular pattern of meteorological and hydrological factors. In this paper, a selection of seven extreme indices is used to analyze the trend of precipitation extremes of 18 meteorological stations located in Zhejiang Province, east China using the Mann-Kendall test. Then the precipitation trends in the plum season (from May to July) and typhoon season (from August to October) are studied separately. The results show that the precipitation trend varies from east to west. There is a positive trend in the east and a negative one in the west. The largest part of Zhejiang Province shows a positive trend in heavy precipitation and the most significant upward trend is detected in Dinghai with 3.4 mm/year for precipitation on very wet days. Although the upward trend of extreme precipitation is not prevailing, the range of increase in specific areas is apparent, like Dinghai with 1.3 mm/year. Precipitation intensity exhibits an upward trend in most areas and a typical upward trend can be found in Dachendao, Tianmushan, and Yuhuan with 0.04, 0.02, and 0.05 mm/year respectively. Precipitation intensity in both plum and typhoon seasons has increased too, especially for the coastal stations. [ABSTRACT FROM AUTHOR]

Extreme weather events and anthropogenic activity have severely impacted the Minjiang estuary (MJE) with evolution patterns in recent decades. Determining the estuarine alluvial evolution pattern is crucial for the sustainable development of densely populated coastal areas. Using chart data, this paper analyzed how the MJE's flushing and siltation changed over time (1950–2019). The findings indicate that, in the past 70 years, the MJE has evolved through seven stages of flushing and siltation under the condition of decreasing incoming sediment: "significant siltation - siltation - minor siltation - significant erosion - significant siltation - minor siltation - significant erosion". Despite decreased incoming material, the estuary underwent substantial siltation from 1998 to 2005. Extreme meteorological conditions were the cause of this anomaly. The "severe flushing" phenomenon occurred in the study area from 2011 to 2019, and the comparison of pre-dam and post-dam at the estuary revealed that extreme weather can only adjust in stages and cannot change the overall state of the estuary flushing due to the reduction of incoming sediment in the basin. According to the EOF (Empirical Orthogonal/Eigen Function) study of four sections of the estuary, it is most impacted by incoming sediment from the watershed, followed by severe weather conditions. Our research is crucial for comprehending how human behavior and harsh weather might affect the development of MJE, and it offers sound advice for the long-term management of MJE. [ABSTRACT FROM AUTHOR]

With global climate change and increasingly extreme weather conditions, the water quality of the Lijiang River Basin (LRB) is facing huge threats. At present, there is still a lack of systematic research on water quality indicators and the influence of indirect factors such as meteorological factors on it in the LRB. Therefore, this study is based on the meteorological, hydrological, and water quality data of the LRB from 2012 to 2018, using the Mann–Kendall test, Morlet wavelet method, Spearman's rank correlation coefficient, sensitivity, and contribution rate to quantitative analysis of the relationship between climate conditions and water quality indicators. The results show that the change trends of these hydrological and climatic conditions have almost no significant sudden change; precipitation and streamflow are decreasing each year; the streamflow trend exhibits time hysteresis; precipitation has a stronger influence downstream than on the local area; water quality indicators of both stations exhibited a change period of around 18 to 20 months, with the exception of pH. Water quality indicators are insensitive to precipitation and streamflow, and sensitive to humidity and wind speed; DO was negatively correlated with climate indicators apart from wind speed; almost all water quality indicators in Yangshuo are highly sensitive to air temperature, and the contribution rate of air temperature to ORP and TP reached 4.81% and 3.56%, respectively; sunshine duration has a positive impact on reducing NH4-N and TP. The difference between Yangshuo and Guilin is mostly due to the input of external sources on both sides of the Lijiang River, which results in variations in climate conditions sensitivities. [ABSTRACT FROM AUTHOR]

Pressure on river water resources may increase continuously under global climate change and the increasing intensity of human activity, and the identification of river water sources is needed to maintain water resource sustainability. In this study, river water sources were studied using hydrochemical tracers (i.e. the major ions) and end‐member mixing analysis (EMMA) during two hydrological years, in the subtropical monsoon basin of the Xiangjiang River in the south‐central China. Various water types including precipitation, river water, and mountain creek water, were collected in the basin at a high frequency. The results of EMMA showed that the average contributions from the direct input of precipitation, near‐surface runoff (represented by mountain creek water), and groundwater (represented by river water sampled during the base flow period) were 28 ± 24%, 49 ± 24% and 23 ± 16%, respectively. The contributions from these water sources to the river water varied greatly within the year, which may indicate a shift in the major flow pathways from direct precipitation input and near‐surface flow pathways in the spring rainy months (e.g. from March to May), to a deeper flow pathway in the dry or rainless months (e.g. January, February, July and December). The shift of the major flow pathways may be due to the factors such as the seasonality of precipitation, evapotranspiration and soil wetness conditions. Groundwater and near‐subsurface runoff dominated the river water and the direct input of precipitation was negligible during the dry or rainless months, and consequently, the river water chemistry was less diluted and more influenced by water‐soil/rock interactions and anthropogenic pollution during these months. The creek water contribution to the river water was relatively high in summer, especially in June and July 2021, which may indicate the substantial inter‐seasonal carryover of precipitation that contributed to the river water. With the projected increased frequency of extreme weather events such as seasonal drought, streamflow in the subtropical monsoon regions may experience greater recharge by deeper flow pathways, with the enhanced role of base flow in regulating streamflow, and there may be an increased risk to the water resource security under the condition of the decreased river dilution capacity and increased anthropogenic pollution. [ABSTRACT FROM AUTHOR]

Extreme precipitation events severely affect ecosystems and human society. While most existing studies investigated either their temporal changes or spatial extent, the joint behaviors in both time and space are neglected. Here, we examine different evolution patterns of spatiotemporally contiguous precipitation events (SCEPEs) across China during 1997–2021 from a three‐dimensional (3D, latitude × longitude × time) perspective. The SCEPEs exhibit distinct behaviors in different subregions. The SCEPEs in northwestern areas have relatively longer moving distances and weaker magnitude, mostly originating from the west and traveling to the east. Southeastern events display stronger magnitudes and travel at shorter distances, characterized by a more localized phenomenon. Since 1997, the frequency of SCEPEs in China has nearly doubled, their magnitude and affected areas have increased, but the moving distance and speed have decreased. Our findings provide important references for predicting extreme weather events and mitigating their detrimental impacts. Plain Language Summary: Extreme precipitation events have serious impacts on human society and ecosystems, but their evolution behaviors in both time and space dimensions are not understood. For the first time, here we study the "true" 3D (latitude × longitude × time) structures and evolution patterns of spatiotemporally contiguous extreme precipitation events (SCEPEs) across China that occur synchronously in neighboring regions or consecutively in adjacent days. The results show that SCEPEs in China exhibit distinct behaviors in different locations and time periods. Spatially, the SCEPEs in northern China move eastward at faster speeds and longer distances than southern ones, which tend to direct to all directions and show local features. Temporally, SCEPEs have been significantly intensified from 1997 to 2021, in terms of increased frequency, magnitude, and affected areas, and decreased moving distance and moving speed. Our findings from a 3D perspective offer new scientific references for forecasting and adapting precipitation extremes and their resultant devastating disasters. Key Points: The 3D evolution properties of spatiotemporally contiguous extreme precipitation events (SCEPEs) in China are examined for the first timeNorthern SCEPEs move eastward and faster at longer distance than southern ones, which tend to be from all directions and show local featuresThe moving distance and speed of SCEPEs have declined, but their frequency, magnitude, and area have increased since late 1990s [ABSTRACT FROM AUTHOR]

Understanding the evolution of heatwaves is important for their prediction, mitigation, and adaptation. While most studies focused on either their temporal variability at individual station (or grid point) or the spatial variation over fixed durations, their daily joint evolution over space and time remains largely unexplored. Here, we investigate multi‐dimensional characteristics of spatiotemporally contiguous heatwaves across China during 1961–2018 using observational data from a 3D perspective (i.e., latitude × longitude × time). Results obtained by the 3D identification show that large contiguous heatwaves in China exhibit distinct characteristics in different geographical locations and time periods. Heatwaves in northern areas prefer to move from west to east at a faster speed, persist longer, and have greater extent and intensity than southern heatwaves, which are generally originated from the east and move westward. It is also found that contiguous heatwaves are growing in frequency, magnitude, areal extent, duration, and traveling distance across China. Plain Language Summary: Known as episodes with temperature exceeding a certain threshold, heatwaves exert severe detrimental impacts on human health. Understanding their joint evolution at both temporal and spatial dimensions is beneficial for us to mitigate the adverse effects and adapt ourselves to future heatwave increases under global warming. However, previous studies mainly focused on either the temporal or spatial changes of heatwaves rather than their co‐variability over both time and space. Here we introduce a new method, the 3D connected component algorithm, to track the 3D evolution of spatiotemporally contiguous heatwaves over China during 1961–2018 using observational data. We find that contiguous heatwaves over northern China prefer to move eastward at a faster speed, persist longer, and have greater extent and intensity than southern heatwaves, which are generally originated from the east and move westward. Contiguous heatwaves show significant increases in frequency, magnitude, coverage, duration, and traveling distance. Key Points: True 3D structure and spatiotemporal evolution of large contiguous heatwave over China are tracked by the 3D connected component labeling algorithmContiguous heatwaves in China exhibit distinct characteristics and evolution patterns in different geographical locations and time periodsSubstantial increases are observed in the frequency, area, magnitude, duration, and moving distance of contiguous heatwaves since the 1960s [ABSTRACT FROM AUTHOR]

Historical records truthfully document human life and environment associated with climate changes. We quantify official historical records of China dating back last 2000 years to examine the disasters due to anomalous temperatures of cold or hot, irregular precipitations of wet or dry, and floods in inland/coastal or Northern/Southern areas in four seasons that possibly linked to solar activities during 1-1825 CE (Common Era). It is found that the proportion of disaster years is positively associated with the time periods, and therefore, both the cases with high and low solar activity (HSA and LSA) leading are under study. Statistical results show that extreme cold weather occurs particularly in the Winter and Spring during LSA periods. Irregularities precipitations, including heavy rain/hail/snow and severe drought are significantly frequent during LSA periods, while floods on inland and coastal river basins tend to occur more frequently in LSA and HSA periods, respectively. The disasters owing to irregularities precipitations and floods frequently happen in Summer and Autumn, which suggests that the irregular precipitations could cause the floods. All the disasters occur significantly in the Northern China, which suggests the climate boundary of the Qinling–Huaihe Line along at about 33°N being essential. In total, all the disasters due to the anomalously cold temperatures, irregular precipitations, and floods tend to occur during the LSA periods. [ABSTRACT FROM AUTHOR]

Drought severity was simulated with four drought indices to examine the impacts of climate change on drought conditions in Shaanxi province over the period 1951 to 2012. The drought metrics analyzed were based on the original Palmer drought severity index (orPDSI), self-calibrated PDSI (scPDSI), the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI). Both Thornthwaite (Thor) and Penman-Monteith (PM) parameterizations were used to calculate potential evapotranspiration (PET), and the differences between two PET estimators were studied. Nonparametric Mann-Kendall monotonic test was used to examine the trends of hydroclimatic data. Series of drought indices were compared at five meteorological stations with different climate characteristics, located in the north, central and south parts of Shaanxi province, respectively. Effects of climate change in drought conditions were investigated with hypothetical progressive precipitation decrease (−15 %) and temperature increase (2 °C). The results showed that there was discrepancy between PET estimated using the Thor and PM parameterization estimators, while the SPEI calculated with the two PET estimators are found to be similar. The SPEI has the combined advantages over the scPDSI and the SPI, considering the effect of temperature variability on drought severity and its multi-scalar characteristic, while scPDSI has an inherent approximately 12-month time scale. The Pearson's correlation is used to compare the three pairs of drought indices combinations at different time scales. Under climate change conditions, the drought severity increases with the decline of precipitation and higher water demand as a result of the temperature increase based on the metrics of the scPDSI, the SPI and the SPEI. [ABSTRACT FROM AUTHOR]