检索结果-南通市图书馆

Factors Influencing the spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

Advances in Atmospheric Sciences 2024年第5期41卷 817-829页

作者： Heng LYU Wei WANG Keer ZHANG Chang CAO Wei XIAO Xuhui LEE Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Ecosystem Carbon Source and SinkChina Meteorological Administration(ECSS-CMA)/Jiangsu Key Laboratory of Agricultural MeteorologyNanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Urban Meteorology China Meteorological AdministrationBeijing 100089China School of the Environment Yale UniversityNew HavenCT 06511USA

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

关键词： air temperature urban heat island spatial variations biophysical drivers Chinese cities climate model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

spatial variations of Pb,As,and Cu in surface snow along the transect from the Zhongshan Station to Dome A,East Antarctica

引用

Research in Cold and Arid Regions 2018年第3期10卷 219-231页

作者： XingXing Jiang ShuGui Hou YuanSheng Li HongXi Pang Rong Hua Mayewski Paul Sneed Sharon ChunLei An Handley Michael Ke Liu WangBin Zhang Key Laboratory for Coast and Island Development School of Geographic and Oceanographic SciencesNanjing UniversityNanjingJiangsu 210023China Polar Research Institute of China Shanghai 200136China Climate Change Institute University of MaineOronoMaine 04469USA School of Earth and Climate Sciences University of MaineOronoMaine 04469USA

The spatial distributions of lead, arsenic, and copper （Pb, As, and Cu, respectively） in surface snow along the transect from the Zhongshan Station to Dome A, East Antarctica, are presented. The mean concentrations of Pb, As, and Cu are 1.04±1.56 pg/g, 0.39±0.08 pg/g, and 11.2±14.4 pg/g, respectively. It is estimated that anthropogenic contributions are dominant for Pb, As, and Cu. spatially, Pb concentrations show an exponentially decreasing trend from the coast inland, while a moderate decreasing trend is observed for Cu concentrations in the coastal area （below 2,000 m above sea level （a.s.1.））. In the intermediate area （2,000-3,000 m a.s.1.）, the concentrations and enrichment factors of all these elements show high variability due to the complicated characteristics of climate and environment. On the inland plateau （above 3,000 m a.s.1.）, the high concentrations of As and Pb are induced by high deposition efficiency, the existence of polar stratospheric precipitation, and the different fraction deposition to East Antarctica. The extremely high concentrations with maximum values of 9.59 pg/g and 69.9 pg/g for Pb and Cu, respectively, are suggested to result mainly from local human activities at the station. Our results suggest that source, transport pathway, and deposition pattern, rather than distance from the coast or altitude, lead to the spatial distributions of Pb, As, and Cu; and it is further confirmed by spatial variations of the three metals deposited over the whole continent of Antarctica.

关键词： Antarctica surface snow trace metals spatial variations source and transportation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chemometric study of spatial variations of environmental and ecological characteristics in the Zhujiang River (Pearl River) Estuary and adjacent waters

引用

Acta Oceanologica Sinica 2011年第4期30卷 60-74页

作者： SONG Xingyu HUANG Liangmin ZHANG Jianlin YIN Kedong LIU Sheng TAN Yehui YIN Jianqiang Key Laboratory of Marine Bio-resources Sustainable Utilization South China Sea Institute of Oceanography Chinese Academy of Sciences Guangzhou 510301 China State Key Laboratory of Oceanography in the Tropics Guangzhou 510301 China Australian Rivers Institute Griffith University Brisbane 4111 Australia

Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent waters（ZREAW） in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated.

关键词： principal component analysis spatial variations environmental conditions ecological distribution phytoplankton Zhujiang River （Pearl River） Estuary

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

spatial patterns of leaf nitrogen and phosphorus stoichiometry across southeast to central Tibet

引用

Journal of Mountain Science 2022年第9期19卷 2651-2663页

作者： WANG Wei ZHAO Jia-min XING Zhen College of Resources and Environmental Sciences Tibet Agriculture&Animal Husbandry UniversityNyingchi 860000China Research institute of Tibet Plateau Ecology Tibet Agriculture&Animal Husbandry UniversityNyingchi 860000China

Leaf N and P stoichiometry in terrestrial ecosystems has been widely investigated in recent years owing to the importance of these elements in improving the predicted vegetation responses to global changes.The vertical distribution of leaf N and P stoichiometry has attracted increasing attention because of the dramatic changes in environmental factors at regional scales.However,the characteristics of leaf N and P stoichiometry in the southeast Qinghai–Tibet plateau(SET)are not clear,although this area is sensitive to global change.Here,we analyzed the leaf N and P concentrations in dominant plant species on natural altitudinal gradients on the Duoxiongla(DXL),Sejila(SJL),Mila(ML),and Gangbala(GBL)mountains across the SET all the way to central Tibet.Our results showed that the leaf N concentrations were comparable among the regions,whereas the leaf P concentrations dramatically decreased from SET to central Tibet(CT).The leaf N concentrations were 23.6,21.3,20.8,and 22.4 g kg^(-1),and the leaf P concentrations were 2.40,2.49,1.94,and 1.59 g kg^(-1) on the SJL,DXL,ML and GBL mountains,respectively.The leaf N/P ratios on the DXL,SJL,ML,and GBL mountains were 8.81,10.3,11.2,and 14.2,respectively.Considering the increasing trend of the leaf N/P ratio from southeast Qinghai–Tibet plateau to central Tibet,N limitation might widely exist in well vegetated ecosystems in the Qinghai–Tibet plateau.

关键词： Leaf N and P concentration Southeast Tibet Stoichiometry spatial variations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Global desert variation under climatic impact during 1982-2020

引用

Science China Earth Sciences 2023年第5期66卷 1062-1071页

作者： Yao CHEN Huayu LU Huijuan WU Jingjing WANG Nana LYU School of Geography and Ocean Science Frontiers Science Center for Critical Earth Material CyclingNanjing UniversityNanjing210023China

Deserts are important landscapes on the earth and their variations have impacts on global climate through feedback processes.However,there is a limited understanding of the climatic controls on the spatial and temporal variations of global deserts.Here,we use climate reanalysis datasets,global land use/land cover(LULC)products and the CMIP6(Coupled Model Intercomparison Project)model outputs to calculate the changing of global deserts during 1982-2020,and estimate future spatial trends of global deserts.Our results show that mean annual global desert area over this period is 17.64×10^(6)km^(2),accounting for 12%of the terrestrial land.Desert areas decreased rapidly from the end of the 1980s to the 1990s in North Africa and Australia,followed by a slow expansion in early 21st century globally.Spatio-temporal variations of areas of arid climate are characterized by interdecadal fluctuations,and there are clear regional differences in dynamic s of the aridity index(AI,used here as a proxy for the area of drylands)and desert areas.Statistical analyses reveal that increased vegetation cover is directly related to the reduction of desert area,while potential evaporation,surface temperature and humidity are also significantly correlated with the desert area.The relationship between wind speed and desert dynamics varies regionally.The results of the CMIP6simulations suggest that global deserts will expand in the 21st century,albeit at different rates under the ssp245 and ssp585scenarios.Desert expansions are modelled to be greatest in Asia,Africa and Australia,while those of southern North Africa may reduce as their southern borders migrate northwards.

关键词： Global desert Dryland spatial variations Climate factors CMIP6

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Field experiments on quantifying the contributions of Coreopsis canopies and roots to controlling runoff and erosion on steep loess slopes

引用

Journal of Mountain Science 2023年第5期20卷 1402-1423页

作者： GONG Yu-wei YU Hai-jun TIAN Pei GUO Wen-zhao CHEN Lin SHEN Ding-tao Key Laboratory for Geographical Process Analysis&Simulation of Hubei Province Central China Normal UniversityWuhan 430079China China Institute of Water Resources and Hydropower Research Beijing 100038China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau/Institute of Water and Soil Conservation Northwest A&F UniversityYangling 712100China Department of Environmental Sciences University of California RiversideRiversideCA 92521USA

Grass recovery is often implemented in the loess area of China to control erosion.However,the effect mechanisms of grass cover on runoff erosion dynamics on steep loess hillslopes is still not clear.Taking the typical forage species(Coreopsis)in semiarid areas as subject,this study quantified the effects of canopies and roots on controlling slope runoff and erosion.A series of field experiments were conducted in a loess hilly region of China.Field plots(5 m length,2 m width,25°slope gradient)constructed with three ground covers(bare soil;Coreopsis with intact grass;only roots of Coreopsis),were applied with simultaneous simulated rainfall(60mm h^(-1))and upslope inflow(10,30,50,70,90L min^(-1)).The results showed that compared with bare soil,intact grass significantly reduced runoff and soil loss rates by 16.6% and 62.4% on average,and decreased soil erodibility parameter by 66.3%.As inflow rate increased,the reductions in runoff and soil loss rates increased from 2.93 to 14.00 L min^(-1)and 35.11 to 121.96 g m^(-2)min^(-1),respectively.Canopies relatively contributed 66.7% to lowering flow velocity,turbulence,weakening erosive force and increasing hydraulic resistance.Roots played a predominant role in reducing soil loss and enhancing soil antierodibility,with relative contributions of 78.8% and 73.8%.Furthermore,the maximum erosion depth reduced by Coreopsis was at the upper slope section which was previously eroded the most.These results demonstrated the efficiency of Coreopsis cover in controlling runoff and erosion on steep loess slopes,especially under large inflow rates and at upper slope sections.We suggest protecting Coreopsis with intact grass at upper slope sections,while the aboveground grass biomass can be used for grazing or harvesting at middle and lower slope sections,with roots reserved.

关键词： Steep loess hillslopes Soil erosion Rill development Runoff hydraulics spatial variations Coreopsis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Multivariate analysis of surface water quality in the Three Gorges area of China and implications for water management

引用

Journal of Environmental Sciences 2011年第9期23卷 1460-1471页

作者： Jian Zhao Guo Fu Kun Lei Yanwu Li Chinese Research Academy of Environmental Sciences Beijing 100012 China.

Multivariate statistical techniques,cluster analysis,non-parametric tests,and factor analysis were applied to analyze a water quality dataset including 13 parameters at 37 sites of the Three Gorges area,China,from 2003–2008 to investigate spatio-temporal variations and identify potential pollution sources.Using cluster analysis,the twelve months of the year were classified into three periods of lowflow （LF）,normal-flow （NF）,and high-flow （HF）;and the 37 monitoring sites were divided into low pollution （LP）,moderate pollution （MP）,and high pollution （HP）.Dissolved oxygen （DO）,potassium permanganate index （COD Mn ）,and ammonia-nitrogen （NH 4 ＋-N） were identified as significant variables affecting temporal and spatial variations by non-parametric tests.Factor analysis identified that the major pollutants in the HP region were organic matters and nutrients during NF,heavy metals during LF,and petroleum during HF.In the MP region,the identified pollutants primarily included organic matter and heavy metals year-around,while in the LP region,organic pollution was significant during both NF and HF,and nutrient and heavy metal levels were high during both LF and HF.The main sources of pollution came from domestic wastewater and agricultural activities and runoff;however,they contributed differently to each region in regards to pollution levels.For the HP region,inputs from wastewater treatment plants were significant;but for MP and LP regions,water pollution was more likely from the combined effects of agriculture,domestic wastewater,and chemical industry.These results provide fundamental information for developing better water pollution control strategies for the Three Gorges area.

关键词： water quality spatial variations seasonal variations multivariate statistical techniques the Three Gorges

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：