随着全球城市化进程的快速发展,与之伴生的城市热岛效应给人类带来了严重的困扰,已经成为影响城市人居环境、损坏人类健康的重大现实问题。采用CiteSpace可视化工具,以中国知网(CNKI,China National Knowledge Infrastructure)收录的中...随着全球城市化进程的快速发展,与之伴生的城市热岛效应给人类带来了严重的困扰,已经成为影响城市人居环境、损坏人类健康的重大现实问题。采用CiteSpace可视化工具,以中国知网(CNKI,China National Knowledge Infrastructure)收录的中文核心期刊数据库和Web of Science(WoS)收录的英文期刊数据库为基础,从研究机构、国家、关键词及高被引文献多个角度来对2000—2022年全球城市热岛效应领域文献进行可视化数据分析。结果表明:(1)CNKI发文量在2009年到达顶点后呈现波动趋势,WoS发文量自2010年来迅速增长;(2)中国科学院为热岛效应研究领域最为活跃的机构,中国和美国为热岛效应研究领域中占据主导地位的国家;(3)近20年内热岛效应领域内研究热点内容已由早期基于气象学、地理学角度的定性分析,逐渐转变为热岛效应缓解措施、城市热岛模型等定向定量研究。展开更多
为了揭示生态修复措施对干旱半干旱地区生态系统服务的影响,以对生态可持续发展提供决策参考,基于典型的干旱半干旱地区——河北坝上地区2000年、2018年土地利用数据以及4种与生态修复措施对应的情景,结合InVEST模型分析了生态修复措施...为了揭示生态修复措施对干旱半干旱地区生态系统服务的影响,以对生态可持续发展提供决策参考,基于典型的干旱半干旱地区——河北坝上地区2000年、2018年土地利用数据以及4种与生态修复措施对应的情景,结合InVEST模型分析了生态修复措施对该区3个重要的生态系统服务(水源涵养、生境质量、碳储量)的影响。结果显示:(1)2000—2018年坝上地区土地利用变化以草地大量缩减以及林地显著扩张为主(>500 km 2),期间,水源涵养量下降7.03%,碳储量、生境质量分别增长2.82%,1.29%;(2)相比林地缓冲带、植树造林情景,开垦荒地和综合发展情景对上述3个生态系统服务的提高更为显著;(3)水源涵养、碳储量均与生境质量呈较强协同作用(r>0.42),碳储量与水源涵养呈较弱协同作用(r<0.24)。综上分析,生态修复措施能够提高坝上地区生态系统服务的供给,但以造林为主的生态修复方式在干旱半干旱地区仍需谨慎实施。展开更多
Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional v...Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional vegetation protection and drought prevention,we assessed the relations between vegetation cover change(measured by the Normalized Difference Vegetation Index,NDVI)and the Standardized Precipitation Evapotranspiration Index(SPEI)at different time-scales,in different growth stages,in different subregions and for different vegetation types based on the Pearson's correlation coefficient in the BTSSR from 2000 to 2017.Results showed that 88.19%of the vegetated areas experienced increased NDVI in the growing season;48.3%of the vegetated areas experi-enced significantly increased NDVI(P<0.05)and were mainly in the south of the BTSSR.During the growing season,a wetter climate contributed to the increased vegetation cover from 2000 to 2017,and NDVI anomalies were closely related to SPEI.The maximum correlation coefficient in the growing season(Rmax)was significantly positive(P<0.05)in 97.84%of the total vegetated areas.In the vegetated areas with significantly positive Rmax,pixels with short time-scales(1-3 mon)accounted for the largest proportion(33.9%).The sensitivity of vegetation to the impact of drought rose first and then decreased in the growing season,with a peak in July.Compared with two subregions in the south,subregions in the north of the BTSSR were more sensitive to the impacts of drought variations,especially in the Xilingol Plateau and Wuzhumuqin Basin.All four major vegetation types were sensitive to the effects of drought variations,especially grasslands.The time-scales of the most impacting droughts varied with growth stages,regions,and vegetation types.These results can help us understand the relations between vegetation and droughts,which are important for ecological restoration and drought prevention.展开更多
文摘随着全球城市化进程的快速发展,与之伴生的城市热岛效应给人类带来了严重的困扰,已经成为影响城市人居环境、损坏人类健康的重大现实问题。采用CiteSpace可视化工具,以中国知网(CNKI,China National Knowledge Infrastructure)收录的中文核心期刊数据库和Web of Science(WoS)收录的英文期刊数据库为基础,从研究机构、国家、关键词及高被引文献多个角度来对2000—2022年全球城市热岛效应领域文献进行可视化数据分析。结果表明:(1)CNKI发文量在2009年到达顶点后呈现波动趋势,WoS发文量自2010年来迅速增长;(2)中国科学院为热岛效应研究领域最为活跃的机构,中国和美国为热岛效应研究领域中占据主导地位的国家;(3)近20年内热岛效应领域内研究热点内容已由早期基于气象学、地理学角度的定性分析,逐渐转变为热岛效应缓解措施、城市热岛模型等定向定量研究。
文摘为了揭示生态修复措施对干旱半干旱地区生态系统服务的影响,以对生态可持续发展提供决策参考,基于典型的干旱半干旱地区——河北坝上地区2000年、2018年土地利用数据以及4种与生态修复措施对应的情景,结合InVEST模型分析了生态修复措施对该区3个重要的生态系统服务(水源涵养、生境质量、碳储量)的影响。结果显示:(1)2000—2018年坝上地区土地利用变化以草地大量缩减以及林地显著扩张为主(>500 km 2),期间,水源涵养量下降7.03%,碳储量、生境质量分别增长2.82%,1.29%;(2)相比林地缓冲带、植树造林情景,开垦荒地和综合发展情景对上述3个生态系统服务的提高更为显著;(3)水源涵养、碳储量均与生境质量呈较强协同作用(r>0.42),碳储量与水源涵养呈较弱协同作用(r<0.24)。综上分析,生态修复措施能够提高坝上地区生态系统服务的供给,但以造林为主的生态修复方式在干旱半干旱地区仍需谨慎实施。
基金Under the auspices of National Natural Science Foundation of China(No.41807177,41701017)the Pioneer‘Hundred Talents Program’of Chinese Academy of Sciences。
文摘Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional vegetation protection and drought prevention,we assessed the relations between vegetation cover change(measured by the Normalized Difference Vegetation Index,NDVI)and the Standardized Precipitation Evapotranspiration Index(SPEI)at different time-scales,in different growth stages,in different subregions and for different vegetation types based on the Pearson's correlation coefficient in the BTSSR from 2000 to 2017.Results showed that 88.19%of the vegetated areas experienced increased NDVI in the growing season;48.3%of the vegetated areas experi-enced significantly increased NDVI(P<0.05)and were mainly in the south of the BTSSR.During the growing season,a wetter climate contributed to the increased vegetation cover from 2000 to 2017,and NDVI anomalies were closely related to SPEI.The maximum correlation coefficient in the growing season(Rmax)was significantly positive(P<0.05)in 97.84%of the total vegetated areas.In the vegetated areas with significantly positive Rmax,pixels with short time-scales(1-3 mon)accounted for the largest proportion(33.9%).The sensitivity of vegetation to the impact of drought rose first and then decreased in the growing season,with a peak in July.Compared with two subregions in the south,subregions in the north of the BTSSR were more sensitive to the impacts of drought variations,especially in the Xilingol Plateau and Wuzhumuqin Basin.All four major vegetation types were sensitive to the effects of drought variations,especially grasslands.The time-scales of the most impacting droughts varied with growth stages,regions,and vegetation types.These results can help us understand the relations between vegetation and droughts,which are important for ecological restoration and drought prevention.
