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Responses of Alpine Wetlands to Climate Changes on the Qinghai-Tibetan Plateau Based on Remote Sensing

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Chinese Geographical Science 2020年第2期30卷 189-201页

作者： WANG Rui HE Min niu zhenguo State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China

The alpine wetlands in QTP(Qinghai-Tibetan Plateau)have been profoundly impacted along with global climate *** employ satellite datasets and climate data to explore the relationships between alpine wetlands and climate changes based on remote sensing *** show that:1)the wetland NDVI(Normalized Difference Vegetation Index)and GPP(Gross Primary Production)were more sensitive to air temperature than to precipitation *** wetland ET(evapotranspiration)across alpine wetlands was greatly correlated with precipitation rate.2)Alpine wetlands responses to climate changes varied spatially and temporally due to different geographic environments,variety of wetland formation and human disturbances.3)The vegetation responses of the Zoige wetland was the most noticeable and related to the temperature,while the GPP and NDVI of the Qiangtang Plateau and Gyaring-Ngoring Lake were significantly correlated with both temperature and precipitation.4)ET in the Zoige wetland showed a significantly positive trend,while ET in Maidika wetland and the Qiangtang plateau showed a negative trend,implying wetland degradation in those two wetland *** complexities of the impacts of climate changes on alpine wetlands indicate the necessity of further study to understand and conserve alpine wetland ecosystems.

关键词： Qinghai-Tibetan Plateau(QTP) alpine wetlands climate change Moderate-resolution Imaging Spectroradiometer(MODIS) remote sensing

Comparison and assessment of NDVI time series for seasonal wetland classification

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International Journal of Digital Earth 2018年第11期11卷 1103-1131页

作者： Panpan Xu zhenguo niu Ping Tang State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingPeople’s Republic of China University of Chinese Academy of Sciences BeijingPeople’s Republic of China

Satellite-based wetland mapping faces challenges due to the high spatial heterogeneity and dynamic characteristics of seasonal *** normalized difference vegetation index(NDVI)time series(NTS)shows great potential in land cover mapping and crop classification,the effectiveness of various NTS with different spatial and temporal resolution has not been evaluated for seasonal wetland *** address this issue,we conducted comparisons of those NTS,including the moderate-resolution imaging spectroradiometer(MODIS)NTS with 500 m resolution,NTS fused with MODIS and Landsat data(MOD_LC8-NTS),and HJ-1 NDVI compositions(HJ-1-NTS)with finer resolution,for wetland classification of Poyang *** showed the following:(1)the NTS with finer resolution was more effective in the classification of seasonal wetlands than that of the MODIS-NTS with 500-m resolution and(2)generally,the HJ-1-NTS performed better than that of the fused NTS,with an overall accuracy of 88.12%for HJ-1-NTS and 83.09%for the MOD_*** work should focus on the construction of satellite image time series oriented to highly dynamic characteristics of seasonal *** study will provide useful guidance for seasonal wetland classification,and benefit the improvements of spatiotemporal fusion models.

关键词： NDVI time series seasonal wetland Poyang Lake satellite image time series

Valuation of Lake and Marsh Wetlands Ecosystem Services in China

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Chinese Geographical Science 2014年第3期24卷 269-278页

作者： ZHANG Yiran ZHOU Demin niu zhenguo XU Fengjiao Base of the State Key Laboratory of Urban Environmental Processes and Digital Modeling College of Resource Environment and Tourism Capital Normal University Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences

Wetlands are highly productive natural ecosystems, providing valuable goods and services. There is growing interest in transferring ecosystem service value from the existing wetlands studied to other wetlands ecosystems at a large geographic scale. The benefit transfer method uses the known values from wetlands to predict the value of other wetland sites. This methodology requires only limited time and resources. The present study calculated the value of the ecological services provided by lake and marsh wetlands in China in terms of biodiversity indices, water quality indices and economic indices. Basic data on wetlands were obtained through remote sensing images. The results show that: 1) The total ecosystem service value of the lake and marsh wetlands in 2008 was calculated to be 8.1841 × 1010 United States Dollars(USD), with the marsh and lake wetlands contributing 5.6329 × 1010 and 2.5512 × 1010 USD, respectively. Values of marsh ecosystem service were concentrated in Heilongjiang Province(2.5516 × 1010 USD), Qinghai Province(1.2014 × 1010 USD), and Inner Mongolia Autonomous Region(1.1884 × 1010 USD). The value of the lakes were concentrated in Tibet Autonomous Region(6.223 × 109 USD), Heilongjiang(5.810 × 109 USD), and Qinghai(5.500 × 109 USD). 2) Waste treatment and climate regulation services contributed to 26.29% and 24.74% respectively, of the total ecosystem service value of the marsh wetlands. Hydrological regulation and waste treatment contributed to 41.39% and 32.75%, respectively, of the total ecosystem service value of the lake wetlands. 3) The total ecological service value of the lake and marsh wetlands was 54.64% of the total service value of natural grassland ecosystems and 30.34% of the total service value of forests ecosystems in China.

关键词： lake wetlands marsh wetlands ecosystem services

Protection efficacy of national wetland reserves in China

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Chinese Science Bulletin 2012年第4期57卷 1116-1134页

作者： ZHENG YaoMin ZHANG HaiYing niu zhenguo GONG Peng State Key Laboratory of Remote Sensing Science Jointly Sponsored by Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China Ministry of Education Key Laboratory for Earth System Modeling Center for Earth System Science Institute for Global Change Studies Tsing- hua University Beijing 100084 China Department of Environmental Science Policy and Management University of California Berkeley California 94720-3114 USA

Wetlands have the most abundant biodiversity,the highest carbon sequestration capacity,and the highest values for ecological services per unit area,of all the world's *** has shown that establishing reserves is the most effective way of protecting typical ecosystems and their biodiversity,and saving rare or endangered *** Chinese government's policy is to protect wetland systems by establishing reserves that encompass a massive network of wetlands,including wetland nature re-serves,internationally important wetlands,and wetland *** are already *** effect of protecting wetland nature reserves at the national level has not yet been *** used the latest database evaluating the protection value of wet-land reserves,and remotely sensed wetland maps(1978-2008) ,developed by the same mapping specialists and based on the same classification system,and related environmental data,to evaluate the effects of protecting China's national wetland reserves over the last 30 *** conclude that(i) the total area of wetland in the national wetland reserves has decreased over the last 30 years to 8152.47 km2,and just 8% of China's net decrease in wetlands;(ii) about 79% of the 91 national wetland reserves are in a poor *** are generally located around the Yangtze River,Eastern Coast,the Three Rivers Source,and Southwest *** measures should be undertaken urgently in these *** 15% of national wetland reserves are under sound protection,and these are generally located in the upper reaches of the Songhua River;(iii) although 88% of national wetland re-serves are primitive(relatively natural) ,implying that the site selection has been scientific,a high percentage of national wetland reserves show early warning signs of decline and require urgent attention;(iv) based on our evaluation of protection effects and pressures on ecology,we have made a priority list of national wetland reserves,and propose several

关键词：湿地保护区中国政府湿地自然保护区生物多样性功效濒危野生动物中国西南地区生态系统

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Assessing the ecological vulnerability of protected areas by using Big Earth Data

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International Journal of Digital Earth 2021年第11期14卷 1624-1637页

作者： Yaomin Zheng Shudong Wang Yue Cao Jinlian Shi Yi Qu Liping Li Tianjie Zhao zhenguo niu Rui Yang Peng Gong School of International Economics and Management Beijing Technology and Business UniversityBeijingPeople’s Republic of China Aerospace Information Research Institute Chinese Academy of SciencesBeijingPeople’s Republic of China Institute for National Parks Tsinghua UniversityBeijingPeople’s Republic of China Department of Landscape Architecture School of ArchitectureTsinghua UniversityBeijingPeople’s Republic of China eInstitute for Culture and Tourism Development(ICTD) Beijing Technology and Business UniversityBeijingPeople’s Republic of China National and Local Joint Laboratory of Wetland and Ecological Conservation Institute of Natural Resources and EcologyHeilongjiang Academy of SciencesHarbinPeople’s Republic of China Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijingPeople’s Republic of China Ministry of Education Ecological Field Station for East Asian Migratory Birds BeijingChina Department of Geography and Department of Earth Sciences University of Hong KongHong KongPeople’s Republic of China

The ecological vulnerability of global protected areas(PAs)is linked to the 2030 United Nations Sustainable Development *** developed a novel degree of ecological vulnerability(DEV)index based on Big Earth Data to assess the ecological vulnerability of *** is a transparent,repeatable,large-scale and rapid assessment *** applied the method to case studies of International Union for Conservation of Nature(IUCN)PAs in the basins of the Aral Sea,the Caspian Sea,the Black Sea and the Lake *** 2001 and 2015,the spatial pattern of ecological vulnerability in the study area was relatively *** Caspian Sea basin and protected landscape/seascape(category V)showed high ecological vulnerability,while the Black Sea basin and wilderness areas(category Ib)showed low ecological *** Earth Data shows great vitality in PAs ecological vulnerability *** international cooperation is an important means to break the bottleneck of ecological environment and resource endowment in these important international basins.

关键词： Protected areas ecological vulnerability assessment remote sensing sustainable development goals

碳化物增强新型因瓦合金的成分优化及热处理工艺研究

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材料研究与应用 2024年第2期18卷 292-298页

作者：胡瑜牛振国栗克建朱斌艾莎吕俊杰宝武特冶航研科技有限公司重庆400080 重庆科技大学冶金与材料工程学院重庆401331

因瓦合金因其在居里温度下极低热膨胀系数的显著特性,可用于制备尺寸精度高或尺寸要求恒定的元器件,在航空航天和精密仪器等领域中受到广泛关注。然而,因瓦合金较低的强度限制了应用范围,细化晶粒、固溶强化和沉淀强化是提高因瓦合金强... 详细信息

因瓦合金因其在居里温度下极低热膨胀系数的显著特性,可用于制备尺寸精度高或尺寸要求恒定的元器件,在航空航天和精密仪器等领域中受到广泛关注。然而,因瓦合金较低的强度限制了应用范围,细化晶粒、固溶强化和沉淀强化是提高因瓦合金强度的主要途径。为制备膨胀系数低且力学强度高的高性能因瓦合金,以典型因瓦合金Fe-36Ni为研究对象,在合金熔炼中添加钒(V)和碳(C)元素,借助金相显微镜、扫描电镜、透射电镜等表征技术,研究了V、C元素添加对热轧成型因瓦合金Fe-36Ni组织形貌的影响及作用机理。研究结果表明,适量添加V和C元素,可在基体中形成细小均匀的钒碳化物(VC)颗粒,该颗粒对基体形成沉淀强化,提高了基体奥氏体组织的均匀性,从而提高了基体强度。过量添加V和C元素,不仅容易造成VC颗粒偏聚,同时还会导致合金中的Si元素在晶界聚集,形成大块硅夹杂,使合金塑性变差,热膨胀系数提高。此外,采用合理的热处理工艺,即低温固溶、超长时效的热处理方法,不仅可使VC相在合金基体组织中均匀析出,形成沉淀强化,还可避免合金中的奥氏体组织的在热处理过程中的异常长大。本研究为制备力学强度高且膨胀系数低的高性能因瓦合金提供了理论支撑。

关键词：因瓦合金 VC颗粒显微组织沉淀强化热处理工艺热轧成型力学强度膨胀系数

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

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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

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

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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

China's wetland change (1990-2000) determined by remote sensing

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Science China Earth Sciences 2010年第7期53卷 1036-1042页

作者： Peng Gong zhenguo niu Xiao Cheng KuiYi Zhao DeMin Zhou JianHong Guo Lu Liang XiaoFeng Wang DanDan Li HuaBing Huang et al. State Key Laboratory of Remote Sensing Science jointly sponsored by Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing China Institute of Northeast Geographical and Agricultural Ecology Research Chinese Academy of Sciences Changchun China Institute of Geographical Science and Resources Research Chinese Academy of Sciences Beijing China Beijing Yushi Lantu Information Technology Ltd. Beijing China

Two wetland maps for the entire China have been produced based on Landsat data acquired around 1990 and 2000. Wetlands in China have been divided into 3 broad categories with 15 sub-categories except rice fields. In 1990, the total wetland area in China was 355208 km2 whereas in 2000 it dropped to 304849 km2 with a net loss of 50360 km2. During an approximate 10-year period, inland wetland reduced from 318326 to 257922 km2, coastal wetland dropped from 14335 to 12015 km2, while artificial wetland increased from 22546 to 34911 km2. The greatest natural wetland loss occurred in Heilongjiang, Inner Mon- golia, and Jilin with a total loss of over 57000 km2 of wetland. In western China, over 13000 km2 of wetlands were newly formed in Xinjiang, Tibet, and Qinghai. About 12000 km2 of artificial wetlands were also added for fish farm and reservoir constructions. The newly formed wetlands in western China were caused primarily by climate warming over that region whereas the newly created artificial wetlands were caused by economic developments. China’s wetland loss is caused mainly by human activities.

关键词： wetland mapping natural wetland loss artificial wetland increase