China is ageing rapidly, and its large-scale internal migration process continues. These two interwoven processes pose serious, yet understudied, challenges for the country. Based on the 1% national population survey conducted in 2015, this study aimed to examine the scale, spatial patterns and forces driving the migration of older adults (over-60-year-olds) in China. The findings reveal that the scale of older adults' migration in China is notably smaller than that of younger people but follows a similar pattern - in that people generally migrate from the central and western regions to the eastern region and are concentrated in few destinations. Generally, older migrants have better health and socioeconomic conditions than their nonmigrant peers. The driving forces behind older adults' migration include family reunions, employment opportunities and the quality of housing, in which family reunions come first. This study not only fills the knowledge gap regarding the geography of older adults in China but also highlights the significance of 'family-led migration', thus supporting the family ties theory in a transitional country with Confucius culture.

基于35个大城市企业空间分布数据,结合Lasso和OLS回归分析模型,分析了城市空间结构多中心度和集聚度对城市PM2.5浓度的影响.结果表明,以企业空间分布表征的城市空间结构能够有效反映城市经济活动空间集聚对PM2.5浓度的影响.在控制城市社会经济和自然环境等因素后,发现多中心城市的PM2.5浓度更低,而空间结构越紧凑的城市PM2.5浓度则越高,城市空间多中心发展对PM2.5浓度的影响大于城市空间集聚度.总体来说,在中国主要的大城市中,分散化多中心城市拥有更好的空气质量.建议通过合理的城市规划和管理政策,鼓励适度分散的多中心城市发展,以实现更高的城市空气质量和更少的污染物排放.

定量评估降低室内外O3 水平带来的健康影响对O3 污染治理至关重要.本文基于室内外O3 浓度的差异性,使用城市特异性暴露因子和暴露反应模型模拟、预测满足不同室内外空气质量标准带来的健康效益情况.结果表明:①2020 年我国 337 个地级及以上城市可归因于O3 污染短期暴露和长期暴露的全因早逝人数分别为44 400 和137 237 例,相应的经济损失分别为2 375×108、7 367×108 元,分别占当年国内生产总值的 0.23%和 0.73%.②O3 浓度满足当前的《室内空气质量标准》(GB/T 18883-2022)(160 μg/m3)和《健康建筑评价标准》(T/ASC 02-2021)(112 μg/m3),无法带来健康效益,当城市每日室内O3 达标浓度分别为 60、40、30、20、10 μg/m3 时,可避免的全因早逝人数(长期暴露)分别为 90、3 931、16 191、48 861、85 584 例,相应可避免的经济损失分别为 7×108、255×108、971×108、2 787×108、4 681×108 元.③当城市每日室外O3 达标浓度分别为 160、100、80、70、60 μg/m3 时,可避免的全因早逝人数(长期暴露)分别为 6 044、46 090、78 888、100 160、124 649 例,相应可避免的经济损失分别为 355×108、2 548×108、4 298×108、5 420×108、6 700×108 元.研究显示,降低室内O3 浓度可有效减少与O3 相关的健康影响和经济损失,可率先在山东省、河南省、江苏省、广东省等地区实施更严格的区域O3 空气质量标准.

以全国城市空气质量实时发布平台的监测数据为基础,运用空间插值法模拟中国PM 2.5在10km×10km空间网格尺度上的暴露水平,利用BenMap工具估计2017年中国PM 2.5污染的健康损失,在城市尺度上对PM 2.5污染的健康经济损失进行空间分析.结果表明,在统计意义层面上,2017年PM 2.5污染共计造成我国321435例早逝、746078例住院、14877551例患病,健康经济损失约为12625亿元,占当年全国GDP的1.53％.从城市尺度来看,健康效应呈现出一定的空间聚集效应,京津冀地区城市较为严重.在空间分布上,主要以"高-高"型和"低-低"型分布为主,即健康经济损失高值城市相互聚集、健康经济损失低值城市也相互聚集,并且存在高值城市之间相互影响并逐渐向四周扩散,进而影响周围低值城市的现象.

Yin Xu, dates back more than 3,300 years, is the first relic of the capital of the Shang Dynasty literally recorded and confirmed by oracle bone scripts and the archaeological excavation in China. Located in Anyang City of Henan Province(northwestern suburbs of Huanhe banks) it covers an area of around 36 km2. According to the characteristics of Yin Xu, remote sensing has shown its great capabilities to solve many issues in different fields, e.g. visual interpretations of aerial photo were used to identify the feature of Yin Xu site in 1972, 1984, 1998, 2005 and 2010. Using the classification validated by field investigations,the change information such as the monitoring index of settlements, riverway, main roads, factory and green area can be extracted in heritage site. According to the monitoring results of land cover and the surrounding environment, we conclude that the protection planning system is effective, and the rapid expansion of neighboring building area has playing a negative role in Yin Xu protection.