population change

人口变化
  • 文章类型: Journal Article
    城市萎缩引发的公共资源公平性是一个全球性挑战。重要的是,城市萎缩对卫生服务资源配置的影响需要更好地理解。本研究探讨了人口变化对收缩城市的政府投资和卫生服务提供的影响。
    使用中国城市统计年鉴(2010-2020)的数据,我们采用回归不连续(RD)和固定效应模型来检验城市萎缩与卫生服务提供之间的因果关系.
    缩小的城市在卫生资源方面显示出巨大的差异,特别是床数(-1,167.58,p<0.05)和医生可用性(-538.54,p<0.05)。经济发展(p<0.01)和财政自主权(p<0.01)影响医院病床分布。对公共服务的投资(小学和教师,p<0.01)影响卫生资源提供。稳健性测试支持我们的结果。
    这项研究揭示了城市萎缩如何扰乱医疗服务的提供和公平,建立城市收缩/扩张与卫生资源配置之间的因果关系,强调城市人口变化造成的不平衡。城市扩张加剧了对卫生资源的争夺,而不断缩小的城市由于政府的不情愿而难以提供足够的资源。政策制定者应调整卫生资源分配策略,以满足不断变化的城市景观中的患者需求。
    UNASSIGNED: The equity of public resources triggered by city shrinkage is a global challenge. Significantly, the impact of city shrinkage on the allocation of health service resources needs to be better understood. This study explores the impact of population change on government investment and health service delivery in shrinking cities.
    UNASSIGNED: Using data from China\'s Urban Statistical Yearbook (2010-2020), we employ regression discontinuity (RD) and fixed-effect models to examine the causal relationship between city shrinkage and health service provision.
    UNASSIGNED: Shrinking cities show significant disparities in health resources, particularly in bed numbers (-1,167.58, p < 0.05) and doctor availability (-538.54, p < 0.05). Economic development (p < 0.01) and financial autonomy (p < 0.01) influence hospital bed distribution. Investments in public services (primary schools and teachers, p < 0.01) affect health resource delivery. Robustness tests support our results.
    UNASSIGNED: This study reveals how city shrinkage disrupts health service provision and equity, establishing a causal relationship between city shrinkage/expansion and health resource allocation, emphasizing the imbalance caused by urban population changes. City expansion intensifies competition for health resources, while shrinking cities struggle to provide adequate resources due to government reluctance. Policymakers should adapt health resource allocation strategies to meet patient demands in changing urban landscapes.
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  • 文章类型: Journal Article
    虽然喀斯特荒漠化治理地区的生态服务得到了改善,目前尚不清楚人口减少如何通过生态资产影响生态系统服务供给能力。在这项研究中,泰尔-森中位数,回归分析,和方差划分被应用于探索人口变化的联系(观察到的数据和共享的社会经济途径1-代表性的集中途径2.6),生态资产构成(土地利用),质量(归一化植被指数[NDVI]和树高),和生态系统服务在不同时期(人口增长和衰退期)。结果表明,生长期(2000-2038)的种群变化以迁移模式为主。在以人口向外迁移为主的退化生态区(喀斯特荒漠化)中,2000-2020年,森林净扩张15.88%,NDVI和树高分别增长0.57%和54.96%,生态系统服务供给能力提高2.68%。相比之下,在人口迁移的非退化生态区(非喀斯特和喀斯特非荒漠化)中,森林变化率(-5.40%和-23.68%),NDVI(0.49%和0.53%),树高(-8.35%和-31.25%),生态系统服务供给能力(2.04%和2.18%)明显低于退化生态区。在人口下降期间(2039-2100),尽管在生长期两个地区之间的迁移模式被单个地区内的人口下降所取代,人口减少与生态资产和服务供给能力之间仍然存在正相关关系。总的来说,研究发现,涉及向外迁移和下降的人口减少两种方式都可以减轻退化生态区的土地压力,通过调节生态资产来增强生态系统服务供给能力。
    Although ecological services have been improved in karst desertification control areas, it is still unclear how population shrinkage affects ecosystem service supply capability through ecological assets. In this study, Theil-Sen median, regression analysis, and variance partitioning were applied to explore the linkages of population change (observed data and shared socioeconomic pathways 1-representative concentration pathways 2.6), ecological asset composition (land use), quality (Normalized difference vegetation index [NDVI] and tree height), and ecosystem services in different periods (population growth and decline periods). The results showed that the population change during the growth period (2000-2038) was dominated by migration patterns. In degraded ecoregions (karst desertification) dominated by population out-migration, the net expansion of forest was 15.88 % during 2000-2020, NDVI and tree height increased by 0.57 % and 54.96 %, and ecosystem service supply capability increased by 2.68 %. In contrast, in non-degraded ecoregions (non-karst and karst non-desertification) with population in-migration, change rates of forest (-5.40 % and - 23.68 %), NDVI (0.49 % and 0.53 %), tree height (-8.35 % and - 31.25 %), and ecosystem service supply capability (2.04 % and 2.18 %) were apparently lower than degraded ecoregions. During the population decline period (2039-2100), although the migration pattern between two regions during the growth period was replaced by a population drop within a single region, the positive correlation between population shrinkage with ecological assets and service supply capability was still followed. Overall, the study found that both ways of population shrinkage that involve out-migration and decline can alleviate the land pressure of degraded ecoregions, which enhances ecosystem service supply capability by regulating ecological assets.
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  • 文章类型: Journal Article
    农业占中国淡水消费量的61%。尽管人口和饮食对用水量有重大影响,对其影响的原因和程度知之甚少。通过应用环境扩展的多区域投入产出模型,在5种情景中估算了中国31个省20个农业部门的蓝色和绿色水足迹的变化。水足迹网络紧密相连,超过50%的省份是蓝水足迹的净进口国,发达省份蓝色和绿色水足迹进口总量的70%,发展中省份蓝色和绿色水足迹出口总量的65%,由经济发达省份驱动和主导的流量分布。研究结果还强调,人口变化对水足迹的影响微不足道,分别为2030年和2050年减少水足迹贡献0.51%和5.78%。种群和膳食结构的同时变化对水足迹的影响高于种群变化,低于膳食结构变化。水足迹变化的主要驱动力是饮食结构的变化,这对水足迹产生了双重影响。首先,它使蓝色和绿色的水足迹分别增加了33%和12%,分别,从而加剧了对生产侧水资源的强制性影响。第二,它导致了从谷物到水果的蓝色和绿色水足迹的主要贡献部门的变化,蔬菜,还有土豆.因此,当人口改变和优化其饮食结构时,必须更加关注水资源的威胁和压力。这将导致更好的科学管理和更有效地利用水资源。
    Agriculture accounts for 61 % of fresh water consumption in China. Although population and diet have a significant impact on water consumption, little is known about the reasons for and extent of their influence. Changes in the blue and green water footprint of 20 agricultural sectors in 31 Chinese provinces were estimated in 5 scenarios by applying the environmentally expanded multi-regional input-output model. The water footprint network is strongly interconnected, with over 50 % of the provinces characterized as net importers of the blue water footprint, 70 % of the total blue and green water footprint imports in developed provinces, and 65 % of the total blue and green water footprint exports in developing provinces, with the flow distribution driven and dominated by economically developed provinces. The findings also highlighted that the impact of population change on the water footprint is insignificant, contributing 0.51 % and 5.78 % to the reduction of the water footprint in 2030 and 2050, respectively. The impact of simultaneous changes in the population and dietary structure on the water footprint was higher than population changes and lower than dietary structure changes. The main force driving changes in the water footprint was changes in the dietary structure, which resulted in a two-fold effect on the water footprint. First, it has increased the blue and green water footprint by 33 % and 12 %, respectively, thus aggravating the coercive impact on water resources on the production side. Second, it has led to a change in the main contributing sectors for the blue and green water footprint from cereals to fruits, vegetables, and potatoes. Therefore, when the population is changing and optimizing its dietary structures, a greater focus must be placed on threats and pressures to water resources. This will result in better scientific management and more efficient use of water resources.
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  • 文章类型: Journal Article
    背景:细颗粒物(PM2.5)对急性心肌梗死(AMI)的影响已得到广泛认可。然而,没有研究全面评估不同气候缓解和人口变化情景下未来PM2.5导致的AMI负担.我们旨在量化PM2.5-AMI关联,并估计山东省2030年和2060年六种综合情景下PM2.5导致AMI事件病例的未来变化。中国。
    方法:收集2017-2019年山东省136个区县每日AMI事件病例和大气污染物数据。使用分布滞后非线性模型进行了两阶段分析,以量化基线PM2.5-AMI关联。通过将拟合的PM2.5-AMI关联与六种综合情景下的预计每日PM2.5浓度相结合,估计了PM2.5引起的AMI事件病例的未来变化。我们使用分解方法进一步分析了驱动PM2.5相关AMI发病率变化的因素。
    结果:在lag05时,PM2.5暴露量每增加10μg/m3,与1.3%的超额风险相关(95%置信区间:0.9%,1.7%)为2017-2019年山东省AMI发病率。在2030年和2060年的情况1-3下,估计PM2.5导致的AMI事件总数将增加10.9-125.9%和6.4-244.6%,而在2030年和2060年的情况5-6下,它们将分别减少0.9-5.2%和33.0-46.2%。此外,由PM2.5引起的女性病例(2030年:-0.3%至135.1%;2060年:-33.2%至321.5%)和老龄化病例(2030年:15.2-171.8%;2060年:-21.5%至394.2%)的百分比增长将完全超过男性病例(2030年:-1.8%至133.2%;2060年:-41.1%至264.3%)和非老龄化病例(2030年:4在2030年和2060年的情况1-3下,人口老龄化是PM2.5相关AMI发病率增加的主要驱动因素,而空气质量的改善可以抵消碳中和和1.5°C目标实施下人口老龄化的负面影响。
    结论:雄心勃勃的气候政策(即,1.5°C的变暖限制和碳中和目标)以及严格的清洁空气政策对于减少山东省空气污染对健康的影响是必要的,中国,无论人口老龄化。
    BACKGROUND: The effects of fine particulate matter (PM2.5) on acute myocardial infarction (AMI) have been widely recognized. However, no studies have comprehensively evaluated future PM2.5-attributed AMI burdens under different climate mitigation and population change scenarios. We aimed to quantify the PM2.5-AMI association and estimate the future change in PM2.5-attributed AMI incident cases under six integrated scenarios in 2030 and 2060 in Shandong Province, China.
    METHODS: Daily AMI incident cases and air pollutant data were collected from 136 districts/counties in Shandong Province from 2017 - 2019. A two-stage analysis with a distributed lag nonlinear model was conducted to quantify the baseline PM2.5-AMI association. The future change in PM2.5-attributed AMI incident cases was estimated by combining the fitted PM2.5-AMI association with the projected daily PM2.5 concentrations under six integrated scenarios. We further analyzed the factors driving changes in PM2.5-related AMI incidence using a decomposition method.
    RESULTS: Each 10 μg/m3 increase in PM2.5 exposure at lag05 was related to an excess risk of 1.3 % (95 % confidence intervals: 0.9 %, 1.7 %) for AMI incidence from 2017 - 2019 in Shandong Province. The estimated total PM2.5-attributed AMI incident cases would increase by 10.9-125.9 % and 6.4-244.6 % under Scenarios 1 - 3 in 2030 and 2060, whereas they would decrease by 0.9-5.2 % and 33.0-46.2 % under Scenarios 5 - 6 in 2030 and 2060, respectively. Furthermore, the percentage increases in PM2.5-attributed female cases (2030: -0.3 % to 135.1 %; 2060: -33.2 % to 321.5 %) and aging cases (2030: 15.2-171.8 %; 2060: -21.5 % to 394.2 %) would wholly exceed those in male cases (2030: -1.8 % to 133.2 %; 2060: -41.1 % to 264.3 %) and non-aging cases (2030: -41.0 % to 45.7 %; 2060: -89.5 % to -17.0 %) under six scenarios in 2030 and 2060. Population aging is the main driver of increased PM2.5-related AMI incidence under Scenarios 1 - 3 in 2030 and 2060, while improved air quality can offset these negative effects of population aging under the implementation of the carbon neutrality and 1.5 °C targets.
    CONCLUSIONS: The combination of ambitious climate policies (i.e., 1.5 °C warming limits and carbon neutrality targets) with stringent clean air policies is necessary to reduce the health impacts of air pollution in Shandong Province, China, regardless of population aging.
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  • 文章类型: Journal Article
    在中国现代化的进程中,促进资源型城市的可持续发展是一个重大的战略问题,现在也成为一个世界性的问题。利用耦合模型验证了2009-2017年中国土地利用净碳通量与经济增长和人口变化的耦合关系。研究首次得出三者之间的耦合度越来越低的结论,相关性逐渐减弱,独立关系越来越突出。利用Tapio解耦模型,得出经济增长率高于土地利用净碳通量增长率的弱脱钩结论,而扩张的负脱钩是人口增长率低于净土地利用碳通量增长率的地方。
    In the process of China\'s modernization, promoting the sustainable development of resource-based cities is a major strategic issue and it has now also become a worldwide issue. This study uses the coupling model to validate the coupling relationship between China\'s land-use net carbon flux and economic growth and population change during 2009-2017. The study for the first time draws the conclusion that the coupling degree among the three is getting lower, the correlation is gradually weaker, and the independent relationship is becoming more and more prominent. Utilizing the Tapio decoupling model, we obtained the weak decoupling conclusion that the economic growth rate is higher than the growth rate of the land-use net carbon flux, while negative decoupling of sprawl is where the rate of population growth is less than the rate of net land-use carbon flux growth.
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  • 文章类型: Journal Article
    将人口暴露的变化归因于全球复合极端高温,结合了白天和晚上的极端炎热和更严重的影响,对于适应气候变化至关重要。根据耦合模型比对项目第六阶段(CMIP6)的日温度数据和人口数据,在全球和大陆尺度的排放和社会经济发展三种情景下,我们估计了两个未来时期人口暴露的变化,并评估气候和人口变化的贡献。我们发现,在不同的时期和场景下,暴露于复合热极端的空间模式是相似的,高暴露地区主要位于东亚,南亚,欧洲,以及美国东部和非洲的部分地区。在全球大多数地区,暴露量从基线(1980-2014)到21世纪中期和后期(2021-2055和2056-2090)有所增加。在一切照旧的情况下(SSP2-4.5),在21世纪后期,全球暴露量增加了约19倍,非洲的增幅最大,而欧洲的增幅最小。早期(SSP1-2.6)和无(SSP5-8.5)的缓解行动将减轻和加重增长率,分别。对于全球约78%-87%的陆地面积,暴露的变化主要是由气候变化引起的(占>69%),其次是气候和人口协同变化的相互作用效应(约占29%)。在中高纬度地区的部分地区,由于气候变化和人口变化的相反影响,暴露量小于预期。
    Attributing the changes in the population exposure to global compound hot extremes, which combine daytime-nighttime hot extremes with more severe impacts, is essential for climate change adaptation. Based on daily temperature data from the Coupled Model Intercomparison Project phase 6 (CMIP6) and population data, we estimate the changes in population exposure for two future periods under three scenarios of emission and socio-economic development at global and continental scales, and assess the contributions from climate and population changes. We find that the spatial patterns of exposure to compound hot extremes are similar for different periods and scenarios, and regions with high exposure are mainly located over East Asia, South Asia, Europe, and parts of eastern USA and Africa. The exposure shows an increase from baseline (1980-2014) to mid- and late 21st century periods (2021-2055 and 2056-2090) in most regions worldwide. Under the business-as-usual scenario (SSP2-4.5), the global exposure increases by ~19-fold during the late 21st century, and Africa shows the largest increase while Europe shows the smallest. Early (SSP1-2.6) and no (SSP5-8.5) actions of mitigation would relieve and aggravate the increase rate, respectively. For about 78%-87% of the global land areas, the changes in exposure are mainly caused by climate change (accounting for >69%), followed by the interaction effect (accounting for ~29%) that refers to synergistic changes in climate and population. In parts of mid- to high-latitude regions, the exposure is smaller than expected due to opposite effects of climate change and population change.
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  • 文章类型: Journal Article
    The Interstate Highway System (IHS) used to be a symbol of American growth and its economic machine, but the IHS has not been expanded much since its inception. Recently there are both executive and legislative desires to restore and upgrade the IHS to its role as a premier system that can meet the growing and changing demands of the twenty-first century. Demographic forecasting is a precursor to rational transportation planning and decision activities. This paper provides population projections into 2060 at the county level for the entire US using cohort-component methods. We found that the US is projected to experience population growth across all age groups over the next 50 years. The projected growth, however, varies across the entire US. Population growth areas are in the west/south/east border states and the Atlanta-NC-Nashville triangle. Population decline areas include many counties from the northeast corner to the Appalachian region, counties bordering the five Great Lakes, counties along the Mississippi River, the Deep South states, and Alaska. We also identified the counties that may need additional or less transport capacity based on projected population change and proximities to IHS. We further identified the counties with high population density but without the IHS network that are projected to experience rapid population growth. IHS demands will be affected by the aging population, the young population, baby boomers, millennials, immigrants, telecommuting, and autonomous vehicles. This study provides the necessary demographic forecasting for decision and policy makers in better deciding whether and where to expand or invest in the IHS when the resources become available.
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  • 文章类型: Journal Article
    The mirid bugs are one of the most important piercing-sucking insect pests in tea plantations, which severely reduce the quality and economic benefits of tea. In this study, the mirid bug species in the three tea-producing areas in Shandong Province of China were investigated. The distribution and occurrence of dominant species of mirid bugs on four weed host plants and tea plants Camellia sinensis (L.) O. Kuntze (Theaceae) were also studied in the tea agro-ecosystems. The results showed that Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) was the dominant mirid bug species in the tea growing areas. Apolygus lucorum densities on Humulus scandens (Lour.) (Moraceae) and Artemisia lavandulaefolia DC. (Asteraceae) were relatively higher than those on Conyza canadensis (Linn) Cronq (Asteraceae), Artemisia annua Linn (Asteraceae), and C. sinensis. Host plant switching of A. lucorum in the tea agro-ecosystem was: A. lucorum scattered on and seriously infested tea plants in June and July; A. lucorum largely migrated to and gathered on H. scandens, A. lavandulaefolia, C. canadensis, and A. annua at the flowering stage, and population densities of A. lucorum on these flowering hosts peaked in late September; in October, A. lucorum gradually moved back to flowering tea plants. These results could provide a reference for selecting host plants, such as Artemisia plants, as trap plants for sustainable control of mirid bugs in tea plantations.
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  • 文章类型: Journal Article
    Fine particulate (PM2.5) pollution, along with the rapid urbanization process, has been given much attention in China during the recent decades. However, the relationships between urban population dynamics and PM2.5 changes have not been well examined. We therefore analyzed their relationship using full-coverage remotely sensed PM2.5 and population density data. The results showed that 1) both population density and PM2.5 concentration increased rapidly from 2000 to 2014, especially in East and Central China, as well as China\'s high population density urban areas and the major cities; 2) A total of 723 million people was exposed to PM2.5 pollution in 2014, an increase of 105 million from 2000; 3) most of the urban areas exhibited population density increase/decrease with PM2.5 concentration increase, while a total of 42% of China\'s territory, mainly in East and Central China\'s rural areas were found to have population decrease but PM2.5 concentration increase. We hope the results in this work can serve as an example to other countries in designing their urbanization strategy by paying more attention to environmental degeneration accompanying rapid development.
    UNASSIGNED: Most of urban areas were observed to have population density increase/decrease along with PM2.5 concentration increase.
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