通讯机构：
[Feng, C ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
river network system evolution;adaptation;urbanization;GTWR model;Xiangjiang River Basin
摘要：
The research focuses on the difficult problem of quantifying the adaptation state of river network system development under rapid urbanization. Based on the river network system data and remote sensing image data of the past 30 years, this study discusses the evolution of the river network system and its adaptability. The geographically and temporally weighted regression (GTWR) model was used to reveal the response of the river network system in the Xiangjiang River Basin to urbanization. The results suggest that the Xiangjiang River Basin has experienced a significant increase in urban land due to the strong disturbance by human activities in the last 25 years. The number indicators of river network system such as overall water surface rate and river network density have decreased by 10.04% and 13.99%, respectively. Drainage structure indicators such as tributary development coefficient and structural stability decreased by 6.89% and 4.40%, respectively. The influence of three-dimensional urbanization on the intensity of river network density change is spatiotemporal heterogeneity during 1995-2020. It shows that population factors have a significant negative impact on the upstream area. The regression coefficient between river network density and per capita GDP in the basin is positive. The regression coefficient of urban land is negative, indicating that urban expansion has a significant negative effect on river network density in Xiangjiang River basin. The analysis of the relationship between urbanization and river network system evolution by using the coordination degree model shows that: in the early stage, the level of urbanization is low, the adjustment capacity and carrying capacity of river network are strong, and the coordination degree of urbanization and river network system is small. The level of urbanization has reached a new height, especially in the upstream central cities such as Chang-Zhu-Tan from 2015 to 2020. At this time, the increase of coordination degree is characterized by the mutual promotion of urbanization and river network development, and the improvement of their adaptive development requirements. This study quantitatively reveals the changing characteristics and influencing factors of the adaptability of river network systems and urban spatial development, which can provide scientific support for regional human-water harmony, flood prevention and mitigation, and green urbanization development.
通讯机构：
[Bo Zhang] S;Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China<&wdkj&>Guangdong Provincial Center for Urban and Migration Studies, Guangzhou 510006, China<&wdkj&>School of Geography and Remote Sensing, Guangzhou University, Guangzhou 510006, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
population aging;green total factor productivity;spatiotemporal analysis;spatial clustering;spatial spillover effect;spatial Durbin model
摘要：
China is a rapidly aging nation. Therefore, it is a matter of urgency to address the challenges of aging in China and to coordinate the relationships between population aging, environmental issues, and socio-economic development. However, few empirical studies have thus far analyzed the impact of aging on green total factor productivity (GTFP) in China. Hence, this study employs a global Malmquist–Luenberger index method (GMLI) to calculate the GTFP scores of 30 Chinese provinces from 2002 to 2018. We apply spatiotemporal analysis methods to identify the variations of population aging and GTFP scores and then build a spatial econometric model to examine the impact of population aging on GTFP. Our study findings are as follows. (1) Whereas at the beginning of the 21st century, provinces with deep aging were mostly situated in the east, the population aging issue in China is now spreading across the entire country. (2) From a dynamic perspective, the overall GTFP growth rate in China during the sample period depicts a U-shaped structure with time. (3) Results of the spatial Durbin model show that the impact of population aging in a given region on GTFP is negative, but the spatial spillover effect of aging in neighboring regions on GTFP in a given region is positive, resulting in the loss of younger local labor forces in some provinces due to low birth rates and migration to neighboring regions. Finally, to cope with a growing aging population and to possibly eliminate the negative impacts of population aging on high-quality sustainable development, the government should promote the establishment of the old-age security system; increased investment in R & D and wide use of advanced technology should also be urgently encouraged.
作者机构：
[Wu, Jing; Yang, Xia; Peng, Bo; Peng, B; Wu, Sicheng; Chen, Haisheng; Guo, Xintong; Xie, Shurong; Fang, Xiaohong; Dai, Yanan] Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.;[Wu, Jing; Yang, Xia; Peng, Bo; Peng, B; Wu, Sicheng; Chen, Haisheng; Guo, Xintong; Dai, Yanan] Hunan Normal Univ, Key Lab Environm Heavy Met Contaminat & Ecol Remed, Changsha 410081, Peoples R China.;[Fang, Xiaohong] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Xie, Shurong] East China Univ Technol, Sch Earth Sci, Nanchang 330013, Peoples R China.
通讯机构：
[Peng, B ] H;Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.;Hunan Normal Univ, Key Lab Environm Heavy Met Contaminat & Ecol Remed, Changsha 410081, Peoples R China.
作者机构：
[Gao, Chanchan] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421000, Peoples R China.;[Gao, Chanchan; Liu, Min] East China Normal Univ, Sch Ecol & Environm Sci, Shanghai Key Lab Urban Ecol Proc & Ecorestorat, Shanghai 200241, Peoples R China.;[Fang, Dekun; Zhang, Fengying] China Natl Environm Monitoring Ctr, Beijing 100012, Peoples R China.;[Wang, Qingtao] Hebei Univ Engn, Sch Landscape & Ecol Engn, Handan 056038, Hebei, Peoples R China.;[Liu, Min] China Acad Forens Sci, Key Lab Forens Sci, Minist Justice, Shanghai 200063, Peoples R China.
通讯机构：
[Min Liu] K;Key Lab of Forensic Science, Ministry of Justice, China (Academy of Forensic Science), Shanghai 200063, China<&wdkj&>Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
关键词：
Air pollution controls;Air quality;COVID-19;China;Harmonic model
摘要：
Air pollution is a threat to public health in China, and several actions and plans have been implemented by Chinese authorities in recent years to mitigate it. This study examined the spatial distribution of changes in urban air pollutants (UAP) in 336 Chinese cities from 2016 to 2020 and their responses to air pollution controls and the COVID-19 pandemic. Based on the harmonic model, decreases in fine particles (PM(2.5)), inhalable particles (PM(10)), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), and carbon monoxide (CO) levels were found in 90.7%, 91.9%, 75.2%, 94.3%, and 88.7% of cities, respectively, while an increase in ozone (O(3)) was found in 87.2% of cities. Notable spatial heterogeneity was observed in the air pollution trends. The greatest improvement in air quality occurred mainly in areas with poor air quality, such as Hebei Province and its surrounding cities. However, some areas (i.e., Yunnan and Hainan provinces) with good air quality showed a worsening trend. During the 13th Five-Year Plan period (2016-2020), the remarkable effects of PM(2.5) and SO(2) pollution control plans were confirmed. Additionally, economic growth in 74.2% of the Chinese provinces decoupled from air quality after implementing pollution control measures. In 2020, several Chinese cities were locked down to reduce the spread of COVID-19. Except for SO(2), the national air pollution in 2020 improved to a greater extent than that in 2016-2019; In particularly, the contribution of simulated COVID-19 to NO(2) reduction was 66.7%. Overall, air pollution control actions improved urban PM(2.5), PM(10), SO(2), and CO, whereas NO(2) was reduced primarily because of the COVID-19 pandemic.
期刊：
Global Ecology and Conservation,2023年46:e02617 ISSN：2351-9894
通讯作者：
Liu, N
作者机构：
[Deng, Yunyuan; Jiang, Wulin; Zou, Jun] Hengyang Normal Univ, Hunan Natl Local Joint Engn Lab Digital Preservat, Hengyang 421002, Peoples R China.;[Jiang, Wulin] Hengyang Normal Univ, Cooperat Innovat Ctr Digitalizat Cultural Heritage, Hengyang 421002, Peoples R China.;[Wang, Chunmei; Liu, Na; Liu, N; Deng, Yunyuan; Jiang, Wulin; Zou, Jun] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Jiang, Wulin] Int Ctr Space Technol Nat & Cultural Heritage HIST, Hengyang Base, Hengyang 421002, Peoples R China.;[Wang, Chunmei] Chongqing Normal Univ, Sch Geog & Tourism, Chongqing 401331, Peoples R China.
通讯机构：
[Liu, N ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
Ecological quality;RSEI-2;Net primary productivity;Xiangxi UNESCO Global Geopark
摘要：
Geoparks are home to unique and precious geological sites and have a rich historical and cultural heritage. Most studies have focused on their tourism value and/or educational significance. However, far too little attention has been paid to the impact of geopark construction on the local ecological environment. The Xiangxi UNESCO Global Geopark (XXGG) was used as a case study to explore the impact of global geopark construction on local ecological quality. Three ecological indices, including an ecological quality index based on productive, residential, and ecological land use, an improved remote-sensing ecological index (RSEI-2), and net primary productivity (NPP), were adopted to evaluate the ecological quality of XXGG during two periods: before construction (from 2015 to 2017) and during construction of XXGG (from 2018 to 2020). The results show that: (1) in general, all ecological quality indicators showed a downtrend (from 2015 to 2017) followed by an uptrend (from 2018 to 2020), indicating that construction and development of XXGG has had a significant positive effect on local ecological quality. This occurred because a series of environmental protection measures were taken after application to the United Nations Educational, Scientific, and Cultural Organization (UNESCO) Global Geoparks (UGGPs) for membership at the end of 2017. (2) The areas of XXGG with excellent and improved ecological quality are mainly distributed in the northern and southeastern portions, which are located in the protected area with high coverage rates of forest and other vegetation. Poor ecological quality in the east and south is closely related with human activities, such as ethnic tourism development. The results explore the relationship between regional construction of the geopark and ecological effects and provide a scientific reference for sustainable development of global geoparks.
