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Science China(Information sciences) 2010年第11期53卷 2185-2194页

作者： LIU Liu1, ZHANG LiQiang1, MA JingTao2. ZHANG Liang3, ZHANG XingMing1, XIAO ZhiQiang1 & YANG Ling1 1state key {2. of {2. sensing Science, Jointly Sponsored by beijing Normal University and the institute of remote sensing applications of chinese academy of sciences, beijing 100875, China 2.TV America, Inc. 1145 Broadway Plaza Ste 605, Tacoma, WA 98407, USA 3School of Geomatics and Urban Information, beijing University of Civil Engineering and Architecture, beijing 100044, China 1. state key {2. of {2. sensing Science Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing 100875 China2. PTV America Inc. 1145 Broadway Plaza Ste 605 Tacoma WA 98407 USA3. School of Geomatics and Urban Information Beijing University of Civil Engineering and Architecture Beijing 100044 China

This paper presents an efficient method for implementing visibility analysis on complex landscapes based on an improved LOS (line of sight) algorithm. The method determines the viewshed by analyzing the geometric relationship between the target points and viewpoint. It differentiates the visibility of the target points by the elevation information. Eventually the visual results related to the given viewpoint are rendered on three-dimensional landscapes. The visibility of some target points is computed by comparing their elevations with the viewpoint's height, thus is able to enhance the efficiency of the visibility analysis. This method can not only be applied in the visibility analysis of forest scenes, but also used in the analysis of the urban environment. Experiments show that the proposed method results in high efficiency and precision.

关键词： line of sight visibility analysis complex landscapes visual permeability

Development of distributed time-variant gain model for nonlinear hydrological systems

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Science China Earth sciences 2005年第6期48卷 713-723页

作者： XIA Jun1, 2. WANG Gangsheng1, TAN Ge1, YE Aizhong2.& G. H. Huang3 1. key laboratory of Water Cycle & Related Land Surface Processes, {2. of Geographic {2. and Natural Resources Research, chinese academy of sciences, beijing 100101, China 2. state key laboratory of Water Resources & Hydropower Engineering {2., Wuhan University, Wuhan 430072. China 3. Faculty of Engineering, University of Regina, 3737 Wascana Parkway, Regina, Sask., S4S 0A2. Canada Correspondence should be addressed to Xia Jun 1. key laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. state key {2. of Water Resources & Hydropower Engineering {2. Wuhan University 430072 Wuhan China 3. Faculty of Engineering University of Regina 3737 Wascana Parkway S4S 0A2 Sask Regina Canada

In this paper, a rainfall-runoff modeling system is developed based on a nonlinear Volterra functional series and a hydrological conceptual modeling approach. Two models, i.e. the time-variant gain model (TVGM) and the distributed time-variant gain model (DTVGM) that are built on the platform of Digital Elevation Model (DEM), remote sensing (RS) and Unit Hydro-logical Process were proposed. The developed DTVGM model was applied to two cases in the Heihe River Basin that is located in the arid and semiarid region of northwestern China and the Chaobai River basin located in the semihumid region of northern China. The results indicate that, in addition to the classic dynamic differential approach to describe nonlinear processes in hy-drological systems, it is possible to study such complex processes through the proposed sys-tematic approach to identify prominent hydrological relations. The DTVGM, coupling the advan-tages of both nonlinear and distributed hydrological models, can simulate variant hydrological processes under different environment conditions. Satisfactory results were obtained in fore-casting the time-space variations of hydrological processes and the relationships between land use/cover change and surface runoff variation.

关键词： hydrological process, nonlinearity, time-variant gain model, distributed hydrological model.

A new approach toward object-based change detection

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Science China(Technological sciences) 2010年第S1期53卷 105-110页

作者： ZHANG Guo1,2.LI Yang1 & LI ZhiJiang3 1 state key {2. of Information Engineering in Surveying,Mapping and {2. sensing,Wuhan University,Wuhan 430079,China 2.Satellite of Surveying and Mapping Application center,state Bureau of Surveying and Mapping,beijing 100830,China 3 School of Printing and Packaging,Wuhan University,Wuhan 430079,China Wuhan Univ State Key Lab Informat Engn Surveying Mapping & R Wuhan 430079 Peoples R China state Bur Surveying & Mapping Satellite Surveying & Mapping Applicat Ctr Beijing 100830 Peoples R China Wuhan Univ Sch Printing & Packaging Wuhan 430079 Peoples R China

Object-based change detection has been the hotspot in remote sensing image processing.A new approach toward object-based change detection is *** two different temporal images are unitedly segmented using the mean shift procedure to obtain corresponding *** change detection is implemented based on the integration of corresponding objects’ intensity and texture *** are conducted on both panchromatic images and multispectral images and the results show that the integrated measure is robust with respect to illumination changes and *** color detection is conducted to determine whether the color of the unchanged objects changes or not when dealing with multispectral *** verification work is carried out to show the accuracy of the proposed approach.

关键词： mean shift united segmentation change detection object-based intensity texture integration

Estimation of forest volumes by integrating Landsat TM imagery and forest inventory data

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Science China(Technological sciences) 2006年第z1期49卷 54-62页

作者： GU Huiyan, DAI Limin, WU Gang, XU Dong, WANG Shunzhong &WANG Hui institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, China School of Forestry, Northeast Forestry University, Harbin 150040, China {2. key Lab of Systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, China Graduate University of chinese academy of sciences, beijing 100039, China 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China 2. School of Forestry Northeast Forestry University Harbin 150040 China 3. state key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China 4. Graduate University of chinese academy of sciences Beijing 100039 China

Accurate information about forest volumes is essential for forest management planning. The survey interval of the Forest Resource Inventory of China (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was44.2., much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%,respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.

关键词： forest inventory, landsat TM, k-nearest neighbors, spectral extraction.

Regularizing kernel-based BRDF model inversion method for ill-posed land surface parameter retrieval using smoothness constraint

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Regularizing kernel-based BRDF model inversion method for il...

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

中国科学院地质与地球物理研究所2.08学术年会

作者： Yanfei Wang,Changchun Yang,and Xiaowen Li 1 institute of Geology and Geophysics,chinese {2. of sciences, beijing,China. 2.state key laboratory of remote sensing Science and Research Center for remote sensing and GIS,beijing Normal University,beijing,China.

[1]In this paper,we consider the problem how to solve the kernel-based bidirectional reflectance distribution function(BRDF) models for the retrieval of land surface albedos. The above problem is an ill-posed inverse *** will employ a new regularization technique to alleviate the *** Tikhonov regularization has been discussed for BRDF model inversion,however,much study has to be done before applying it in practice(Wang et al,2.07).In this paper,we thoroughly investigate this method,and propose a discrepancy method for a posteriori choice of the regularization parameter and several options for choosing the regularizing *** proposed method can alleviate difficulties in numerical computation when the discrete kernel is badly conditioned and the number of observations is *** the proposed method can always find a set of suitable BRDF coefficients for poorly sampled *** proposed method is an improvement of the traditional least squares error algorithm in AMBRALS(Algorithm for MODIS(Moderate Resolution Imaging Spectroradiometer) Bidirectional Reflectance Anisotropies of the Land Surface),see Strahler et al.(1999),and is comparable to the regularized singular value decomposition method developed by Wang et al.(2.07).Hence the proposed method can be considered as a supplemental algorithm for the robust estimation of the land surface BRDF/*** performance is given in this paper for the widely used field-based 18 data sets among the 73 data sets(see Li et al.,2.01) and for the satellite data.

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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 {2. of Environment and Resources Information System, {2. 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 Hong Kong Baptist Univ Dept Geog Kowloon Tong Hong Kong Peoples R China chinese Acad Sci State Key Lab Environm & Resources Informat Syst Inst Geog Sci & Resources Res Beijing 100101 Peoples R China

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 2.02.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

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扬州市区京杭大运河水污染可视化模拟研究

系统仿真学报 2009年第12期21卷 3653-3657,3661页

作者：徐丙立林珲龚建华臧永强黄明祥太空与地球信息科学研究所香港中文大学中国香港中国科学院遥感应用研究所遥感科学国家重点实验室北京100101

以京杭大运河扬州市区段为研究对象,根据其水文特征选定了一维和二维水质模型。研究了如何实现污染时空分布的可视化模拟。详细讲述了可视化模拟的几个关键技术,即基本框架、河流栅格数据提取与叠加显示、水质模型的数值化处理与集成、... 详细信息

以京杭大运河扬州市区段为研究对象,根据其水文特征选定了一维和二维水质模型。研究了如何实现污染时空分布的可视化模拟。详细讲述了可视化模拟的几个关键技术,即基本框架、河流栅格数据提取与叠加显示、水质模型的数值化处理与集成、多点排污计算与颜色匹配、污染曲线绘制及多时相历史污染再现。开发河流水污染可视化模拟系统,对扬州市区京杭大运河真实数据和假设数据分别模拟,效果良好。创新点在于将地理信息和专业的水污染模型无缝集成,并将数据、模型计算和结果表达集成在统一的实时可视化平台中。

关键词：河流水污染可视化模拟

Glacier changes during the last forty years in the Tarim Interior River basin,northwest China

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Progress in Natural Science:Materials International 2009年第6期19卷 727-732页

作者： Donghui Shangguana, Shiyin Liu a,b, Yongjian Dinga, Lianfu Dinga, Junli Xua, Li Jing a a state key {2. of Cryospheric Science, Cold & Arid Regions Environmental & Engineering Research {2., chinese academy of sciences, Lanzhou 730000, China b {2. for Tibetan Plateau Research, chinese academy of sciences, beijing 10002., China [a]state key {2. of Cryospheric Science Cold & Arid Regions Environmental & Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China [b]Institute for Tibetan Plateau Research Chinese Academy of Sciences Beijing 100029 China

By comparing digitized glacier outlines from the chinese Glacier Inventory (CGI) during the 1960s-1970s and Landsat Enhance Thematic Mapper (ETM+) images from 1999 to 2.01, we investigated changes for about 7665 alpine glaciers among 11665 glaciers in seven sub-basins of the Tarim Interior River basin (TIRB). The results showed that the total glacier area was reduced by 3.3% from the 1960s/ 1970s to 1999/2.01 and area losses for 1-5 km2.glaciers accounted for 48.3% of the total glacier area loss in the TIRB. However, the glacier area reductions varied from 0.7% to 7.9% among the seven sub-basins of the TIRB during the study period. The glacier area changing with altitude showed that the maximum contribution of area shrinkage occurred at 4900-5400 m. Data from 2. meteorological stations in the TIRB showed increases in both the annual mean air temperature and annual precipitation during 1960-2.00. This indicates that the glacier shrinkage in the TIRB over the last 40 years was largely due to regional climate warming that enhanced glacier ablation and overcame the effects of increased precipitation on the glacier mass balance.

关键词： Glacier change Climate change remote sensing

Gradient analysis of landscape spatial and temporal pattern changes in beijing metropolitan area

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Science China(Technological sciences) 2010年第S1期53卷 91-98页

作者： YANG YeTao1,ZHOU QiMing2.GONG JianYa3 & WANG YingYing4 1 institute of Geophysics and Geomatics,China University of Geosciences,Wuhan 430074,China 2.Department of Geography,Hong Kong Baptist University,Hong Kong 3 {2. key laboratory of Information Engineering in Surveying,Mapping and remote sensing,Wuhan University,Wuhan 430074,China 4 Hubei Provincial Bureau of Meteorology,Wuhan 430074,China 1. institute of Geophysics and Geomatics China University of Geosciences Wuhan 430074 China2. Department of Geography Hong Kong Baptist University Hong Kong China3. State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430074 China4. Hubei Provincial Bureau of Meteorology Wuhan 430074 China

The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the *** order to discover the trend of spatio-temporal changes in beijing metropolitan area during the past 15 years,several landscape metrics are computed using a moving window along a 96 km long transect across beijing metropolitan area from west to ***,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly *** results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.

关键词： gradient analysis landscape metrics spatio-temporal urban expansion multi-extent