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Vegetation phenology and its spatiotemporal driving factors are essential to reflect global climate change, the surface carbon cycle and regional ecology, and further quantitative studies on spatiotemporal heterogeneity and its two-way driving are needed. Based on MODIS phenology, meteorology, land cover and other data from 2001 to 2019, this paper analyzes the phenology change characteristics of the Yangtze River Delta from three dimensions: time, plane space and elevation. Then, the spatiotemporal heterogeneity of phenology and its driving factors are explored with random forest and geographic detector methods. The results show that (1) the advance of start of season (SOS) is insignificant—with 0.17 days per year; the end of season (EOS) shows a significant delay—0.48 days per year. The preseason temperature has a greater contribution to SOS, while preseason precipitation is main factor in determining EOS. (2) Spatial differences of the phenological index do not strictly obey the change rules of latitude at a provincial scale. The SOS of Jiangsu and Anhui is earlier than that of Zhejiang and Shanghai, and EOS shows an obvious double-clustering phenomenon. In addition, a divergent response of EOS with elevation grades is found; the most significant changes are observed at grades below 100 m. (3) Land cover (LC) type is a major factor of the spatial heterogeneity of phenology, and its change may also be one of the insignificant factors driving the interannual change of phenology. Furthermore, nighttime land surface temperature (NLST) has a relatively larger contribution to the spatial heterogeneity in non-core urban areas, but population density (PD) contributes little. These findings could provide a new perspective on phenology and its complex interactions between natural or anthropogenic factors. [ABSTRACT FROM AUTHOR]

Amphibians and reptiles, especially the critically endangered Chinese alligators, are vulnerable to climate change. Historically, the decline in suitable habitats and fragmentation has restricted the distribution of Chinese alligators to a small area in southeast Anhui Province in China. However, the effects of climate change on range‐restricted Chinese alligator habitats are largely unknown. We aimed to predict current and future (2050s and 2070s) Chinese alligator distribution and identify priority conservation areas under climate change. We employed species distribution models, barycenter migration analyses, and the Marxian model to assess current and future Chinese alligator distribution and identify priority conservation areas under climate change. The results showed that the lowest temperature and rainfall seasonality in the coldest month were the two most important factors affecting the distribution of Chinese alligators. Future predictions indicate a reduction (3.39%–98.41%) in suitable habitats and a westward shift in their distribution. Further, the study emphasizes that suitable habitats for Chinese alligators are threatened by climate change. Despite the impact of the Anhui Chinese Alligator National Nature Reserve, protection gaps persist, with 78.27% of the area lacking priority protected area. Our study provides crucial data for Chinese alligator adaptation to climate change and underscores the need for improved conservation strategies. Future research should refine conservation efforts, consider individual plasticity, and address identified limitations to enhance the resilience of Chinese alligator populations in the face of ongoing climate change. [ABSTRACT FROM AUTHOR]

In order to explore the evolvement mechanism of hydrological elements under climate change and the interaction impacts, the hydro-meteorological elements, like temperature, precipitation, runoff, and evaporation, are studied by statistical analysis method and cause analysis approach in this paper. Initially, in terms of climate change across Anhui province, the average temperature data from 1960 to 2009 at 15 meteorological stations are selected from China Meteorological Data Sharing Network to analyze the spatio-temporal variation of temperature characteristics. Secondly, from the perspective of Xin'anjiang Basin, evolution rules of hydro-meteorological elements are studied through deviation variation of every 10 years and the long-term development trend from 1981 to 2010 at 9 hydrological stations. And the influence of climate change on runoff is analyzed according to the principle of runoff formation, and the response of runoff to precipitation and temperature is predicted with the simulating future climate change by climate models. The results show that, through statistics, the average temperature in Anhui province is in a fluctuating downward state from 1960 to 1990. After 1990, the uptrend is significant. In Xin'anjiang Basin, the annual precipitation declines overally, especially at some stations it is obvious. The variation of runoff is in a downtrend consistent with precipitation, but it is not noticeable, taken as a whole. The average evaporation changes unremarkably, except in summer and winter. Under three scenarios of A1B, A2 and B1, it is assumed that temperature, precipitation and runoff are all increasing in the future. Through cause analysis, these mainly seem to be affected by the circulation of weather background and sea surface temperature. Based on the analysis of hydro-meteorological elements under climate change and the forecasting of their future changes, the development of regional water resources can be grasped which is of great significance for human interests to water supply scheme, water conservancy project planning, and the economic-social sustainablility. [ABSTRACT FROM AUTHOR]

With global climate change and rapid urbanization, it is critical to assess urban flood resilience (UFR) within the social-economic-natural complex ecosystem in dealing with urban flood disasters. This research proposes a conceptual framework based on the PSR-SENCE model for evaluating and exploring trends in urban flood resilience over time, using 27 cities in the Yangtze River Delta (YRD) of China as case studies. For the overall evaluation, a hybrid weighting method, VIKOR, and sensitivity analysis were used. During that time, UFR in the YRD region averaged a moderate level with an upward trend. This distinguishes between the resilience levels and fluctuation trends of provinces and cities. Jiangsu, Zhejiang, and Anhui provinces all displayed a trend of progressive development; however, Shanghai displayed a completely opposite pattern, mainly because of resilience in the state dimension. During that time, 81.41% of cities exhibited varying, upward trends in urban flood resistance, with few demonstrating inverse changes. Regional, provincial, and city-level implications are proposed for future UFR enhancement. The research contributes to a better understanding of the urban complex ecosystem under flood conditions and provides significant insights for policymakers, urban planners, and practitioners in the YRD region and other similar flood-prone urban areas. [ABSTRACT FROM AUTHOR]

• A dynamic two-stage SBM model with non-discretionary variables is proposed. • China's CPLR efficiency under four scenarios of extreme temperatures is measured. • The influences of extreme temperatures on the CPLR efficiency are highlighted. • A comparative analysis of CPLR efficiency under four scenarios is provided. With the influence of climate changes resulting in more extremely days, we might expect to face a rise in associated coal productivity losses and land destruction. Numerous studies have focused on measuring the efficiency of coal production system. Yet scant studies have considered their internal structure, reconstructed lands, and especially the impact of extreme temperatures. Then, this paper divided such a system into stages of coal production (CP) and land reconstruction (LR), named the CPLR system. This study proposes a modified two-stage dynamic slacks-based measure model with non-discretionary variables for measuring the CPLR efficiency under four scenarios of extreme temperatures. The results are as follows. (1) The CPLR system for 24 provinces under four scenarios spanning 2012 to 2017 had relatively low efficiency except for Fujian, Inner Mongolia and Sichuan, which is mainly caused by the bad performance of the LR system. (2) Extreme temperatures must be considered in measuring CPLR efficiency and its stage efficiency, or otherwise the underestimation of CPLR efficiency and CP efficiency will become in 18 provinces. The negative impacts of extreme temperatures on the efficiency of reconstructed lands and raw coal production should be noticed, especially for Anhui. [ABSTRACT FROM AUTHOR]

By analyzing the effects of environmental variables on plants, changes in plant distribution as a result of climate oscillations can be studied, which is of great significance to plant protection and management policies. Acer cordatum Pax (Aceraceae) is a non-deciduous tree distributed in valleys and streams in eastern China. Due to the effects of changing climate (warmer, drier conditions) and human impacts, the number of wild individuals of A. cordatum has exhibited a decrease trend, which is in urgent need of protection. In this study, the maximum entropy algorithm (MaxEnt) was used to predict the potential geographical distribution of A. cordatum during the Last Interglacial (LIG), and Last Glacial Maximum (LGM), current, 2060s, and 2080s periods. The model used geographic location information of 337 A. cordatum and six climatic variables. The area under the receiver operating characteristic curves (AUC) of the simulation results were more than 0.95, indicating high accuracy in the simulation result. The mean temperature of coldest quarter, precipitation of warmest quarter, precipitation of driest month, and precipitation of seasonality were important climatic variables influencing the geographic distribution of A. cordatum. Based on the simulate results, the potential distribution areas of A. cordatum experienced a process of expansion and then contraction from LIG to the future. In the future, some potential suitable areas provinces will likely shrink (Guizhou, Fujian, and Anhui), even almost disappear (Chongqing), and the general distribution will trend to transfer in a northeastward direction. It is hoped that this study can provide a theoretical reference for the future protection of A. cordatum. [ABSTRACT FROM AUTHOR]

Reference evapotranspiration (ET0) is essential for agricultural production and crop water management. The recent climate change affecting the spatiotemporal variation of ET0 in eastern China continues to still be less understood. For this purpose, the latest observed data from 77 meteorological stations in Anhui province were utilized to determine the spatiotemporal variations of ET0 by the use of the Penman–Monteith FAO 56 (PMF-56) model. Furthermore, the Theil–Sen estimator and the Mann–Kendall (M–K) test were adopted to analyze the trends of ET0 and meteorological factors. Moreover, the differential method was employed to explore the sensitivity of ET0 to meteorological factors and the contributions of meteorological factors to ET0 trends. Results show that the ET0 decreased significantly before 1990, and then increased slowly. The ET0 is commonly higher in the north and lower in the south. ET0 is most sensitive to relative humidity (RH), except in summer. However, in summer, net radiation (Rn) is the most sensitive factor. During 1961–1990, Rn was the leading factor annually, during the growing season and summer, while wind speed (u2) played a leading role in others. All meteorological factors provide negative contributions to ET0 trends, which ultimately lead to decreasing ET0 trends. During 1991–2019, the leading factor of ET0 trends changed to the mean temperature (Ta) annually, during the growing season, spring and summer, and then to Rn in others. Overall, the negative contributions from u2 and Rn cannot offset the positive contributions from Ta and RH, which ultimately lead to slow upward ET0 trends. The dramatic drop in the amount of u2 that contributes to the changes in ET0 in Region III is also worth noting. [ABSTRACT FROM AUTHOR]

With the changing global climate, the occurrence of drought has become more frequent and serious in Anhui Province, an important agricultural production area. It is necessary to investigate and detect characteristics of the frequent droughts, which can provide reasonable suggestions to reduce their adverse influences. In this study, temporal variability characteristics of the Standardized Precipitation Index (SPI) with different time scales were analyzed based on the daily precipitation data of 16 stations during 1961–2010. Drought characteristics, including duration and severity, were then defined using run theory based on SPI with a 3-month time scale. The most suitable distribution function was selected to define the univariate marginal distributions of drought duration and severity. Finally, the bivariate joint probability distributions for different drought partitions were assessed based on the copula function, and spatial distributions of their return periods developed. Results indicate the following: (1) the duration and severity of droughts in Anhui Province have been decreasing and the spatial distribution of return periods for drought duration and severity are similar. Average drought duration was between 3.29 and 3.69 months, increasing gradually from north to south, and average drought severity was between 2.11 and 3.54, increasing from northeast to southwest. (2) When mild droughts happen, the drought bivariate return periods were 3.78–6.56 years. The highest values of moderate, severe, and extreme droughts occurred in northern and southwestern areas of Anhui Province, and the lowest values occurred in the north-central and south-eastern areas. [ABSTRACT FROM AUTHOR]