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Spatiotemporal changes in agricultural land cover in Nepal over the last 100 years

Journal of Geographical Sciences 2018年第10期28卷 1519-1537页

作者： Basanta PAUDEL 张镱锂李士成刘林山 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS University of Chinese Academy of Sciences (UCAS) CAS Center for Excellence in Tibetan Plateau Earth Sciences School of Public Administration China University of Geosciences

In order to advance land use and land cover change（LUCC） research in Nepal, it is essential to reconstruct both the spatiotemporal distribution of agricultural land cover as well as scenarios that can explain these changes at the national and regional levels. Because of rapid population growth, the status of agricultural land in Nepal has changed markedly over the last 100 years. Historical data is used in this study, encompassing soils, populations, climatic variables, and topography. Data were revised to a series of 30 m grid cells utilized for agricultural land suitability and allocation models and were analyzed using a suite of advanced geographical tools. Our reconstructions for the spatiotemporal distribution of agricultural land in Nepal reveal an increasing trend between 1910 and 2010（from 151.2 × 10^2 km^2 to 438.8 × 10^2 km^2）. This expanded rate of increase in agricultural land has varied between different eco, physiographic, and altitudinal regions of the country, significantly driven by population changes and policies over the period of this investigation. The historical dataset presented in this paper fills an existing gap in studies of agricultural land change and can be applied to other carbon cycle and climate modeling studies, as well as to impact assessments of agricultural land change in Nepal.

关键词： agricultural land reconstruction land suitability for cultivation altitudinal variation Nepal

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280-m.y.-Old Fossil Starch Reveals Early Plant-Animal Mutulism

280-m.y.-Old Fossil Starch Reveals Early Plant-Animal Mutuli...

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第一届亚洲古生物学大会—暨中国古生物学会成立90周年纪念

作者： Feng LIU Benjamin BOMFLEUR Huiping PENG Quan LI Hans KERP Huaicheng ZHU Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences State Key laboratory of Palaeobiology ans Stratigraphy Chinese Academy of Scicneses Center for Excellence in Life and Paleoenvironment Chinese Academy of Scicneses Palaeobotany Reseaerch Group Unifersity of Munster Munster Germany Consulting Center of Stratigrpahy and Palaeontology Chinese Academy of Scicneses Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Reseach Chinese Academy of Scicneses

Starch is a major component in the human diet, and the acquisition of starch-rich food sources is considered a pivotal step in the biological and cultural evolution of ***, the potential role of starch as an energy vector in paleo-ecosystems has never been addressed, obviously due to the lack of tangible records of pre-Quaternary starch *** we describe ～280-m.y.-old lycopsid megaspores from Permian forest-swamp deposits in north China that bear caps of granular ***, shape, and surface structures as well as chemical and optical properties of these grains show that these caps are masses of compound storage *** is by far the oldest unequivocal record of fossil starch known to *** outside the actual megaspore container makes it unlikely that these starches were used for embryo nutrition;moreover, ultrathin sections of the megaspores indicate that they may have been produced after the megaspores were *** analogy to the elaiosomes on seeds of zoochorous plants today, we suggest that these starch caps were used to attract and reward animals, possibly land arthropods or snails, for megaspore *** study offers a rare glimpse into early stages of plant–animal co-evolution in Permian swamp-forest ecosystems.

关键词： Fossil starch megaspore Ealy Permian plant-animal mutulism swamp-forest ecosystem

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Characteristics of Temperature Change in China over the Last 2000 years and Spatial patterns of Dryness/Wetness during Cold and Warm Periods

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Advances in Atmospheric Sciences 2017年第8期34卷 941-951页

作者： Quansheng GE Haolong LIU Xiang MA Jingyun ZHENG Zhixin HAO Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3℃ and 0.7℃, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56°± 0.42℃（100 yr）^（-1）; however, temperatures recorded in the 20 th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD1201–70 are comparable to the present. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern： dry south of 25°N, wet from 25°–30°N, and dry to the north of 30°N. However, for all centennial cold periods, this spatial pattern also exhibits a meridional distribution. The increase in precipitation over the monsoonal regions of China associated with the 20 th century warming can primarily be attributed to a mega El Nino–Southern Oscillation and the Atlantic Multidecadal Oscillation. In addition, a significant association between increasing numbers of locusts and dry/cold conditions is found in eastern China. Plague intensity also generally increases in concert with wetness in northern China, while more precipitation is likely to have a negative effect in southern China.

关键词： temperature change dry-wet spatial pattern cold and warm periods last 2000 years China

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Unprecedented Warming Revealed from Multi-proxy Reconstruction of Temperature in Southern China for the Past 160 Years

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Advances in Atmospheric Sciences 2017年第8期34卷 977-982页

作者： Yang LIU Jingyun ZHENG Zhixin HAO Xuezhen ZHANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope（δ^（18）O）, the annual temperature anomaly in southern China during 1850–2009 is reconstructed using the method of signal decomposition and synthesis. The results show that the linear trend was 0.47℃（100 yr）^（-1）over 1871–2009,and the two most rapid warming intervals occurred in 1877–1938 and 1968–2007, at rates of 0.125℃（10 yr）^（-1）and 0.258℃（10 yr）^（-1）, respectively. The decadal variation shows that the temperature in the moderate warm interval of the 1910s–1930s was notably lower than that of the 1980s–2000s, which suggests that the warming since the 1980s was unprecedented for the past 160 years, though a warming hiatus existed in the 2000s. Additionally, there was a rapid cooling starting from the 1860s,followed by a cold interval until the early 1890s, with the coldest years in 1892 and 1893. A slight temperature decline was also found from the 1940s to the late 1960s. This study provides an independent case to validate the global warming for the past 160 years and its hiatus recently, because the proxy data are not affected by urbanization.

关键词： centennial warming temperature reconstruction multi-proxy southern China

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Impact of lockdowns and winter temperatures on natural gas consumption in Europe

arXiv

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arXiv 2021年

作者： Ciais, Philippe Bréon, François-Marie Dellaert, Stijn Wang, Yilong Tanaka, Katsumasa Gurriaran, Léna Françoise, Yann Davis, Steven Hong, Chaopeng Penuelas, Josep Janssens, Ivan Obersteiner, Michael Deng, Zhu Liu, Zhu Laboratoire des Sciences du Climat et de l'Environnement IPSL CEA CNRS UVSQ Gif sur Yvette Cedex91191 France Department of Climate Air and Sustainability TNO P.O. Box 80015 TA Utrecht3508 Netherlands Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Tsukuba305-8506 Japan Division Climat-énergies économie Circulaire Agence d'écologie Urbaine Ville de Paris Paris France Department of Earth System Science University of California Irvine 3200 Croul Hall California United States CREAF Cerdanyola del Vallès Catalonia08193 Spain Department of Biology University of Antwerp WilrijkB-2610 Belgium Ecosystems Services and Management Schlossplatz 1 LaxenburgA-2361 Austria Department of Earth System Science Tsinghua University Beijing100084 China

As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant impact on people's daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and built environment sectors during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in buildings also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe. © 2021, CC BY.

关键词： Natural gas

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Environmental Monitoring and Potential Health Risk Assessment from Pymetrozine Exposure among Communities in Typical Rice–Growing Areas of China

Research Square

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Research Square 2021年

作者： Tudi, Muyesaier Ruan, Huada Daniel Tong, Shuangmei Wang, Li Atabila, Albert Sadler, Ross Connell, Des Phung, Dung Tri Griffith University Australia Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences No. 11 Datun Road Beijing100101 China Centre for Environment and Population Health School of Medicine Griffith University 170 Kessels Road NathanQLD4111 Australia School of Environment and Science Griffith University 170 Kessels Road NathanQLD4111 Australia Beijing Normal University-Hong Kong Baptist University United International College 2000 Jintong Road Tangjiawan Guangdong Province Zhuhai China Faculty of Health Medicine and Life Sciences Maastricht University Maastricht6200 MD Netherlands College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China Department of Biological Environmental & Occupational Health Sciences School of Public Health University of Ghana P. O. Box LG13 Legon Accra Ghana

Pymetrozine is one of the most common insecticides used in China. This study was conducted to analyse Pymetrozine’s potential exposures through various environmental routes beyond the treatment area. The aim was to estimate the potential health risk for communities due to non-dietary exposure to Pymetrozine in soil and paddy water. Data on registration of pesticides in China, government reports, questionnaires, interviews, literature reviews as well as toxicological health investigations were evaluated to determine the hazard and dose-response characteristics of Pymetrozine. These were based on the US EPA exposure and human health risk assessment methods using exposure from soil and paddy water samples collected between 10 to 20 meters around the resident’s *** potential exposures from dermal contact through soil and paddy water were estimated. The potential cancer risk from the following routes was evaluated: the ingestion through soil;dermal contact exposure through soil;dermal contact exposure through paddy water;and the potential total cancer risk for residents was less than 1*10-6. These were within the acceptable risk levels. The potential hazard quotient (HQ) from acute and lifetime exposure by dermal contact through paddy water and soil;acute and lifetime exposure by soil ingestion for residents were less than 1, indicating an acceptable risk level, thus both potential cancer risk and hazard quotient (HQ) were relatively low. Potential human health risk assessment of Pymetrozine in soil and paddy water suggested that negligible cancer risk and non-cancer risk based on ingestion and dermal contact are the main potential routes of exposure to residents. © 2021, CC BY.

关键词： Soils

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A combined process coupling phytoremediation and in situ flushing for removal of arsenic in contaminated soil

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Journal of Environmental Sciences 2017年第7期29卷 104-109页

作者： Xiulan Yan Qiuxin Liu Jianyi Wang Xiaoyong Liao Beijing Key Laboratory of Environmental Damage Assessment and Remediation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Phytoremediation and soil washing are both potentially useful for remediating arsenic（As）-contaminated *** evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot *** results showed that growing Pteris vittata L.（P.v.） accompanied by soil flushing of phosphate（P.v./Flushing treatment） could significantly decrease the total As concentration of soil over a 37 day flushing period compared with the single flushing（Flushing treatment）.The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment,suggesting that the growth of *** was beneficial for promoting the removal *** analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined *** showed that comparing with the control treatment,the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing *** concentration in soil solution remained a high lever during the middle and later periods（51.26–56.22 mg/L）,which was significantly higher than the Flushing *** soil flushing of phosphate for more than a month,*** still had good accumulation and transfer capacity of As of the *** results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils.

关键词： Arsenic Soil flushing Phytoremediation Pteris vittata L. Phosphate

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Spatiotemporal Variations of Aksai Chin Lake and its influencing factors during 1972-2018

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IOP Conference Series: Earth and Environmental Science 2021年第1期783卷

作者： Wei Yan Ziyun Jiang Feng Zhou Jia Ning Shuangshuang Hou Jian Wang Rumeng Han Minghua Liu School of Urban and Planning Yancheng Teachers University Yancheng Jiangsu 224007 China School of Geographic Sciences Xinyang Normal University Xinyang Henan 46400 China College of Computer and Information Technology Xinyang Normal University Xinyang Henan 46400 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Life Sciences Guizhou University Guiyang Guizhou 550001 China

In the context of increasing lake expansion on the Tibetan Plateau, which is sensitive to climate change, it is of great significance to strengthen the research on the characteristics of lake change and its response to climate change. This paper was designed to investigate the spatiotemporal variations of Aksai Chin Lake (ACL), a typical large lake on the Tibetan Plateau, by using Landsat MSS/TM/ETM+/OLI images during 1972-2018, and to quantitatively discuss the effects of climate on lake changes based on meteorological data from Shiquanhe station. During 1961-2018, annual mean air temperature and precipitation in this region increased at rates of 0.44 °C/decade and 1.35 mm/decade, respectively, with a mutation point of 1999 for temperature, while evaporation decreased at the rate of -54.3 mm/decade, with two mutation points in 1972 and 2014, respectively. The area of ACL had increased at an average rate of 2.51 km2 per year, with a fluctuation of 'slight expansion – shrinkage – rapid expansion – slight expansion – rapid expansion' during 1972-2018. Controlled by the topography, the ACL expanded to the southeast by 3851.6 m in total. In terms of the lake area response to climate change, air temperature and evaporation were the main factors affecting ACL area directly, while precipitation mainly regulated ACL by the indirect effect through air temperature and evaporation. Generally, rising air temperature, increasing precipitation and decreasing evaporation all contribute to promote the expansion of ACL.

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Soil organic carbon dynamics in Xilingol grassland of northern China induced by the Beijing-Tianjin Sand Source Control Program

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Frontiers of Earth Science 2017年第2期11卷 407-415页

作者： Liangxia ZHANG Wei CAO Jiangwen FAN Jiangsu Key Laboratory of Agricultural Meteorology and College of Applied Meteorology Nanjing University of Information Science and Technology Nanjing 210044 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

To mitigate impacts of sandstorms on northern China, the Chinese government launched the Beijing- Tianjin Sand Source Control Program （BTSSCP） in 2000. The associated practices （i.e., cultivation, enclosure, and aerial seeding） were expected to greatly enhance grassland carbon sequestration. However, the BTSSCP-induced soil organic carbon （SOC） dynamics remain elusive at a regional level. Using the Xilingol League in Inner Mongolia for a case study, we examined the impacts from 2000 to 2006 of the BTSSCP on SOC stocks using the IPCC carbon budget inventory method. Results indicated that over all practices SOC storage increased by 1.7%, but there were large differences between practices. SOC increased most rapidly at the rate of 0.3 Mg ***-1 ＂yr-1 under cultivation, but decreased signifi- cantly under aerial seeding with moderate or heavy grazing （0.3 vs.0.6 Mg C-ha-I .yr-1）. SOC increases varied slightly for grassland types, ranging from 0.10 Mg C-ha-1 .yr-a for temperate desert steppe to 0.16 Mg ***-1 for temperate meadow steppe and lowland meadow. The overall economic benefits of the SOC sink were estimated to be 4.0 million CNY. Aerial seeding with no grazing was found to be the most cost-effective practice. Finally, we indicated that at least 55.5 years （shortest for cultivation） were needed for the grasslands to reach their potential carbon stocks. Our findings highlight the importance and effectiveness of BTSSCP in promoting terrestrial carbon sequestration which may help mitigate climate change, and further stress the need for more attention to the effective- ness of specific practices.

关键词： grassland carbon sequestration ecologicalrestoration Beijing-Tianjin Sand Source Control Program（BTSSCP） IPCC carbon budget inventory method

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Spatiotemporal patterns and characteristics of land-use change in China during 2010–2015

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Journal of Geographical Sciences 2018年第5期28卷 547-562页

作者：宁佳刘纪远匡文慧徐新良张树文颜长珍李仁东吴世新胡云锋杜国明迟文峰潘涛宁静 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Northeast Institute of Geography and Agroecology CAS Cold and Arid Regions Environmental and Engineering Research Institute CAS Institute of Geodesy and Geophysics CAS Xinjiang Institute of Ecology and Geography CAS Northeast Agricultural University

Land use/cover change is an important theme on the impacts of human activities on the earth systems and global environmental change. National land-use changes of China during 2010–2015 were acquired by the digital interpretation method using the high-resolution remotely sensed images, e.g. the Landsat 8 OLI, GF-2 remote sensing images. The spatiotemporal characteristics of land-use changes across China during 2010–2015 were revealed by the indexes of dynamic degree model, annual land-use changes ratio etc. The results indicated that the built-up land increased by 24.6×10~3 km^2 while the cropland decreased by 4.9×10~3 km^2, and the total area of woodland and grassland decreased by 16.4×10~3 km^2. The spatial pattern of land-use changes in China during 2010–2015 was concordant with that of the period 2000–2010. Specially, new characteristics of land-use changes emerged in different regions of China in 2010–2015. The built-up land in eastern China expanded continually, and the total area of cropland decreased, both at decreasing rates. The rates of built-up land expansion and cropland shrinkage were accelerated in central China. The rates of built-up land expansion and cropland growth increased in western China, while the decreasing rate of woodland and grassland accelerated. In northeastern China, built-up land expansion slowed continually, and cropland area increased slightly accompanied by the conversions between paddy land and dry land. Besides, woodland and grassland area decreased in northeastern China. The characteristics of land-use changes in eastern China were essentially consistent with the spatial govern and control requirements of the optimal development zones and key development zones according to the Major Function-oriented Zones Planning implemented during the 12 th Five-Year Plan(2011–2015). It was a serious challenge for the central government of China to effectively protect the reasonable layout of land use types dominated with the key ecological fu

关键词： land-use change spatial-temporal characteristics remote sensing Major Function-oriented Zones China

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