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Space- and ground-based CO_2 measurements： A review

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Science China Earth Sciences 2016年第11期59卷 2089-2097页

作者： yue tianxiang ZHANG LiLi ZHAO MingWei WANG YiFu John WILSON State Key Laboratory of Resources and Environment Information System Institute of Geographical Science and Natural Resources Research Beijing 100101 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210046 China Anhui Center for Collaborative Innovation in Geographical Information Integration and Application Chuzhou University Chuzhou 239012 China Spatial Sciences Institute University of Southern California Los Angles CA90089-0374 USA

The climate warming is mainly due to the increase in concentrations of anthropogenic greenhouse gases, of which CO_2 is the most important one responsible for radiative forcing of the climate. In order to reduce the great estimation uncertainty of atmospheric CO_2 concentrations, several CO_2-related satellites have been successfully launched and many future greenhouse gas monitoring missions are planned. In this paper, we review the development of CO_2 retrieval algorithms, spatial interpolation methods and ground observations. The main findings include: 1) current CO_2 retrieval algorithms only partially account for atmospheric scattering effects; 2) the accurate estimation of the vertical profile of greenhouse gas concentrations is a long-term challenge for remote sensing techniques; 3) ground-based observations are too sparse to accurately infer CO_2 concentrations on regional scales; and 4) accuracy is the primary challenge of satellite estimation of CO_2 concentrations. These findings, taken as a whole, point to the need to develop a high accuracy method for simulation of carbon sources and sinks on the basis of the fundamental theorem of Earth's surface modelling, which is able to efficiently fuse space- and ground-based measurements on the one hand and work with atmospheric transport models on the other hand.

关键词： Accuracy Carbon satellites Retrieval algorithms Space-and ground-based measurements HASM

An improved HASM method for dealing with large spatial data sets

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Science China Earth Sciences 2018年第8期61卷 1078-1087页

作者： Na ZHAO tianxiang yue Chuanfa CHEN Miaomiao ZHAO Zhengping DU State Key Laboratory of Resources and Environment Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Jiangsu Center for Collaborative Innovation in Geographic Information Resource Development and Application Nanjing 210023 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100101 China Geomatics College Shandong University of Science and Technology Qingdao 266510 China

Surface modeling with very large data sets is challenging. An efficient method for modeling massive data sets using the high accuracy surface modeling method(HASM) is proposed, and HASM_Big is developed to handle very large data sets. A large data set is defined here as a large spatial domain with high resolution leading to a linear equation with matrix dimensions of hundreds of thousands. An augmented system approach is employed to solve the equality-constrained least squares problem(LSE) produced in HASM_Big, and a block row action method is applied to solve the corresponding very large matrix equations.A matrix partitioning method is used to avoid information redundancy among each block and thereby accelerate the *** including numerical tests and real-world applications are used to compare the performances of HASM_Big with its previous version, HASM. Results show that the memory storage and computing speed of HASM_Big are better than those of HASM. It is found that the computational cost of HASM_Big is linearly scalable, even with massive data sets. In conclusion,HASM_Big provides a powerful tool for surface modeling, especially when there are millions or more computing grid cells.

关键词： Surface modeling HASM Large spatial data

A high-accuracy method for simulating the XCO_2 global distribution using GOSAT retrieval data

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Science China Earth Sciences 2017年第1期60卷 143-155页

作者： ZHAO MingWei ZHANG XingYing yue tianxiang WANG Chun JIANG Ling SUN JingLu Anhui Center for Collaborative Innovation in Geographical Information Integration and Application Chuzhou University National Satellite Meteorology Center China Meteorological Administration State Key Laboratory of Resources and Environment Information System Institute of Geographical Science and Natural Resources ResearchChinese Academy of Sciences Anhui Institute of Economics

A high-accuracy surface modeling （HASM） method based on the fimdamental theorem of surfaces, is developed to simulate XCO2 surfaces using the GOSAT retrieval XCO2 data. Two tests are designed to investigate the simulation accuracy. The first test divides the existing satellite retrieval XCO2 data into training points and testing points, and simulates the XCO2 surface using the training points while computing the simulation error using the testing points. The absolute mean error （MAE） of the testing points is 1.189 ppmv, and the corresponding values of the comparison methods, Ordinary Kriging, IDW, and Spline are 1.203, 1.301, and 1.355 ppmv, respectively. The second test simulates the XCO2 surface using all the satellite retrieval points and uses the TCCON （Total Carbon Column Observing Network） site observation values as the ture values. For the six typical TCCON sites, the HASM simulation MAE is 1.688 ppmv, and the satellite retrieval MAE at the same sites is 2.147 ppmv. These results indicate that HASM can successfully simulate XCO2 surfaces based on satellite retrieval data.

关键词： HASM GOSAT TCCON XCO2 surface

Scenarios of land cover in Eurasia under climate change

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Journal of Geographical Sciences 2020年第1期30卷 3-17页

作者： FAN Zemeng BAI Ruyu yue tianxiang State Key Laboratory of Resources and Environment Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China

The method for surface modelling of land cover scenarios(SMLCS)has been improved to simulate the scenarios of land cover in *** the basis of the observation monthly climatic data observed from 2127 weather stations in Eurasia during 1981-2010,the climatic scenarios data of RCP26,RCP45 and RCP85 scenarios released by CMIP5,and the land cover current data of Eurasia in 2010,the land cover scenarios of Eurasia were respectively *** results show that most land cover types would generally have similar changing trends in the future,but with some difference in different periods under the three scenarios of RCP26,RCP45 and *** needleleaf forest,mixed forest,shrub land,wetlands and snow and ice would generally decrease in Eurasia during *** and ice would have the fastest decreasing rate that would decrease by 37.42%on *** land would have the slowest decreasing rate that would decrease by 5.65%on *** bodies would have the fastest increasing rate that would increase by 28.78%on *** or sparsely vegetated land would have the slowest increasing rate that would increase by 0.76%.Moreover,the simulated results show that climate change would directly impact on land cover change in Eurasia.

关键词： SMLCS climate change land cover scenarios Eurasia

Sensitivity studies of a high accuracy surface modeling method

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Science China Earth Sciences 2014年第10期57卷 2386-2396页

作者： ZHAO Na yue tianxiang ZHAO MingWei DU ZhengPing FAN ZeMeng CHEN ChuanFa State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Geomatics College Shandong University of Science and Technology

The sensitivities of the initial value and the sampling information to the accuracy of a high accuracy surface modeling(HASM) are investigated and the implementations of this new modeling method are modified and enhanced. Based on the fundamental theorem of surface theory, HASM is developed to correct the error produced in geographical information system and ecological modeling process. However, the earlier version of HASM is theoretically incomplete and its initial value must be produced by other surface modeling methods, such as spline, which limit its promotion. In other words, we must use other interpolators to drive HASM. According to the fundamental theorem of surface theory, we modify HASM, namely ***, by adding another important nonlinear equation to make it independent of other methods and, at the same time, have a complete and solid theory foundation. Two mathematic surfaces and monthly mean temperature of 1951–2010 are used to validate the effectiveness of the new method. Experiments show that the modified version of HASM is insensitive to the selection of initial value which is particular important for HASM. We analyze the sensitivities of sampling error and sampling ratio to the simulation accuracy of ***. It is found that sampling information plays an important role in the simulation accuracy of ***. Another feature of the modified version of HASM is that it is theoretically perfect as it considers the third equation of the surface theory which reflects the local warping of the surface. The modified HASM may be useful with a wide range of spatial interpolation as it would no longer rely on other interpolation methods.

关键词： HASM spatial interpolation initial value sensitivity accuracy temperature

HASM quantum machine learning

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Science China Earth Sciences 2023年第9期66卷 1937-1945页

作者： tianxiang yue Chenchen WU Yi LIU Zhengping DU Na ZHAO Yimeng JIAO Zhe XU Wenjiao SHI State Key Laboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Yanqi Lake Beijing Institute of Mathematical Sciences and Applications Beijing 101408China College of Resources and Environment University of Chinese Academy of SciencesBeijing 101499China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China

The miniaturization of transistors led to advances in computers mainly to speed up their *** miniaturization has approached its fundamental ***,many practices require better computational resources than the capabilities of existing ***,the development of quantum computing brings light to solve this *** briefly review the history of quantum computing and highlight some of its advanced *** on current studies,the Quantum Computing Advantage(QCA)seems *** challenge is how to actualize the practical quantum advantage(PQA).It is clear that machine learning can help with this *** method used for high accuracy surface modelling(HASM)incorporates reinforced machine *** can be transformed into a large sparse linear system and combined with the Harrow-Hassidim-Lloyd(HHL)quantum algorithm to support quantum machine *** has been successfully used with classical computers to conduct spatial interpolation,upscaling,downscaling,data fusion and model-data assimilation of ecoenvironmental ***,a training experiment on a supercomputer indicates that our HASM-HHL quantum computing approach has a similar accuracy to classical HASM and can realize exponential acceleration over the classical algorithms.A universal platform for hybrid classical-quantum computing would be an obvious next step along with further work to improve the approach because of the many known limitations of the HHL *** addition,HASM quantum machine learning might be improved by:(1)considerably reducing the number of gates required for operating HASM-HHL;(2)evaluating cost and benchmark problems of quantum machine learning;(3)comparing the performance of the quantum and classical algorithms to clarify their advantages and disadvantages in terms of accuracy and computational speed;and(4)the algorithms would be added to a cloud platform to support applications and gather active feedback from users

关键词： Quantum computing Machine learning Eco-environmental surface High accuracy surface modelling Quantum computational advantage Practical quantum advantage

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Progress in models for coupled human and natural systems

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Science China Earth Sciences 2024年第11期67卷 3631-3637页

作者： tianxiang yue Chenchen WU Wenjiao SHI Yongzhong TIAN Qing WANG Yimin LU Lili ZHANG State Key Laboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 101408China School of Geographical Sciences Southwest UniversityChongqing 400715China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing 100021China National Engineering Research Center of Geospatial Information Technology Fuzhou UniversityFuzhou 350108China The Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China

1. Introduction Malthus (1798) was one of the earliest researchers to propose a coupled human-natural system (CHANS) model, particularly in his analysis of the relationship between population growth and food supply. He argued that while population grows geometrically, food supply increases only arithmetically, suggesting that this imbalance could eventually lead to a food crisis due to diminishing per capita food availability (Malthus, 1798).

关键词： Malthus eventually population

Virtual geographic environments for water pollution control

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International Journal of Digital Earth 2018年第4期11卷 397-407页

作者： Karsten Rink Cui Chen Lars Bilke Zhenliang Liao Karsten Rinke Marieke Frassl tianxiang yue Olaf Kolditz Department of Environmental Informatics Helmholtz Centre for Environmental ResearchLeipzigGermany Faculty of Environmental Sciences Technische Universität DresdenDresdenGermany College of Environmental Science and Engineering Tongji UniversityShanghaiPeople’s Republic of China Department of Lake Research Helmholtz Centre for Environmental ResearchMagdeburgGermany Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijingPeople’s Republic of China

Due to extensive water pollution in Chinese rivers and lakes,large efforts have to be made to improve the quality of drinking water and manage the sewage water treatment *** propose a general workflow for integrating a large number of heterogeneous data sets relating to various hydrological compartments into a Virtual Geographic Environment(VGE).This allows both researchers and stakeholders to easily access complex data collections in a unified context,find interrelations or inconsistencies between data sets and evaluate simulation results with respect to other observations or simulations in the same region.A prototype of such a VGE has been set up for the region around Chao Lake,containing more than 20 spatial data sets and collections as well as first simulation *** prototype has been successfully presented to researchers and stakeholders from China and Germany.

关键词： Scientific visualisation virtual reality hydrological modelling opengeosys data explorer VISLAB

Development of a surface modeling method for mapping soil properties

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Journal of Geographical Sciences 2012年第4期22卷 752-760页

作者： SHI Wenjiao LIU Jiyuan DU Zhengping yue tianxiang Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China

High accuracy surface modeling （HASM） is a method which can be applied to soil property interpolation. In this paper, we present a method of HASM combined geographic information for soil property interpolation （HASM-SP） to improve the accuracy. Based on soil types, land use types and parent rocks, HASM-SP was applied to interpolate soil available P, Li, pH, alkali-hydrolyzable N, total K and Cr in a typical red soil hilly region. To evaluate the performance of HASM-SP, we compared its performance with that of ordinary kriging （OK）, ordinary kriging combined geographic information （OK-Geo） and stratified kriging （SK）. The results showed that the methods combined with geographic information including HASM-SP and OK-Geo obtained a lower estimation bias. HASM-SP also showed less MAEs and RMSEs when it was compared with the other three methods （OK-Geo, OK and SK）. Much more details were presented in the HASM-SP maps for soil properties due to the combination of different types of geographic information which gave abrupt boundary for the spatial varia- tion of soil properties. Therefore, HASM-SP can not only reduce prediction errors but also can be accordant with the distribution of geographic information, which make the spatial simula- tion of soil property more reasonable. HASM-SP has not only enriched the theory of high accuracy surface modeling of soil property, but also provided a scientific method for the ap- plication in resource management and environment planning.

关键词： high accuracy surface modeling (HASM) spatial interpolation accuracy geostatistics soil properties red soil hilly legion in South China