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Seasonal patterns of spatial differentiation of landcover change in China

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Chinese Science Bulletin 1999年第4期44卷 362-364页

作者： CHEN Yufengstate key laboratory of Resource and environment information system , institute of geography, Chinese Academy of Sciences, Beijing 100101, China state key laboratory of Resource and environment information system Institute of Geography Chinese Academy of Sciences Beijing China

Using the 1°×1° NOAA AVHRR NDVI data set in China, an index on the spatial different gradient of landcover is created. Then based on the index and supported by the geographical information system, it is revealed through principal component and factor analyses methods that there exist four types of seasonal patterns of spatial differentiation of landcover change in China, i.e. November to next March type, June to September type, May or October type and April type.

关键词： landcover spatial differentiation seasonal pattern.

Spatial distribution of copper content in sediments of the Yangtze River system

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Chinese Science Bulletin 1997年第15期42卷 1294-1297页

作者： Zhang, CS Zhang, S He, JB state key laboratory of Resources and environment information system China Department of Chemical geography Institute of Geography Chinese Academy of Sciences Beijing China

THE spatial distribution pattern of an element content is controlled by various geochemical pro-cesses. Studies on the spatial pattern are beneficial to further analysis on the factors. As a re-sult, our knowledge about the geochemical processes is enriched. At the same time, describingthe spatial patterns quantitatively with some indices is one way from qualitative to quantitativeanalysis.

关键词： geostatistics variogram Kriging copper.

Mapping Soil Salinity Using a Similarity-based Prediction Approach:A Case Study in Huanghe River Delta,China

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Chinese Geographical Science 2015年第3期25卷 283-294页

作者： YANG Lin HUANG Chong LIU Gaohuan LIU Jing ZHU A-Xing state key laboratory of Resources and environment information system Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of Sciences Department of geography University of Wisconsin-Madison Jiangsu Center for Collaborative Innovation in Geographical information Resource Development and Application and School of geography Nanjing Normal University

Spatial distribution of soil salinity can be estimated based on its environmental factors because soil salinity is strongly affected and indicated by environmental factors. Different with other properties such as soil texture, soil salinity varies with short-term time. Thus, how to choose powerful environmental predictors is especially important for soil salinity. This paper presents a similarity-based prediction approach to map soil salinity and detects powerful environmental predictors for the Huanghe(Yellow) River Delta area in China. The similarity-based approach predicts the soil salinities of unsampled locations based on the environmental similarity between unsampled and sampled locations. A dataset of 92 points with salt data at depth of 30–40 cm was divided into two subsets for prediction and validation. Topographical parameters, soil textures, distances to irrigation channels and to the coastline, land surface temperature from Moderate Resolution Imaging Spectroradiometer(MODIS), Normalized Difference Vegetation Indices(NDVIs) and land surface reflectance data from Landsat Thematic Mapper(TM) imagery were generated. The similarity-based prediction approach was applied on several combinations of different environmental factors. Based on three evaluation indices including the correlation coefficient(CC) between observed and predicted values, the mean absolute error and the root mean squared error we found that elevation, distance to irrigation channels, soil texture, night land surface temperature, NDVI, and land surface reflectance Band 5 are the optimal combination for mapping soil salinity at the 30–40 cm depth in the study area(with a CC value of 0.69 and a root mean squared error value of 0.38). Our results indicated that the similarity-based prediction approach could be a vital alternative to other methods for mapping soil salinity, especially for area with limited observation data and could be used to monitor soil salinity distributions in the future.

关键词： soil salinization similarity-based prediction approach digital soil mapping Huanghe (Yellow) River Delta environmental factor

THE METHOD BASE OF GEOGRAPHIC ANALYSIS AND ITS APPLICATION

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Chinese Geographical Science 1994年第3期4卷 268-276页

作者：曹桂发 state key laboratory of Resources and environmental information system Institute of Geography the Chinese Academy of Sciences Beijing PRC

The geographical analysis method base is a software system in common use which designed by the software technology. It includes the general analysis method on optimization problems and on mathematical programming by both geographers and planners. This paper describes the method 'base and its applications. Supported by the regional information system, analysis are carried out concerning the land efficiency system, the relevance between human being and land, the effect of Beijing and Tianjin to region or the center city expansion analysis, the population forecast of Beting, the reasonable analysis of each city industry structure, and the retio degrees of regional industry distribution. The analysis results provide reliable bases for the regional development, the regional land value confirmation and the acknowledge of environment changes caused by the human action and the changes of natural items.

关键词： Method Base Geographical Application

Mapping Detailed Soil Property Using Small Scale Soil Type Maps and Sparse Typical Samples

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Chinese Geographical Science 2013年第6期23卷 680-691页

作者： ZHANG Shujie ZHU Axing LIU Wenliang LIU Jing YANG Lin state key laboratory of Resources and environment information system Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences Department of geography University of Wisconsin institute of Remote Sensing and Digital Earth Chinese Academy of Sciences

Soil type maps at the scale of I Z 1 000 000 are used extensively to provide soil spatial distribution information for soil erosion assessment and watershed management models in China. However, the soil property maps produced through conventional direct linking method usually suffer low accuracy as well as the lack of spatial details within a soil type polygon. This paper presents an effective method to produce detailed soil property map based on representative samples which were extracted from each polygon on the 1 ： 1 000 000 soil type map. The representative sample of each polygon is defined as the location that can represent the largest area within the polygon. The representativeness of a candidate sample is determined by calculating the soil-forming environment condition similarities between the sample and other locations. Once the representative sample of each polygon has been chosen, the property values of the existing typical samples are assigned to the corresponding representative samples with the same soil type. Finally, based on these representative samples, the detailed soil property map could be produced by using existing digital soil mapping methods. The case study in XuanCheng City, Anhui Province of China, demonstrated the proposed method could produce soil property map at a higher level of spatial details and accuracy： 1） The soil organic matter （SOM） map produced based on the representative samples can not only depict the detailed spatial distribution of SOM within a soil type polygon but also largely reduce the abrupt change of soil property at the boundaries of two adjacent polygons. 2） The Root Mean Squared Error （RMSE） of the SOM map based on the representative samples is 1.61, and it is 1.37 for the SOM map produced by using conventional direct linking method. Therefore, the proposed method is an effective approach to produce spatial detailed soil property map with higher accuracy for environment simulation models.

关键词： soil type map existing typical sample representative sample detailed soil property map digital soil mapping

Multi-Objective Optimization for China's Power Carbon Emission Reduction by 2035

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Journal of Thermal Science 2019年第2期28卷 184-194页

作者： WU Jianjun TANG Guihua WANG Run SUN Yanwei key lab of Urban environment and Health Institute of Urban Environment Chinese Academy of Sciences University of Chinese Academy of Sciences MOE key laboratory of Thermo-Fluid Science and Engineering Xi'an Jiaotong University Hubei University geography & Spatial information Techniques Department of Ningbo University

Low carbon transformation plays an important role in promoting the energy production and consumption revolution. Currently, the power sector of China still faces a series of challenges, such as the overcapacity of coal-fired power, the renewable energy consumption, the new constraints of carbon-emissions, and fragmented power planning. This study develops a multi-objective optimization model to predict the future trend of China power structure by 2035. The key factors such as network, power, load and storage are taken into account. Besides, the technical feasibility, economic rationality and social acceptable constraints are also fully considered. Through planning and optimization, the premise of low carbon transformation is to ensure the continuity of existing policies for removing inefficient assets, and the core is to develop and utilize non-fossil energy on a large scale. Specifically, the capacity of coal-fired power will be attained in the peak in 2025, and the factor will also transfer from main power supplier to main power and energy supplier. Before 2025, the clean replacement of incremental power installation will be completed. In 2035, 92% of new investment comes from non-fossil energy. The economy and competitiveness of wind power and PV(Photovoltaic) power generation are continuously increasing. By 2020, the coal-fired power and the wind power in eastern of China will be parity firstly. In 2025, the cost of PV and wind power will be the same. Furthermore, the evaluation dimension of modern power system with clean, low-carbon, safety and high efficiency are innovatively constructed, and the index system target of 2035 is quantitatively analyzed and prospected.

关键词： power sector carbon emission reduction optimization energy outlook comprehensive evaluation

Enhanced dominance of soil moisture stress on vegetation growth in Eurasian drylands

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National Science Review 2023年第8期10卷 135-147页

作者： Yu Zhang Yangjian Zhang Xu Lian Zhoutao Zheng Guang Zhao Tao Zhang Minjie Xu Ke Huang Ning Chen Ji Li Shilong Piao key laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences College of Resources and environment University of Chinese Academy of Sciences Sino-French institute for Earth system Science College of Urban and Environmental Sciences Peking University Department of Earth and environmental Engineering Columbia University College of Agronomy Shenyang Agricultural University Department of Geosciences and Natural Resource Management University of Copenhagen key laboratory of Wetland Ecology and environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Department of geography School of Geography and Information EngineeringChina University of Geosciences 9. State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment Institute of Tibetan Plateau ResearchChinese Academy of Sciences

Despite the mounting attention being paid to vegetation growth and their driving forces for water-limited ecosystems, the relative contributions of atmospheric and soil moisture dryness stress on vegetation growth are an ongoing debate. Here we comprehensively compare the impacts of high vapor pressure deficit(VPD) and low soil water content(SWC) on vegetation growth in Eurasian drylands during 1982–*** analysis indicates a gradual decoupling between atmospheric dryness and soil dryness over this period,as the former has expanded faster than the latter. Moreover, the VPD–SWC relation and VPD–greenness relation are both non-linear, while the SWC–greenness relation is near-linear. The loosened coupling between VPD and SWC, the non-linear correlations among VPD–SWC-greenness and the expanded area extent in which SWC acts as the dominant stress factor all provide compelling evidence that SWC is a more influential stressor than VPD on vegetation growth in Eurasian drylands. In addition, a set of 11 Earth system models projected a continuously growing constraint of SWC stress on vegetation growth towards 2100. Our results are vital to dryland ecosystems management and drought mitigation in Eurasia.

关键词： soil water content vapor pressure deficit vegetation growth decoupling non-linear relation

Spatial pattern of land cover change in China's semiarid environment

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Journal of Arid Land 2009年第1期1卷 16-25页

作者： BaoLin LI1 and QiMing ZHOU2 1 state key laboratory of environment and Resources information system, institute of Geographical Sciences and Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 Department of geography, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China state key laboratory of environment and Resources information system Institute of Geographical Sciences and Resources Research Chinese Academy of Sciences Beijing 100101 China Department of geography Hong Kong Baptist University Kowloon Tong Hong Kong

This study seeks a routine to quantify spatial pattern of land cover changes in semiarid environment of China based on post-classification comparison method. The method consists of three major steps: (1) the image classification and unification of classified results based on two-level land cover classification themes, (2) the establishment of land cover change classes based on an unification land cover classification theme, (3) the reclassification and mapping of land cover change classes with three overall classes including no-change, gain and loss based on the unification land cover class. This method was applied to detect the spatial pattern of land cover changes in Yinchuan Plain, one of famous irrigation agricultural zones of the Yellow River, China. The results showed the land cover had undergone a remarkable change from 1991 to 2002 in the study area (the changed area was over 30%). Rapid increase of cropland (12.5%), built-up area (131.4%) and rapid decrease of bare ground (51.7%) were alarming. The spatial pattern of land cover changes showed clear regional difference in the study area and was clearly related to human activities or natural factors. Thus, it obtained a better understanding of the human impact on the fragile ecosystem of China’s semiarid environment.

关键词： change detection spatial pattern land cover semiarid zone of China remote sensing human activities

Seasonal characteristics and provenance of organic aerosols in the urban atmosphere of Liaocheng in the North China Plain:Significant effect of biomass burning

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Particuology 2023年第4期75卷 185-198页

作者： Yuanyuan Li Min Chen Yachen Wang Tonglin Huang Gehui Wang Zheng Li Jianjun Li jingjing Meng Zhanfang Hou School of geography and the environment Liaocheng UniversityLiaocheng252000China key lab of Geographic information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai200241 China state key laboratory of Loess and Quaternary Geology Key Laboratory of Aerosol Chemistry and PhysicsInstitute of Earth EnvironmentChinese Academy of SciencesXi'an710075China

To better understand the seasonal characteristics of urban organic aerosol(OA)in the North China Plain(NCP),PM2.5 samples in the urban atmosphere of Liaocheng were collected and *** molecular distribution of the organic markers in the urban atmosphere of Liaocheng reveals that n-alkanes(39.3%)was the most abundant species all year round,followed by saccharides(28.2%),phthalic acids(Ph,20.8%),biogenic secondary organic aerosol(BSOA)tracers(9.4%),and polycyclic aromatic hydrocarbon(PAHs,2.3%).PM2.5,organic carbon(OC),elemental carbon(EC),and primary organic markers exhibit the highest concentrations in winter,due largely to the increased biomass burning and coal combustion for house heating in local and surrounding ***,the concentration and relative abundance of BSOA are significantly higher in summer than other seasons,induced by the more favorable meteoro-logical conditions that would promote the emissions of biogenic volatile organic compounds(BVOCs)and the secondary production of *** ratios of OC/EC and 3-methyl-1,2,3-butanetricarboxylic acid to cis-pinic acid plus cis-pinonic acid(MBTCA/(PA+PNA)are higher in the warm seasons than those in the cold seasons,indicating that the oxidation of OA is sensitive to air *** to 2017,the concentration level of PAHs during wintertime decreased by 40.8%,confirming that the stringent regulation of coal burning is *** highest concentration of high molecular weight(HMW)n-alkanes and three anhydrosugars in winter,and the close correlation of levoglucosan with HMW n-al-kanes suggests that the impact of biomass burning was more significant in *** same seasonal characteristic of the ratios of high-/low-NO_(x) products with NO_(x) and the strong correlation of high-/low-NO_(x) products with levoglucosan indicate that the formation of isoprene SOA(SOA1)tracers was signif-icantly influenced by anthropogenic *** molecular compositions,the distributions of fire spots,ba

关键词： Organic aerosol(OA)markers Seasonal variations Pollution periods Biomass burning The north China Plain(NCP)