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Dissolved and emitted methane in the Poyang Lake

Science China(Technological Sciences) 2021年第1期64卷 203-212页

作者： WANG HaiZhen HUANG Rong LI JiaRui CHEN Qian MA Tao key laboratory of Water and Sediment Sciences Ministry of EducationCollege of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China School of Water resources and environment MOE Key Laboratory of Groundwater Circulation and Environmental EvolutionChina University of Geosciences(Beijing)Beijing 100083China State key laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining 810016China College of Architecture and environment Sichuan UniversityChengdu 610065China

Lake waters often act as important methane sources for global greenhouse gas emission, but it would be more complex as lakes are regulated by rivers. In this study, seasonal variations of dissolved and emitted methane in the Poyang Lake, the largest freshwater lake in China, are investigated based on a specially designed monitoring. As a typical subtropical linking-to-river lake, the Poyang shows characteristics of the "lake" in wet season and the "river" in dry season alternatively over a ***, CH_(4) flux from the Poyang Lake to the Yangtze River closes to the highest in January due to concentrated dissolved CH_(4) and "river" effects in dry season, while CH_(4) flux to the atmosphere falls to the lowest in July because of intensified CH_(4) oxidization and diluted dissolved CH_(4) as well as "lake" effects in wet season. Overall, CH_(4) fluxes from Poyang Lake to the atmosphere and to the Yangtze River were 19 and 0.35 Gg CH_(4) yr^(-1), respectively. The Three Gorges Dam, the world’s largest dam in the Yangtze River, would further intensify this pattern, enhancing the transformation between "lake phase" and"river phase". This study also provides the paradigm for CH_(4) budget from other large lakes in similar situations around the world.

关键词： CH_(4) spatiotemporal variation linking-to-river lake Poyang Lake

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Modeling of acute cadmium toxicity in solution to barley root elongation using biotic ligand model theory

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Journal of environmental Sciences 2016年第4期28卷 112-118页

作者： Xuedong Wang Mingyan Wu Jingxing Ma Xiaolin Chen Luo Hua The key Lab of Resource environment and gis College of Resource Environment and TourismCapital Normal University

Protons（H^＋）as well as different major and trace elements may inhibit cadmium（Cd）uptake in aquatic organisms and thus alleviate Cd ***,little is known about such interactions in soil *** this study,the independent effects of the cations calcium（Ca^2＋）,magnesium（Mg^2＋）,potassium（K^＋）,H^＋ and zinc（Zn^2＋）on Cd toxicity were investigated with 5-day long barley root elongation tests in nutrient *** tested concentrations of selected cations and trace metal ions were based on the ranges that occur naturally in soil pore *** toxicity of Cd decreased with increasing activity of Ca^2＋,Mg^2＋,H^＋and Zn^2＋,but not K^＋.Accordingly,conditional binding constants were obtained for the binding of Cd^2＋,Ca^2＋,Mg^2＋,H^＋,and Zn^2＋ with the binding ligand：log K（CdBL）5.19,logK（CaBL）2.87,logK（MgBL）2.98,logK（HBL）5.13 and logK（ZnBL）5.42,***,it was calculated that on average 29% of the biotic ligand sites needed to be occupied by Cd to induce a 50% decrease in root *** the estimated constants,a biotic ligand model was successfully developed to predict the Cd toxicity to barley root elongation as a function of solution *** feasibility and accuracy of its application for predicting Cd toxicity in soils were discussed.

关键词： Cadmium Biotic ligand model (BLM) Toxicity Barley

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Catalytic urea hydrolysis by composite metal oxide catalyst towards efficient urea-based SCR process:performance evaluation and mechanism investigation

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Frontiers of environmental Science & Engineering 2023年第5期17卷 67-80页

作者： Yuchen Li Zhen Chen Xiangyu Zhang Kun Yang Lidong Wang Junhua Li moe key laboratory of resources and environmental Systems Optimization Department of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China State key Joint laboratory of environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Xi’an Thermal Power Research Institute Co. Xi’an 710032China

As a promising option to provide gaseous NH_(3) for SCR system,catalytic urea hydrolysis has aroused great attention,and improving surface area and activity of catalysis are the crucial issues to be solved for efficient urea ***,a composite metal oxide(TiO_(2)@Al_(2)O_(3))catalyst was prepared by a simple hydrothermal method,with mesoporous alumina(γ-Al_(2)O_(3))as *** results verify the mesoporous structure and submicron cluster of TiO_(2)@Al_(2)O_(3),with exposed crystal faces of(101)and(400)for TiO_(2)andγ-Al_(2)O_(3),*** electronegativity difference of Ti4+and Al3+changes the charge distribution scheme around the interface,which provides abundant acid/base sites to boost the urea ***,for an optimal proportioning with nano TiO_(2)content at 10 wt.%,the hydrolysis efficiency can reach up to 35.2%at 100℃ in 2 h,increasing by~7.1%than that of the blank experiment.^(13)C NMR spectrum measurements provide the impossible intermediate species during urea *** calculations are performed to clarify the efficient H_(2)O decomposition at the interface of TiO_(2)@Al_(2)O_(3).The result offers a favorable technology for energy-efficiency urea hydrolysis.

关键词： SCR Urea hydrolysis Catalytic Water dissociation Electronegativity

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Information flow and controlling in regularization inversion of quantitative remote sensing

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Science China Earth Sciences 2005年第1期48卷 74-83页

作者： YANG Hua, XU Wangli, ZHAO Hongrui, CHEN Xue & WANG Jindi Research Center for Remote Sensing and gis, School of Geography, beijing Normal University, State key laboratory of Remote Sensing Science, beijing key laboratory for Remote Sensing of environment and Digital Cities, beijing 100875, China Department of Mathematics, beijing Normal University, beijing 100875, China Research Center for Remote Sensing and gis School of Geography Beijing Normal University State Key Laboratory of Remote Sensing Science Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing China Department of Mathematics Beijing Normal University Beijing China

In order to minimize uncertainty of the inversed parameters to the largest extent by making full use of the limited information in remote sensing data, it is necessary to understand what the information flow in quantitative remote sensing model inversion is, thus control the information flow. Aiming at this, the paper takes the linear kernel-driven model inversion as an example. At first, the information flow in different inversion methods is calculated and analyzed, then the effect of information flow controlled by multi-stage inversion strategy is studied, finally, an information matrix based on USM is defined to control information flow in inversion. It shows that using Shannon entropy decrease of the inversed parameters can express information flow more properly. Changing the weight of a priori knowledge in inversion or fixing parameters and partitioning datasets in multi-stage inversion strategy can control information flow. In regularization inversion of remote sensing, information matrix based on USM may be a better tool for quantitatively controlling information flow.

关键词： regularization inversion, information flow, Shannon entropy decrease, information matrix.

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Propagation characteristics from meteorological drought to agricultural drought over the Heihe River Basin, Northwest China

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Journal of Arid Land 2023年第5期15卷 523-544页

作者： BAI Miao LI Zhanling HUO Pengying WANG Jiawen LI Zhanjie School of Water resources and environment China University of GeosciencesBeijing 100083China moe key laboratory of Groundwater Circulation and environmental Evolution Beijing 100083China State key laboratory of Hydrology-Water resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China College of Water Sciences Beijing Normal UniversityBeijing 100875China

In the context of global warming,drought events occur *** order to better understanding the process and mechanism of drought occurrence and evolution,scholars have dedicated much attention on drought propagation,mainly focusing on drought propagation time and propagation ***,there are relatively few studies on the sensitivities of drought propagation to seasons and drought ***,we took the Heihe River Basin(HRB)of Northwest China as the case study area to quantify the propagation time and propagation probability from meteorological drought to agricultural drought during the period of 1981–2020,and subsequently explore their sensitivities to seasons(irrigation and non-irrigation seasons)and drought *** correlation coefficient method and Copula-based interval conditional probability model were employed to determine the drought propagation time and propagation *** results determined the average drought propagation time as 8 months in the whole basin,which was reduced by 2 months(i.e.,6 months)on average during the irrigation season and prolonged by 2 months(i.e.,10 months)during the non-irrigation *** probability was sensitive to both seasons and drought levels,and the sensitivities had noticeable spatial differences in the whole *** propagation probability of agricultural drought at different levels generally increased with the meteorological drought levels for the upstream,midstream,and southern downstream regions of the *** agricultural droughts were more likely to be triggered during the irrigation season,while severer agricultural droughts were occurred mostly during the non-irrigation *** research results are helpful to understand the characteristics of drought propagation and provide a scientific basis for the prevention and control of *** study is of great significance for the rational planning of local water resources and maintaining good ecological environmen

关键词： meteorological drought agricultural drought drought propagation time drought propagation probability Copula function interval conditional probability Heihe River Basin

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Unsupervised Color Segmentation with Reconstructed Spatial Weighted Gaussian Mixture Model and Random Color Histogram

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Computers, Materials & Continua 2024年第3期78卷 3323-3348页

作者： Umer Sadiq Khan Zhen Liu Fang Xu Muhib Ullah Khan Lerui Chen Touseef Ahmed Khan Muhammad Kashif Khattak Yuquan Zhang School of Computer and Information Science Hubei Engineering UniversityXiaogan432000China Institute for AI Industrial Technology Research Hubei Engineering UniversityXiaogan432000China key Lab of Mountain Hazards and Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China University of Chinese Academy of Sciences Beijing100049China College of Aviation Zhongyuan University of TechnologyZhengzhou451191China Research Center of Digital Mountain and Remote Sensing Application Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China School of Computer Science University of PoonchAzad Jammu Kashmir12350Pakistan School of Computer Science and Information Engineering Hubei UniversityWuhan430062China

Image classification and unsupervised image segmentation can be achieved using the Gaussian mixture *** the Gaussian mixture model enhances the flexibility of image segmentation,it does not reflect spatial information and is sensitive to the segmentation *** this study,we first present an efficient algorithm that incorporates spatial information into the Gaussian mixture model(GMM)without parameter *** proposed model highlights the residual region with considerable information and constructs color ***,we incorporate the content-based color saliency as spatial information in the Gaussian mixture *** segmentation is performed by clustering each pixel into an appropriate component according to the expectation maximization and maximum ***,the random color histogram assigns a unique color to each cluster and creates an attractive color by default for segmentation.A random color histogram serves as an effective tool for data visualization and is instrumental in the creation of generative art,facilitating both analytical and aesthetic *** experiments,we have used the Berkeley segmentation dataset BSDS-500 and Microsoft Research in Cambridge *** the study,the proposed model showcases notable advancements in unsupervised image segmentation,with probabilistic rand index(PRI)values reaching 0.80,BDE scores as low as 12.25 and 12.02,compactness variations at 0.59 and 0.7,and variation of information(VI)reduced to 2.0 and 1.49 for the BSDS-500 and MSRC datasets,respectively,outperforming current leading-edge methods and yielding more precise segmentations.

关键词： Unsupervised segmentation color saliency spatial weighted GMM random color histogram

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Constructing a raster-based spatio-temporal hierarchical data model for marine fisheries application

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Acta Oceanologica Sinica 2006年第1期25卷 57-63页

作者： SU Fenzhen ZHOU Chenhu ZHANG Tianyu Marine gis Center State Key Laboratory of Resources and Environmental Information System Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on gis （geographical information system）to deal with the marine information. The gis has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the gis systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional gis and its data structure. This work designed a data model, the raster-based spatio-temporal hierarchical data model （RSHDM）, for the marine information system, or for the knowledge discovery fi＇om spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse （FDW） for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels.

关键词： marine geographical information system spatio-temporal data model knowledge discovery fishery management data warehouse

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Damage evaluation of soybean chilling injury based on Google Earth Engine(GEE)and crop modelling

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Journal of Geographical Sciences 2020年第8期30卷 1249-1265页

作者： CAO Juan ZHANG Zhao ZHANG Liangliang LUO Yuchuan LI Ziyue TAO Fulu State key laboratory of Earth Surface Processes and Resource Ecology/MEM&moe key laboratory of environmental Change and Natural Hazards Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of resources and environment University of Chinese Academy of SciencesBeijing 100049China

Frequent chilling injury has serious impacts on national food security and in northeastern China heavily affects grain *** and accurate measures are desirable for assessing associated large-scale impacts and are prerequisites to disaster ***,we propose a novel means to efficiently assess the impacts of chilling injury on *** chilling injury events were diagnosed in 1989,1995,2003,2009,and 2018 in Oroqen *** total,512 combinations scenarios were established using the localized CROPGRO-Soybean ***,we determined the maximum wide dynamic vegetation index(WDRVI)and corresponding date of critical windows of the early and late growing seasons using the GEE(Google Earth Engine)platform,then constructed 1600 cold vulnerability models on CDD(Cold Degree Days),the simulated LAI(Leaf Area Index)and yields from the CROPGRO-Soybean ***,we calculated pixel yields losses according to the corresponding vulnerability *** findings show that simulated historical yield losses in 1989,1995,2003 and 2009 were measured at 9.6%,29.8%,50.5%,and 15.7%,respectively,closely(all errors are within one standard deviation)reflecting actual losses(6.4%,39.2%,47.7%,and 13.2%,respectively).The above proposed method was applied to evaluate the yield loss for 2018 at the pixel ***,a sentinel-2A image was used for 10-m high precision yield mapping,and the estimated losses were found to characterize the actual yield losses from 2018 cold *** results highlight that the proposed method can efficiently and accurately assess the effects of chilling injury on soybean crops.

关键词： chilling injury Google Earth Engine(GEE) CROPGRO-Soybean soybean yield loss cold degree days(CDD)

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A cellphone-based colorimetric multi-channel sensor for water environmental monitoring

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Frontiers of environmental Science & Engineering 2022年第12期16卷 67-78页

作者： Yunpeng Xing Boyuan Xue Yongshu Lin Xueqi Wu Fang Fang Peishi Qi Jinsong Guo Xiaohong Zhou State key laboratory of Urban Water Resource and environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China State key Joint laboratory of ESPC Center for Sensor Technology of Environment and HealthSchool of EnvironmentTsinghua UniversityBeijing100084China key laboratory of the Three Gorges Reservoir Region’s Eco-environments of moe Chongqing UniversityChongqing400030China

The development of colorimetric analysis technologies for the commercial cellphone platform has attracted great attention in environmental monitoring due to the low cost,high versatility,easy miniaturization,and widespread ownership of *** work demonstrates a cellphone-based colorimetric multi-channel sensor for quantifying multiple environmental contaminants simultaneously with high sensitivity and *** improve the sensitivity of the sensor,a delicate optical path system was created by using a diffraction grating to split six white beams transmitting through the multiple colored samples,which allows the cellphone CMOS camera to capture the diffracted light for image *** proposed sensor is a universal colorimetric detection platform for a variety of environmental contaminants with the colorimetry assay in the range of 400–700 *** introducing the diffraction grating for splitting light,the sensitivity was improved by over six folds compared with a system that directly photographed transmitted *** a successful proof-of-concept,the sensor was used to detect turbidity,orthophosphate,ammonia nitrogen and three heavy metals simultaneously with high sensitivity(turbidity:detection limit of 1.3 NTU,linear range of 5–400 NTU;ammonia nitrogen:0.014 mg/L,0.05–5 mg/L;orthophosphate:0.028 mg/L,0.1–10 mg/L;Cr(VI):0.0069 mg/L,0.01–0.5 mg/L;Fe:0.025 mg/L,0.1–2 mg/L;Zn:0.032 mg/L,0.05–2 mg/L)and reliability(relative standard deviations of six parallel measurements of 0.37%–1.60%and recoveries of 95.5%–106.0%in surface water).The miniature sensor demonstrated in-field sensing ability in environmental monitoring,which can be extended to point-of-care diagnosis and food safety control.

关键词： Colorimetric analysis Multi-channel sensor Cellphone Water quality indexes environmental monitoring

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Coupled planning of water resources and agricultural land-use based on an inexact-stochastic programming model

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Frontiers of Earth Science 2014年第1期8卷 70-80页

作者： Cong DONG Guohe HUANG Qian TAN Yanpeng CAI moe key laboratory of Regional Energy and environmental Systems Optimization Resources and Environmental Research Academy North China Electric Power University Beijing 102206 China State key laboratory of Water environment Simulation School of Environment Beijing Normal University Beijing 100875 China Institute for Energy Environment and Sustainable Communities University of Regina Saskatchewan S4S 7H9 Canada

Water resources are fundamental for support of regional development. Effective planning can facilitate sustainable management of water resources to balance socioeconomic development and water conservation. In this research, coupled planning of water resources and agricultural land use was undertaken through the develop- ment of an inexact-stochastic programming approach. Such an inexact modeling approach was the integration of interval linear programming and chance-constraint pro- gramming methods. It was employed to successfully tackle uncertainty in the form of interval numbers and probabil- istic distributions existing in water resource systems. Then it was applied to a typical regional water resource system for demonstrating its applicability and validity through generating efficient system solutions. Based on the process of modeling formulation and result analysis, the developed model could be used for helping identify optimal water resource utilization patterns and the corresponding agri- cultural land-use schemes in more, a number of decision three sub-regions. Further- alternatives were generated under multiple water-supply conditions, which could help decision makers identify desired management policies.

关键词： water resources management regional water system planning scenario analysis uncertainty

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