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Hydrochemical characteristics and evolution of groundwater in the dried-up river oasis of the Tarim Basin,Central Asia

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Journal of Arid Land 2021年第10期13卷 977-994页

作者： WANG Wanrui chen yaning WANG Weihua XIA Zhenhua li Xiaoyang Patient M KAYUMBA State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of chinese academy of sciences Beijing 100000China

Intense human activities in arid areas have great impacts on groundwater hydrochemical cycling by causing groundwater *** spatiotemporal distributions of groundwater hydrochemistry are crucial for studying groundwater salt migration,and also vital to understand hydrological and hydrogeochemical processes of groundwater in arid inland oasis ***,due to constraints posed by the paucity of observation data and intense human activities,these processes are not well known in the dried-up river oases of arid ***,we examined spatiotemporal variations and evolution of groundwater hydrochemistry using data from 199 water samples collected in the Wei-Ku oasis,a typical arid inland oasis in Tarim Basin of Central *** findings,groundwater hydrochemistry showed a spatiotemporal dynamic,while its spatial distribution was *** and δ18O of river water in the upstream increased from west to east,whereas ion concentrations of shallow groundwater increased from northwest to *** TDS was detected in spring for shallow groundwater and in summer for middle *** spatiotemporal heterogeneity demonstrated the impacts of geogenic,climatic,and anthropogenic *** that,hydrochemical evolution of phreatic groundwater was primarily controlled by rock dominance and evaporation-crystallization *** irrigation and drainage,land cover change,and groundwater extraction reshaped the spatiotemporal patterns of groundwater *** overexploitation altered the leaking direction between the aquifers,causing the interaction between saltwater and freshwater and the deterioration of groundwater *** findings could provide an insight into groundwater salt migration under human activities,and hence be significant in groundwater quality management in arid inland oasis areas.

关键词： spatiotemporal variations groundwater hydrochemistry hydrochemical evolution human activities dried-up river oasis Tarim Basin

oasis cold island effect and its influence on air temperature: a case study of Tarim Basin, Northwest china

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Journal of Arid Land 2016年第2期8卷 172-183页

作者： HAO Xingming li weihong State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences

oasis effect can improve the regional climate and habitability of an arid region. In this study, we explored the cold island effects of oases distributed along the edge of Tarim Basin by analyzing the oasis cold island effect （OCIE） intensity, spatial-temporal variation of OCIE, factors influencing the OCIE and impacts of OCIE on air temperature using geographical statistics and GIS methods based on the MODIS land surface temperature, land use/cover change （LUCC） and observed air temperature data. Results showed that all the oases in the Tarim Basin exhibited cold island effects, with the OCIE intensity highest in summer （-9.08℃）, followed by autumn （-4.24℃） and spring （-3.85℃）. The total area of oasis cold island （OCI） and the comprehensive OCIE index showed the same seasonal change trend as the OCIE intensity. However, the changing trends in areas of OCI with strong, medium and weak OCIEs were inconsistent across different seasons. Farmland and water areas were found to be the key contributors that affected the OCIE, and the area and aggregation metrics of these two land use/cover types directly contributed to the OCIE. By contrast, natural vegetation, such as forest and grassland, almost had no contribution to the OCIE. Simulation of observed air temperature data showed that if farmland is replaced by forest or grassland in the oasis, the mean, maximum and minimum air temperatures will increase significantly. This heating effect will be higher in summer （reaching 1.14℃ to 2.08℃） and lower in spring and autumn. Moreover, the heating effect of farmland being replaced by forest will be higher than that of farmland being replaced by grassland. These results can provide a basis for understanding the cold island effect of oases in arid regions.

关键词： oasis cold island effect comprehensive oasis cold island effect index landscape index oasis evolution arid environment

Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： Jian-Sheng HAO Yan WANG Lan-Hai li key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China xinjiang key laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of xinjiang Xinyuan 835800China CAS Research Center for ecology and environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(plier ***,average and maximum snow depths increased along with an increase in peak snow water equivalent,thus indicating a higher frequency of extremely scarce or abundant snow *** low snowpack temperature gradient and earlier snowmelt dates in spring lead to earlier occurrences of snowmelt floods and wet *** the risks of these events increase,they pose greater threats to farmlands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

Assessment of Crop Yield in china Simulated by Thirteen Global Gridded Crop Models

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Advances in Atmospheric sciences 2024年第3期41卷 420-434页

作者： Dezhen YIN Fang li Yaqiong LU Xiaodong ZENG Zhongda liN Yanqing ZHOU International Center for Climate and environment sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of chinese academy of sciences Beijing 100049China institute of Mountain Hazards and environment Chinese Academy of SciencesChengdu 610041China State key laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China

Global gridded crop models(GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. china is a major grain producing country, but thus far only a few studies have assessed the performance of GGCMs in china, and these studies mainly focused on the average and interannual variability of national and regional yields. Here, a systematic national-and provincial-scale evaluation of the simulations by13 GGCMs [12 from the GGCM Intercomparison(GGCMI) project, phase 1, and CLM5-crop] of the yields of four crops(wheat, maize, rice, and soybean) in china during 1980–2009 was carried out through comparison with crop yield statistics collected from the National Bureau of Statistics of china. Results showed that GGCMI models generally underestimate the national yield of rice but overestimate it for the other three crops, while CLM5-crop can reproduce the national yields of wheat, maize, and rice well. Most GGCMs struggle to simulate the spatial patterns of crop yields. In terms of temporal variability, GGCMI models generally fail to capture the observed significant increases, but some can skillfully simulate the interannual variability. Conversely, CLM5-crop can represent the increases in wheat, maize, and rice, but works less well in simulating the interannual variability. At least one model can skillfully reproduce the temporal variability of yields in the top-10 producing provinces in china, albeit with a few exceptions. This study, for the first time, provides a complete picture of GGCM performance in china, which is important for GGCM development and understanding the reliability and uncertainty of national-and provincial-scale crop yield prediction in china.

关键词： global gridded crop model historical crop yield china multi-model evaluation

Potential risks and challenges of climate change in the arid region of northwestern china

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Regional Sustainability 2020年第1期1卷 20-30页

作者： yaning chen Xueqi Zhang Gonghuan Fang Zhi li Fei Wang Jingxiu Qin Fan Sun State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi830011China University of chinese academy of sciences Beijing100049China

In the arid region of northwestern china(ARNC),water resources are the most critical factor restricting socioeconomic development and influencing the stability of the area’s ecological *** region’s complex water system and unique hydrological cycle show distinctive ***,the intensified hydrological cycle and extreme climatic and hydrological events resulting from global warming have led to increased uncertainty around water resources as well as heightened conflict between water supply and water *** of these factors are exerting growing pressures on the socioeconomic development and vulnerable ecological environment in the *** research evaluates the impacts of climate change on water resources,hydrological processes,agricultural system,and desert ecosystems in the ARNC,and addresses some associated risks and challenges specific to this *** temperature is rising at a rate of 0.31C per decade during 1961–2017 and hydrological processes are being significantly influenced by changes in glaciers,snow cover,and precipitation form,especially in the rivers recharged primarily by melt *** are also largely influenced by climate change,with the Normalized Difference Vegetation Index(NDVI)of natural vegetation exhibited an increasing trend prior to 1998,and then reversed in xinjiang while the Hexi Corridor of Gansu showed the opposite ***,the desert-oasis transition zone showed a reduction in area due to the warming trend and the recent rapid expansion of irrigated *** the warming and intensified drought are threatening agriculture *** present study could shed light on sustainable development in this region under climate change and provides scientific basis to the construction of the“Silk Road Economic Belt”.

关键词： Climate change Hydrological processes desert ecosystem Sustainable development Water resources Arid region of northwestern china Silk Road Economic Belt

新疆农田和荒漠生态系统土壤有机碳储量及其影响因素

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生态学报 2024年第14期44卷 6174-6185页

作者：杨洋张心昱苏文郭学兵唐新斋李向义李新虎马健中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室北京100101 河北建筑工程学院市政与环境工程系张家口075000 中国科学院大学资源与环境学院北京100101 中国科学院新疆生态与地理研究所乌鲁木齐830011 河北省水质工程与水资源综合利用重点实验室张家口075000

基于中国生态系统研究网络(CERN)长期监测数据,选取新疆维吾尔自治区代表暖温带干旱区的绿洲农田生态系统(阿克苏站)、代表暖温带荒漠区(策勒站)以及温带荒漠区(阜康站)的绿洲农田和荒漠生态系统综合观测场、辅助观测场和农户调查点2005... 详细信息

基于中国生态系统研究网络(CERN)长期监测数据,选取新疆维吾尔自治区代表暖温带干旱区的绿洲农田生态系统(阿克苏站)、代表暖温带荒漠区(策勒站)以及温带荒漠区(阜康站)的绿洲农田和荒漠生态系统综合观测场、辅助观测场和农户调查点2005—2020年0—100 cm土层的土壤有机碳(SOC)储量数据,分析新疆农田和荒漠生态系统SOC储量的影响因素。研究结果表明,2005—2020年0—100 cm土层SOC总储量平均值为阿克苏站(5.17 kg/m^(2))>阜康站(4.20 kg/m^(2))>策勒站(2.96 kg/m^(2))。0—20 cm、20—40 cm、40—60 cm土层的SOC分别约占0—100 cm土层储量的27.3%—35.3%、23.1%—24.6%和15.8%—17.5%。在阿克苏站,施肥量最高、灌溉量最低的农户调查点SOC储量最高;而在策勒站和阜康站,农户调查点和辅助观测场的施肥和灌溉措施分别最有利于提高SOC储量。总体来看,土壤含水量、地上生物量与SOC储量呈正相关关系;年平均气温与0—40 cm土层的SOC储量呈负相关关系。在单一生态站的生态系统尺度,年平均气温与SOC储量相关性不显著;地上生物量与策勒站和阜康站的SOC储量呈正相关关系,但是与阿克苏站0—40 cm土层的SOC储量呈负相关关系;施纯钾量与策勒站0—60 cm土层的SOC储量呈正相关关系,但与阜康站40—100 cm土层的SOC储量呈负相关关系。总之,与自然状态下的荒漠和农田不施肥相比,灌溉和施肥的农田管理措施有利于增加干旱区SOC储量。不同生态站要根据自身区域特点制定合理的农田管理模式,以维持较高的SOC储量。

关键词：土壤有机碳储量气象因素长期监测数据农田和荒漠生态系统干旱区

荒漠灌木与城市绿化灌木功能性状及其对夏季热浪响应机理的差异

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生态学报 2024年第7期44卷 2837-2848页

作者：赵鑫田陈开超李浡睿孙启兴周洁孙楠廖珂李赛强梅慧芳罗旭杨晓东宁波大学土木工程与地理环境学院宁波315211 宁波市林场宁波315440 新疆大学绿洲生态教育部重点实验室乌鲁木齐830046 新疆大学生态与环境科学学院乌鲁木齐830046

为比较干旱荒漠区城市绿化灌木和荒漠乡土灌木在夏季热浪期的受损差异和其对高温和热浪冲击响应机理的不同,在新疆北疆2022年夏季热浪期末期,测定了9种荒漠乡土灌木和8种城市绿化灌木的4种水分相关功能性状(水力、叶片、光合和碳经济性... 详细信息

为比较干旱荒漠区城市绿化灌木和荒漠乡土灌木在夏季热浪期的受损差异和其对高温和热浪冲击响应机理的不同,在新疆北疆2022年夏季热浪期末期,测定了9种荒漠乡土灌木和8种城市绿化灌木的4种水分相关功能性状(水力、叶片、光合和碳经济性状),同时调查植株受损程度。调查结果表明,荒漠乡土灌木接近74%的个体在夏季热浪中未受损伤,但有56%的城市绿化灌木个体受损;水力和叶片性状方面,荒漠灌木的枝叶水势、干物质含量和导管直径的平均值低于城市绿化植物,而枝比导率、准稳态导水率、胡伯尔值、比叶面积、导管密度呈相反态势。在碳经济和光合性状方面,荒漠乡土灌木的可溶性碳含量和水分利用效率高于城市绿化灌木(P0.05);荒漠乡土灌木的性状整合度(G=0.39)高于城市绿化植物(G=0.20),且前者的关键节点个数,以及其与其他性状显著关联的个数均高于后者。结果表明,2022年夏季热浪引起荒漠乡土灌木的受损程度低于城市绿化灌木;荒漠植物在水力性状和性状整合方面存在优势,其水分吸收、运输和减少蒸腾失水的能力要强于城市绿化灌木,热浪影响下更易存活;相对城市绿化灌木,荒漠灌木可以协调功能性状间的关系,采取更多样化的适应机理将降低夏季热浪的负面影响。本研究可为干旱地区城市绿化灌木筛选以及区域生态保护政策制定提供科学参考。

关键词：水力性状非结构性碳适应策略性状整合干旱胁迫

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Snow cover estimation from MODIS and Sentinel-1 SAR data using machine learning algorithms in the western part of the Tianshan Mountains

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Journal of Mountain Science 2020年第4期17卷 884-897页

作者： liU yang chen Xi HAO Jian-Sheng li Lan-hai State key laboratory of desert and oasis ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Ili Station for Watershed Ecosystem Research Chinese Academy of SciencesXinyuan 835800China Research Center for ecology and environment of Central Asia Chinese Academy of SciencesUrumqi 830011China xinjiang Regional Center of Resources and environmental Science Instrument Chinese Academy of SciencesUrumqi 830011China

Obtaining the spatial distribution of snow cover in mountainous areas using the optical image of remote sensing technology is difficult because of cloud and fog. In this study, the object-based principle component analysis–support vector machine(PCA–SVM) method is proposed for snow cover mapping through the integration of moderateresolution imaging spectroradiometer(MODIS) snow cover products and the Sentinel-1 synthetic aperture radar(SAR) scattering characteristics. First, derived from the Sentinel-1 A SAR images, the feature parameters, including VV/VH backscatter, scattering entropy, and scattering alpha, were used to describe the variations of snow and non-snow covers. Second, the optimum feature combinations of snow cover were formed from the feature parameters using the principle component analysis(PCA) algorithm. Finally, using the optimum feature combinations, a snow cover map with a 20 m spatial resolution was extracted by means of an object-based SVM classifier. This method was applied in the study area of the Xinyuan County, which is located in the western part of the Tianshan Mountains in xinjiang, china. The accuracies in this method were analyzed according to the data observed at different experimental sites. Results showed that the snow cover pixels of the extraction were less than those in the actual situation(FB1=93.86, FB2=59.78). The evaluation of the threat score(TS), probability of detection(POD), and false alarm ratio(FAR) for the snow-covered pixels obtained from the two-stage SAR images were different(TS1=86.84, POD1=90.10, FAR1=4.01;TS2=56.40, POD2=57.62, FAR2=3.62). False and misclassifications of the snow cover and non-snow cover pixels were found. Although the classifications were not highly accurate, the approach showed potential for integrating different sources to retrieve the spatial distribution of snow covers during a stable period.

关键词： Snow cover Estimation Sentinel-1/2 MODIS Machine learning

甘肃马先蒿入侵对巴音布鲁克草原植物群落特征的影响

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草业科学 2024年第1期41卷 1-14页

作者：黄丽菊杨磊李文超张玲卫李文军新疆农业大学资源与环境学院新疆乌鲁木齐830052 中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室新疆乌鲁木齐830011 石河子大学生命科学学院新疆石河子832003 新疆极端环境生物生态适应与进化重点实验室/新疆农业大学生命科学学院新疆乌鲁木齐830052

入侵性物种常通过竞争排斥群落中其他物种,改变入侵地群落的物种组成和结构,破坏生态系统的稳定性。甘肃马先蒿(Pedicularis kansuensis)在巴音布鲁克草原快速蔓延,对当地生态系统造成威胁,是典型的入侵性植物。本研究以入侵性植物甘肃... 详细信息

入侵性物种常通过竞争排斥群落中其他物种,改变入侵地群落的物种组成和结构,破坏生态系统的稳定性。甘肃马先蒿(Pedicularis kansuensis)在巴音布鲁克草原快速蔓延,对当地生态系统造成威胁,是典型的入侵性植物。本研究以入侵性植物甘肃马先蒿群落为研究对象,调查4个入侵程度(未入侵、低度入侵、中度入侵、高度入侵)的甘肃马先蒿群落物种组成和群落特征,分析不同入侵程度下群落的物种多样性差异。结果表明:1)甘肃马先蒿3种入侵群落中均记录了30种维管植物,未入侵群落共记录27种维管植物,3种入侵群落与未入侵群落相比均多3种植物,但多的3种植物在入侵群落中并不相同。2)甘肃马先蒿入侵降低了群落中二裂委陵菜(Potentilla bifurca)、拉普兰棘豆(Oxytropis lapponica)、紫花针茅(Stipa purpurea)、洽草(Koeleria litvinowii)、火绒草(Leontopodium leontopodioides)的重要值;禾本科的密度在群落中的比例随入侵程度的增加呈先上升后下降趋势,豆科与禾本科密度和盖度在中度和高度入侵群落中的比例显著降低(P<0.05)。3)随入侵程度增加,物种丰富度和Margalef丰富度指数呈先上升后下降趋势,Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数均呈下降-上升-下降趋势。本研究可为巴音布鲁克草原生物多样性的保护提供科学依据。

关键词：入侵性植物入侵程度物种多样性物种组成重要值优势种高寒草原