检索结果-南通市图书馆

A database of global wetland validation samples for wetland mapping

在线全文

学校读者我要写书评

暂无评论

science Bulletin 2015年第4期60卷 428-434,M0003页

作者：郑姚闽牛振国宫鹏王杰 State Key Laboratory of Remote Sensing science Institute of Remote Sensing and Digital EarthChinese Academy of Sciences Ministry of Education Key Laboratory for earth system Modeling Center for Earth System ScienceInstitute for Global Change StudiesTsinghua University Joint Center for global change studies department of Environmental science Policy and ManagementUniversity of California

A database of global wetland validation samples （GWVS） is the foundation for wetland mapping on a global scale. In this work, a database of GWVS was created based on 25 “wetland-related” keyw ord searches of a total of 3,506 full-text documents downloaded from the Web of science. Eight hundred and three samples from a total of 68 countries and 14i protected areas were recorded by the GWVS, including samples of marine/coastal wetlands, inland wet- lands and human-made wetlands, at ratios of 53 %, 41% and 6 %, respectively. The results exhibit spatial distribution among Terrestrial Ecoregions of the World, the World Database on Protected Areas and the Database of global Administrative Areas. Within most of the biomes, protected areas and countries examined, the very low concentration of samples requires more attention in the future. The greatest concentration of samples within a single biome is found in the tropical and subtropical moist broadleaf forest biome, accounting for 27 % of the total samples, while no sample is found in the biome of tropical and subtropical coniferous woodland. Greater efforts are expected to be made to record samples in Oceania, Central Europe, Northern Europe, Northern Africa, Central Africa, Central America, the Caribbean, and midwestern South America. Our data show that it is feasible to map global wetlands using Landsat TM/ ETM＋ at 30-m resolution. The continued improvement of the GWVS sharing platform should be reinforced in the future, making a strong contribution to global wetland mapping and monitoring.

关键词： GWVS Remote sensing Wetlandmapping Wetland monitoring - Protected area

Forward a spatio-temporal trend surface for long-term groundmeasured albedo upscaling over heterogeneous land surface

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital earth 2018年第5期11卷 470-484页

作者： Xiaodan Wu Jianguang Wen Qing Xiao Dongqin You Qiang Liu Xingwen Lin State Key Laboratory of Remote Sensing science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingPeople’s Republic of China College of Resources and Environment University of Chinese Academy of SciencesBeijingPeople’s Republic of China Joint Center for global change studies BeijingPeople’s Republic of China College of global change and earth system science Beijing Normal UniversityBeijingPeople’s Republic of China

Upscaling ground albedo is challenged by the serious discrepancy between the heterogeneity of land surfaces and the small number of ground-based *** ground-based measurements cannot provide sufficient information on the characteristics of surface albedo at the scale of coarse pixels over heterogeneous land *** method of overcoming this problem is to introduce high-resolution albedo imagery as ancillary information for ***,due to the low frequency of updating of high-resolution albedo maps,upscaling time series of ground-based albedo measurements is *** paper proposes a method that is based on the idea of conceptual universal scaling methodology for establishing a spatiotemporal trend surface using very few high-resolution images and time series of ground-based measurements for spatial-temporal upscaling of *** construction of the spatiotemporal trend surface incorporates the spatial information provided by auxiliary remote sensing images and the temporal information provided by long time series of ground *** approach was illustrated by upscaling ground-based fine-scale albedo measurements to a coarse scale over the core study area in *** results indicate that this method can characterize the spatiotemporal variations in surface albedo well,and the overall correlation coefficient was 0.702 during the study period.

关键词： Trend surface upscaling spatiotemporal heterogeneous albedo

Upscaling in situ albedo for validation of coarse scale albedo product over heterogeneous surfaces

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Digital earth 2017年第6期10卷 604-622页

作者： Xiaodan Wu Qing Xiao Jianguang Wen Qiang Liu Dongqin You Baocheng Dou Yong Tang State Key Laboratory of Remote Sensing science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingPeople’s Republicof China College of Resourcesand Environment University of Chinese Academy of SciencesBeijingPeople’s Republic of China Joint Center for global change studies BeijingPeople’s Republic of China College of global change and earth system science Beijing Normal UniversityBeijingPeople’s Republic of China

One of the essential steps for satellite albedo validation is upscaling in situ measurements to corresponding pixel scale over relatively heterogeneous land *** the multi-scale validation strategy is applicable for heterogeneous surfaces,the calibration of the high-resolution imagery during upscaling process is never perfect,and thus the upscaling results suffer from *** regression-kriging(RK)technique can compensate the calibration part by applying kriging to upscale residuals and produce more accurate upscaling *** this paper,in situ measurements and high spatial resolution albedo imagery combined with RK technique was *** method is illustrated by upscaling surface albedo from in situ measurements scale to the coarse pixel scale in the core experimental area of HiWATER,where 17 WSN nodes were deployed at heterogeneous *** upscaling results of this method were compared with the upscaling results from multi-scale *** results show that the upscaling method based on in situ measurements and high-resolution imagery combined with RK technique can capture the spatial characteristics of surface albedo ***,an attempt was made to expand this method in time ***,a preliminary validation of the Moderate Resolution Imaging Spectroradiometer albedo product was performed as the tentative application.

关键词： Upscaling albedo heterogeneous validation in situ multi-scale

Stable classi?cation with limited sample: transferring a 30-m resolution sample set collected in 2015 to mapping 10-m resolution global land cover in 2017

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science Bulletin 2019年第6期64卷 370-373页

作者： Peng Gong Han Liu Meinan Zhang Congcong Li Jie Wang Huabing Huang Nicholas Clinton Luyan Ji Wenyu Li Yuqi Bai Bin Chen Bing Xu Zhiliang Zhu Cui Yuan Hoi Ping Suen Jing Guo Nan Xu Weijia Li Yuanyuan Zhao Jun Yang Chaoqing Yu Xi Wang Haohuan Fu Le Yu Iryna Dronova Fengming Hui Xiao Cheng Xueli Shi Fengjin Xiao Qiufeng Liu Lianchun Song Ministry of Education Key Laboratory for earth system Modeling Department of Earth System Science Tsinghua University AI for earth Lab Cross-Strait Institute Tsinghua University department of Environmental science Policy and Management University of CaliforniaBerkeley State Key Laboratory of Remote Sensing science Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Google LLC institute of Electronics Chinese Academy of Sciences United States Geological Survey National Supercomputing Center in Wuxi department of Landscape Architecture University of CaliforniaBerkeley State Key Laboratory of Remote Sensing science College of Global Change and Earth System Science Beijing Normal University National Climate Center China Meteorological Administration

As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.

关键词： the world strives to reduce timely and higher resolution information is urgently needed

Preliminary estimation of the organic carbon pool in China's wetlands

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2013年第2期58卷 662-670页

作者： ZHENG YaoMin NIU ZhenGuo GONG Peng DAI YongJiu SHANGGUAN Wei State Key Laboratory of Remote Sensing science Jointly Sponsored by Institute of Remote Sensing ApplicationsChinese Academy Sciences and Beijing Normal University Ministry of Education Key Laboratory for earth system Modeling Center for Earth System ScienceInstitute for Global Change StudiesTsinghua University department of Environmental science Policy and ManagementUniversity of California College of global change and earth system science Beijing Normal University

Accurate estimation of wetland carbon pools is a prerequisite for wetland resource conservation and implementation of carbon sink enhancement *** inventory approach is a realistic method for estimating the organic carbon pool in China's wetlands at the national *** updated data and inventory approach were used to estimate the amount of organic carbon stored in China's *** results are as follows:(1) the organic carbon pool of China's wetlands is between 5.39 and 7.25 Pg,accounting for 1.3%-3.5% of the global level;(2) the estimated values and percentages of the organic carbon contained in the soil,water and vegetation pools in China's wetlands are 5.04-6.19 Pg and 85.4%-93.5%,0.22-0.56 Pg and 4.1%-7.7%,0.13-0.50 Pg and 2.4%-6.9%,*** soil organic carbon pool of China's wetlands is greater than our previous estimate of 3.67 Pg,but is lower than other previous estimates of 12.20 and 8-10 *** on the discussion and uncertainty analysis,some research areas worthy of future attention are presented.

关键词：土壤有机碳库湿地资源中国估算不确定性分析模估计交流计数湿地土壤

Comparison of the Anthropogenic Emission Inventory for CMIP6 Models with a Country-Level Inventory over China and the Simulations of the Aerosol Properties

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric sciences 2022年第1期39卷 80-96页

作者： Tianyi FAN Xiaohong LIU Chenglai WU Qiang ZHANG Chuanfeng ZHAO Xin YANG Yanglian LI College of global change and earth system science Beijing Normal UniversityBeijing 100875China department of Atmospheric sciences Texas A&M UniversityCollege StationTexas 77843USA International Center for Climate and Environment sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China department of earth system science Tsinghua UniversityBeijing 100091China

Anthropogenic emission inventory for aerosols and reactive gases is crucial to the estimation of aerosol radiative forcing and climate ***,the anthropogenic emission inventory for AerChemMIP,endorsed by CMIP6,is briefly *** CMIP6 inventory is compared with a country-level inventory(i.e.,MEIC)over China from 1986 to *** are found in the yearly trends of the two inventories,especially after *** yearly trends of the aerosol burdens simulated by CESM2 using the two inventories follow their emission trends and deviate after the mid-2000s,while the simulated aerosol optical depths(AODs)show similar *** difference between the simulated AODs is much smaller than the difference between model and *** the simulated AODs agree with the MODIS satellite retrievals for country-wide average,the good agreement is an offset between the underestimation in eastern China and the overestimation in western ***-biased precursor gas of SO_(2),overly strong convergence of the wind field,overly strong dilution and transport by summer monsoon circulation,too much wet scavenging by precipitation,and overly weak aerosol swelling due to low-biased relative humidity are suggested to be responsible for the underestimated AOD in eastern *** indicates that the influence of the emission inventory uncertainties on simulated aerosol properties can be overwhelmed by model biases of meteorology and aerosol *** is necessary for climate models to perform reasonably well in the dynamical,physical,and chemical processes that would influence aerosol simulations.

关键词： anthropogenic emission inventory AerChemMIP CMIP6 MEIC aerosol CESM2

中新世气候适宜期构造运动加速全球海洋碳循环

在线全文

学校读者我要写书评

暂无评论

science Bulletin 2024年第6期69卷 823-832页

作者：刘丰豪杜金龙黄恩清马文涛马小林 Lucas J.Lourens 田军 State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China department of earth sciences Faculty of GeosciencesUtrecht UniversityUtrecht CB 3584Netherlands

global warming during the Miocene Climate Optimum(MCO,~17-14 million years ago)is associated with massive carbon emissions sourced from the flood basalt volcanism and ocean crustal ***,the perturbation of tectonic carbon degassing on the interaction between climate change and carbon cycle remains ***,through time-evolutive phase analysis of new and published high-resolution benthic foraminiferal oxygen(δ^(18)O)and carbon(δ^(13)C)isotope records from the global ocean,we find that variations in the marine carbon cycle lead the climate-cryosphere system(δ^(13)Clead-δ^(18)O)on 405,000-year eccentricity timescales during the *** is in contrast to the previously reported climate-lead-carbon(δ^(18)O-lead-δ^(13)C)scenario during most of the Oligo-Miocene(~34-6 million years ago).Further sensitivity analysis and model simulations suggest that the elevated atmospheric CO_(2) concentrations and the resulting greenhouse effect strengthened the low-latitude hydrological cycle during the MCO,accelerating the response of marine carbon cycle to eccentricity *** climate processes played a more important role in regulating carbon-cycle variations when earth's climate was in a warm regime,as opposed to the dominant influence of polar ice-sheet dynamics during the PlioPleistocene(after~6 million years ago).

关键词： global warming Eccentricity cycle Carbon cycle Low-latitude hydrological cycle

Using a global reference sample set and a cropland map for area estimation in China

在线全文

学校读者我要写书评

暂无评论

science China earth sciences 2017年第2期60卷 277-285页

作者： YULe LI XueCao LI CongCong ZHAO YuanYuan NIU ZhenGuo HUANG HuaBing WANG Jie CHENG YuQi LU Hui SI YaLi YU ChaoQing FU HaoHuan GONG Peng Ministry of Education Key Laboratory for earth system Modeling Center for Earth System ScienceTsinghua UniversityBeoing 100084China Joint Center for global change studies Beijing 100875China State Key Laboratory of Remote Sensing science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100101China Ministry of Education Key Laboratory for Geospatial Technology for the Middle and Lower Yellow River Regions College of Environment and Planning Henan UniversityKaifeng 475004China

A technically transparent and freely available reference sample set for validation of global land cover mapping was recently established to assess the accuracies of land cover maps with multiple *** sample set can be used to estimate areas because of its equal-area hexagon-based sampling *** capabilities of these sample set-based area estimates for cropland were investigated in this paper.A 30-m cropland map for China was consolidated using three thematic maps(cropland,forest and wetland maps)to reduce confusion between cropland and forest/*** compared three area estimation methods using the sample set and the 30 m cropland *** methods investigated were:(1)pixel counting from a complete coverage map,(2)direct estimation from reference samples,and(3)model-assisted estimation combining the map with *** results indicated that all three methods produced generally consistent estimates which agreed with cropland area measured from an independent national land use *** estimated from the reference sample set were less biased by comparing with a National Land Use Dataset of China(NLUD-C).This study indicates that the reference sample set can be used as an alternative source to estimate areas over large regions.

关键词： Cropland mapping Sampling China 30 meters

Spatial and temporal evolution of landfast ice near Zhongshan Station, East Antarctica, over an annual cycle in 2011/2012

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2019年第5期38卷 51-61页

作者： Jiechen Zhao Qinghua Yang Bin Cheng Matti Lepp?ranta Fengming Hui Surui Xie Meng Chen Yining Yu Zhongxiang Tian Ming Li Lin Zhang College of Oceanic and Atmospheric sciences Ocean University of China National Marine Environmental Forecasting Center First institute of Oceanography Ministry of Natural Resources Guangdong Province Key Laboratory for Climate change and Natural Disaster studies School of Atmospheric Sciences Sun Yat-sen University Southern Marine science and Engineering Guangdong Laboratory(Zhuhai) Finnish Meteorological institute institute of Atmospheric and earth sciences University of Helsinki College of global change and earth system sciences (GCESS) Beijing Normal University School of Geosciences University of South Florida Meteorological Service of Youyang Tujia and Miao Autonomous County College of global change and earth system sciences Beijing Normal University

Annual observations of first-year ice(FYI) and second-year ice(SYI) near Zhongshan Station, East Antarctica,were conducted for the first time from December 2011 to December 2012. Melt ponds appeared from early December 2011. Landfast ice partly broke in late January, 2012 after a strong cyclone. Open water was refrozen to form new ice cover in mid-February, and then FYI and SYI co-existed in March with a growth rate of 0.8 cm/d for FYI and a melting rate of 2.7 cm/d for SYI. This difference was due to the oceanic heat flux and the thickness of ice,with weaker heat flux through thicker ice. From May onward, FYI and SYI showed a similar growth by 0.5 cm/*** maximum thickness reached 160.5 cm and 167.0 cm, respectively, in late October. Drillings showed variations of FYI thickness to be generally less than 1.0 cm, but variations were up to 33.0 cm for SYI in March,suggesting that the SYI bottom was particularly uneven. Snow distribution was strongly affected by wind and surface roughness, leading to large thickness differences in the different sites. Snow and ice thickness in Nella Fjord had a similar "east thicker, west thinner" spatial distribution. Easterly prevailing wind and local topography led to this snow pattern. Superimposed ice induced by snow cover melting in summer thickened multi-year ice,causing it to be thicker than the snow-free SYI. The estimated monthly oceanic heat flux was ～30.0 W/m2 in March–May, reducing to ～10.0 W/m2 during July–October, and increasing to ～15.0 W/m2 in November. The seasonal change and mean value of 15.6 W/m2 was similar to the findings of previous research. The results can be used to further our understanding of landfast ice for climate change study and Chinese Antarctic Expedition services.

关键词： landfast ice thickness oceanic heat flux Prydz Bay East Antarctica