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A new academic impact metric for evaluating geographic simulation models

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International Journal of Digital Earth 2022年第1期15卷 1855-1880页

作者： Kai Xu Min Chen Albert J.Kettner C.Michael Barton Barry F.W.Croke Anthony J.Jakeman Daniel P.Ames Hsiao-Hsuan Wang Susan M.Cuddy Songshan Yue Yongning Wen Fengyuan Zhang Yixuan Zhang Guonian Lü Key Laboratory of Virtual Geographic Environment (Ministry of Education of PRC) Nanjing Normal UniversityNanjingJiangsuPeople’s Republic of China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application NanjingJiangsuPeople’s Republic of China State Key Laboratory Cultivation Base of Geographical Environment Evolution(Jiangsu Province) NanjingJiangsuPeople’s Republic of China Community Surface Dynamics Modelling System (CSDMS) Institute of Arctic and Alpine Research (INSTAAR)University of ColoradoBoulderCOUSA School of Human Evolution and Social Change Arizona State UniversityTempeAZUSA School of Complex Adaptive Systems Arizona State UniversityTempeAZUSA institute for Water Futures Fenner School of Environment and SocietyAustralian National UniversityCanberraAustralia Mathematical Sciences institute The Australian National UniversityCanberraAustralia department of Civil and Construction Engineering Brigham Young UniversityProvoUTUSA Ecological Systems Laboratory Department of Ecology and Conservation BiologyTexas A&M UniversityCollege StationTXUSA CSIRO Land and Water CanberraAustralia

Geographic simulation models can be used to explore and better understand the geographical environment. Recent advances in geographic and socio-environmental research have led to a dramatic increase in the number of models used for this purpose. Some model repositories provide opportunities for users to explore and apply models,but few provide a general evaluation method for assessing the applicability and recognition of models. In this study,an academic impact evaluation method for models is proposed. Five indices are designed based on their pertinence. The analytical hierarchy process is used to calculate the index weights,and the academic impacts of models are quantified with the weighted sum method. The time range is controlled to evaluate the life-term and annual academic impacts of the models. Some models that met the evaluation criteria from different domains are then evaluated. The results show that the academic impact of a model can be quantified with the proposed method,and the major research areas that models impact are identified.

关键词： Geographic simulation model academic impact analytic hierarchy process model impact evaluation

The Global Stratotype Section and Point （GSSP） for the base of the Holocene Series/Epoch （Quaternary System/Period） in the NGRIP ice core

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Episodes 2008年第2期31卷 264-267页

作者： Mike Walker Sigfus Johnsen Sune Olander Rasmussen Jorgen-Peder Steffensen Trevor Popp Philip Gibbard Wim Hoek John Lowe John Andrews Svante Bjorck Les Cwynar Konrad Hughen Peter Kershaw Bernd Kromer Thomas Litt David J. Lowe Takeshi Nakagawa Rewi Newnham Jakob Schwander department of Archaeology and Anthropology University of Wales Lampeter Wales SA48 7ED UK. Centre for Ice and Climatel The Niels Bohr institute University of Copenhagen Juliane Maries Vej 30 DK2100 Copenhagen Denmark. Stable Isotope Laboratory Institute of Arctic and Alpine Research University of Colorado Boulder Co 80302 USA. department of geography University of Cambridge Downing Place Cambridge CB2 3EN UK. department-of Physical geography University of Utrecht Heidelberglaan 2 3508 TC Utrecht The Netherlands. department of geography Royal Holloway University of London Egham Surrey TW20 0EX UK. institute for arctic and alpine research University of Colorado Campus Box 450 Boulder Co 80309 USA. GeoBiosphere Science Centre Quaternary Sciences Lund University S/51veg 12 SE-223 62 Lund Sweden. department of Biology University of New Brunswick Fredericton New Brunswick Canada E3B 6E1. department of Marine Chemistry and Geochemistry Woods Hole Oceanographic Institution Woods Hole MA 02543 USA. School of geography and Environmental Science Monash University Victoria 3800 Australia. Heidelberg Academy of Sciences University of Heidelberg 1NF 229 D-69120 Heidelberg Germany. institute for Palaeontology University of Bonn Nussallee 8 D-53115 Bonn Germany. department of Earth and Ocean Sciences University of Waikato Private Bag 3105 Hamilton New Zealand. department of geography University of Newcastle Newcastle-upon-Tyne NE 1 7RU UK. School of geography University of Plymouth Drake Circus Plymouth PIA 8AA UK. Climate and Environmental Physics Physics Institute University of Bern Sidlerstrasse 5 CH-3012 Bern Switzerland.

The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene-Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/ Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ18O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi-parameter annual layer counting provides an age of 11,700 yr b2k (before AD2000) for the base of the Holocene, with an estimated 2σ uncertainty of 99 yr. It is proposed that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period).

关键词：地球全新世第四纪地质时代周期

Spatial distribution of morphometric parameters of glacial cirques in the Central Pyrenees(Aran and Boí valleys)

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Journal of Mountain Science 2018年第10期15卷 2103-2119页

作者： Luis LOPES Marc OLIVA Marcelo FERNANDES Paulo PEREIRA Pedro PALMA Jesús RUIZ-FERNáNDEZ Centre for Geographical Studies – IGOT Universidade de Lisboa department of geography University of Barcelona Environmental Management Center Mykolas Romeris University department of geography University of Oviedo

Glacial cirques are typical landscape features of mid-latitude mountain environments like the Central Pyrenees. Their morphology as well as their spatial distribution provides insights about past glaciers and climates. In this study, we examine the distribution, morphometrical and topographical characteristics of glacial cirques in two U-shaped glacial valleys located in the Central Pyrenees – the Aran and the Boí valleys. They are located in different aspects of this mountain range(north vs south) under different climatic influences that promoted distinct glaciation patterns during the late Pleistocene. The spatial mapping of these landforms was carried out using high-resolution imagery and field observations. We analysed the data of the morphometrical and topographical variables of the glacial cirques by using different statistical and geospatial methods in order tounveil the factors controlling their formation and development. A total of 186 glacial cirques were mapped in the study area, including 119 in the Aran and 67 in the Boí valleys. The local topography and microclimate conditions lead to substantial differences in both areas in terms of the morphology and dimensions of the cirques. Glacial cirques in Boí are distributed at slightly higher elevations than in Aran and they are also larger, though their dimensions decrease with elevation in both valleys. Aran cirques are mostly oriented NE, while Boí landforms do not show any prevailing aspect. Even though lithology does not control the distribution of the glacial cirques, some specific lithological settings may favour the development of larger cirques. In general, glacial cirques in the Aran and the Boí valleys show morphometrical properties similar to those reported in other mid-latitude mountain ranges.

关键词：冰斗冰川山谷山脉分发中央空间小气候条件

Improved alpine grassland mapping in the Tibetan Plateau with MODIS time series: a phenology perspective

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International Journal of Digital Earth 2015年第2期8卷 133-152页

作者： Cuizhen Wang Huadong Guo Li Zhang Yubao Qiu Zhongchang Sun Jingjuan Liao Guang Liu Yili Zhang Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingChina department of geography University of South CarolinaColumbiaUSA institute of Geographic Sciences and Natural Resources research Chinese Academy of SciencesBeijingChina

The Tibetan Plateau is primarily composed of alpine *** distributions of alpine grasses,however,are not well documented in this remote,highly uninhabited *** advantage of the frequently observed moderate resolution imaging spectroradiometer(MODIS)images(500-m,8-day)in 2010,this study extracted the phenological metrics of alpine grasses from the normalized difference vegetation index time *** the Support Vector Machine,a multistep classification approach was developed to delineate alpine meadows,steppes,and desert *** lakes,permanent snow,and barren/desert lands were also classified with a MODIS scene acquired in the peak growing *** ground data collected in the field and aerial experiments in 2011,the overall accuracy reached 93%when alpine desert grasses and barren lands were not *** comparison with the recently published national vegetation map,the alpine grassland map in this study revealed smoother transition between alpine meadows and steppes,less alpine meadows in the southwest,and more barren/deserts in the high-cold Kunlun Mountain in the *** variations better reflected climate control(***)of different climatic divisions on alpine *** improved alpine grassland map could provide important base information about this cold region under the pressure of rapidly changing climate.

关键词： Tibetan Plateau alpine grassland time-series analysis SVM

The uptake diversity of soil nitrogen nutrients by main plant species in Kobresia humilis alpine meadow on the Qinghai-Tibet Plateau

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Science China Earth Sciences 2012年第10期55卷 1688-1695页

作者： WANG WenYing MA YongGui XU Jin WANG HuiChun ZHU JinFu ZHOU HuaKun department of Life and geography Sciences Qinghai Normal University Xining 810008 China Northwest institute of Plateau Biology Chinese Academy of Sciences Xining 810008 China Center for Agricultural Resources research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 China

We studied the uptake of ammonium,nitrate,and a variety of amino acids by alpine plant species in the Kobresia humilis alpine meadow ecosystem in *** examined the extent of niche separation in uptake of N source by different plant species in alpine communities,and investigated the contribution of symbiotically fixed N to the total N in alpine *** results are(1) δ 15 N natural abundance values of 13 plant species lie between 2.680‰ and 5.169‰,and the scope is 7.849‰.(2) Leguminous plants,such as Trigonella ruthenica,Gueldenstaedtia diversiffolia,and Oxytyopis ochrocephala,and non-leguminous plant Gentiana straminea uptake low amounts of 15 N labeled ammonium,nitrate,glycine or aspartate in soil.(3) As far as the plant uptake of organic N is concerned,Kobresia humilis,Poa pratensis,and Gentiuna spathutifolta can effectively uptake organic nitrogen,and about 37%-40% of the nitrogen of these species comes from soil organic nitrogen sources(such as glycine and aspartate).Stipa aliena can effectively uptake nitrate,and 60% of its nitrogen comes from soil *** anserina,Poa pratensis,and Thalictrum alpinum can effectively absorb ammonium in comparason to other plant species in the meadow,and about 25%-27% of the nitrogen in these plants comes from soil ammonium.(4) The contribution of leguminous fixed N to total N is 7.48%-9.26% in Kobresia humilis alpine meadow.(5) These data show many plant species of alpine meadow may effectively utilize dissolved organic nitrogen such as amino acids,and these plants have diverse ways to uptake soil nitrogen in alpine *** on the results we can partly explain why there are abundant biodiversities and how plants at alpine habitat utilize the limited soil N sources.

关键词：高寒草甸生态系统土壤有机氮植物吸收氮素养分矮嵩草物种多样性青藏高原土壤硝酸盐

从木材解剖学视角看公元6世纪中期晚古小冰期的开始时间

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Science Bulletin 2022年第22期67卷 2336-2344页

作者： Ulf Büntgen Alan Crivellaro Dominique Arseneault Mike Baillie David Barclay Mauro Bernabei Jarno Bontadi Gretel Boswijk David Brown Duncan AChristie Olga VChurakova Edward RCook Rosanne D’Arrigo Nicole Davi Jan Esper Patrick Fonti Ciara Greaves Rashit MHantemirov Malcolm KHughes Alexander VKirdyanov Paul JKrusic Carlos Le Quesne Fredrik CLjungqvist Michael McCormick Vladimir SMyglan Kurt Nicolussi Clive Oppenheimer Jonathan Palmer 秦春 Frederick Reinig Matthew Salzer Markus Stoffel Max Torbenson Mirek Trnka Ricardo Villalba Nick Wiesenberg Greg Wiles 杨保 Alma Piermattei department of geography University of CambridgeCambridge CB23ENUK Swiss Federal research institute(WSL) Birmensdorf 8903Switzerland Global Change research Centre(CzechGlobe) Brno 60300Czech Republic department of geography Faculty of ScienceMasaryk UniversityBrno 61300Czech Republic Forest Biometrics Laboratory Faculty of Forestry“Stefan cel Mare”University of SuceavaSuceava 720229Romania department of Biology Chemistry and GeographyUniversity of Quebec in RimouskiRimouski Qc.G5L 3A1Canada Archaeology&Palaeoecology School of Natural and Built EnvironmentQueen’s University BelfastBelfast BT71NNUK department of Geology State University of New York at CortlandCortland NY 13045USA CNR-IBE Institute of BioEconomyNational Research CouncilTrento 38121Italy School of Environment The University of AucklandAuckland 1010New Zealand Laboratorio de Dendrocronología y Cambio Global Universidad Austral de ChileValdivia 509000Chile Center for Climate and Resilience research(CR) Santiago 8370449Chile Cape Horn International Center(CHIC) Punta Arenas 6200000Chile institute of Ecology and geography Siberian Federal UniversityKrasnoyarsk 660041Russia Tree-Ring Laboratory Lamont-Doherty Earth ObservatoryColumbia UniversityPalisades NY 10964USA department of Environmental Science William Paterson UniversityWayne NJ 07470USA department of geography Johannes Gutenberg UniversityMainz 55099Germany institute of Plant and Animal Ecology Ural BranchRussian Academy of SciencesYekaterinburg 620144Russia Ural institute of Humanities Ural Federal UniversityYekaterinburg 620002Russia Laboratory of Tree-Ring research University of ArizonaTucson AZ 85721USA Sukachev institute of Forest SB RAS Krasnoyarsk 660036Russia department of Physical geography Bolin Centre for Climate ResearchStockholm UniversityStockholm 10691Sweden department of History Stockholm UniversityStockholm 10691Sweden Bolin Centre for Climate research Stockholm UniversityStockholm 10691Sweden Swedish Collegium for Advanced Study

公元536~540年间的大规模火山喷发使得晚古小冰期成为过去两千年最为寒冷的时期.然而,受限于现有气候代用资料的时间分辨率和空间覆盖度,晚古小冰期的开始时间和空间范围仍存有争议.本文分析了全球23个森林样点、20个树种的106个树轮样... 详细信息

公元536~540年间的大规模火山喷发使得晚古小冰期成为过去两千年最为寒冷的时期.然而,受限于现有气候代用资料的时间分辨率和空间覆盖度,晚古小冰期的开始时间和空间范围仍存有争议.本文分析了全球23个森林样点、20个树种的106个树轮样本资料,从细胞尺度揭示了公元530~550年间北半球发生的短暂夏季冷却现象.经过交叉定年和染色处理后,在北半球的树轮样品中共识别出89个蓝轮(缺失细胞壁木质化过程)、9个霜轮(细胞分裂受阻)和93个浅轮(细胞壁增厚减弱).研究结果表明,公元536年7月中旬至8月初期间整个北美和欧亚大陆均发生了最剧烈的温度下降,而更多的区域性“冷夏”出现于公元532年、540~543年和548年.然而,本研究在南半球的树轮资料中并未发现异常的解剖结构,其原因可能与南半球的海洋热惯性减缓了火山降温效应有关,也或与南半球其时正值非生长季有关.相较于传统的树轮年代学方法,本研究的木材解剖学的方法能为地球系统模式提供更为精细的参考标准,有望服务于气候与人类历史交叉学科研究,同时对“全球气候平均”概念的使用提出质疑.

关键词：地球系统模式小冰期火山喷发树轮年代学全球气候欧亚大陆冷夏染色处理

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加拿大北极地区航运对气候变暖的影响

Journal of Geographical Sciences 2021年第3期31卷 369-388页

作者： Mian Sabir HUSSAIN Inhye HEO Sujeong IM Seungho LEE Climate research institute Konkuk UniversitySeoulKorea department of geography Konkuk UniversitySeoulKorea

This paper presents a detailed account of the effect of shipping activity on the increasing trends of air temperatures in the Canadian arctic region for the period of 1980–*** trend of temperature has gained significant attention with respect to shipping activities and sea ice area in the Canadian ***,sea ice area and shipping traffic datasets were investigated,and simple linear regression analyses were conducted to predict the rate of change(per decade)of the average temperature,considering winter(January)and summer(July)*** results indicate that temperature generally increased over the studied *** warming trend was observed during July,with an increase of up to 1℃,for the Canadian arctic *** increasing trend of temperature was observed during July from the lower to higher *** increase in temperature during July is speculated to increase the melting of *** also show a decline in sea ice area has a significant positive effect on the shipping traffic,and the numbers of marine vessel continue to increase in the *** increase in temperature causes the breaking of sea ice due to shipping activities over northern arctic Canada.

关键词： shipping activity increasing trend of temperature sea ice area Canadian arctic

Effects of elevation on spring phenological sensitivity to temperature in Tibetan Plateau grasslands

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Chinese Science Bulletin 2014年第34期59卷 4856-4863页

作者： Lingling Liu Liangyun Liu Liang Liang Alison Donnelly Isaac Park Mark D.Schwartz institute of Remote Sensing and Digital Earth Chinese Academy of Sciences University of Chinese Academy of Sciences department of geography University of Wisconsin-MilwaukeeMilwaukee WI 53201-0413 USA department of geography University of Kentucky LexingtonKY 40506-0027 USA

Vegetation phenology is an important indicator of climate change impacts on the seasonal dynamics of the biosphere. However, little is known about the influence of elevation on spring phenological sensitivity to temperature in an alpine ecosystem. Based on remotely sensed land surface phenology and temperature data from 2001 to2010, this study investigated the rate of spring phenological change of the Tibetan Plateau(TP) grasslands in response to interannual temperature variations at different elevations. Results suggest that spring phenology in the TP grasslands exhibits a stronger response to changes in temperature at higher elevations than at lower ones. In particular, spring phenology advanced by 1–2 days in response to a 1 °C increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to8–9 days/°C at 5,000–5,500 m. Analysis using accumulated growing degree days(AGDD) from January 1through May 31 showed the same general trend with increased elevation associated with increased sensitivity(as measured by phenological change per unit of AGDDchange). Such temperature sensitivity gradients in the TP grasslands could be partly explained by the growth efficiency hypothesis which suggests that vegetation adapted to colder climates likely requires less heat energy for the onset of growing season and vice versa in warmer ***, accumulated growing degree days from January 1 to the greenup date were found to decrease with increasing elevations, which provided evidence to support the applicability of the growth efficiency hypothesis in an alpine grassland ecosystem.

关键词：植被物候海拔高度温度数据青藏高原敏感性草原气候变化影响高山生态系统

Uncertainty in water resources:introduction to the specia column

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Frontiers of Earth Science 2018年第4期12卷 649-652页

作者： S.R.FASSNACHT R.W.WEBB M.MA ESS-Watershed Science Colorado State UniversityFort CollinsCO 80523-1476USA Cooperative institute for research in the Atmosphere Fort CollinsCO 80523-1375USA Natural Resources Ecology Laboratory Fort CollinsCO 80523-1499USA institute of arctic and alpine research University of Colorado BoulderBoulderCO 80309-0450USA now with department of Civil Constructionand Environmental EngineeringUniversity of New MexicoAlbuquerqueNM 87131USA research Base of Karst Eco-environments at Nanehuan in Chongqing Ministry of Nature ResourcesSchool of Geographical SciencesSouthwest UniversityChongqing 400715China

Uncertainty is a defining problem in the understanding of earth systems, especially for water resources (Guillaume et al., 2017). The word “uncertainty” can have a variety of meanings (Montanari, 2007; Beven, 2016). Typically, we only understand processes in the confines of laboratory experiments, on a very fine scale in the field, or in vague generalities. This is often the case because the processes are not well understood, or there is not enough data at the appropriate resolution or over a sufficient extent. Scaling issues occur at both spatial and temporal resolution leaving the scientist with imperfect knowledge of a system and poorly defined errors when evaluating it.

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