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  • 2012 Volume 14 Issue 1
    Published: 25 February 2012
      
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  • ARTICLES
    Changing Characteristic of Land Surface Evapotranspiration and Soil Moisture in China during the Past 30 Years
    BING Longfei, SU Hongbo, SHAO Quanqin, LIU Jiyuan
    2012, 14(1): 1-13. https://doi.org/10.3724/SP.J.1047.2012.00001
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    The land surface evapotranspiration (ET) and soil moisture used in this paper were retrieved from land surface model (LSM) of NOAH. The variation of land surface ET and soil moisture was analyzed by statistics in six large regions and by four ecosystem types in China. Then the relationship between ET and soil moisture was discussed. The long term trend of land surface ET was increasing in China. The maximum ET occurred in July, while the minimum one was usually at the beginning/end of a year. The trend of ET in South-Central China, Southwest China, East China, Northeast China and Northwestern China was also increasing, agreed with the whole China. The long term variation trend of ET was decreasing in North China, where the maximum ET was 43.091 Billion Cubic Meters (BCM) in 1990. The relative ratio of evapotranspiration of forest was the highest among all the ecosystem types in Northeast, East, Southwest and South-Central China, while the highest one was grassland in North and Northwest China. To compare the amount of water used by evapotranspiration, the biggest forest ET was in Southwest and South Central China, the smallest was in Northwest China; the biggest grassland ET was in Southwest China, the smallest was in Northeast China; the biggest farmland ET was in East China, the smallest was in Northwest China; the biggest ET for desert and wet land was in Northwest and Northeast China respectively. The soil moisture was decreasing in most China regions except for that in Northwest China ever since 1980s, agreed with the whole China. The main impact factors of ET were vegetation fraction and soil moisture. There existed a good relationship between soil water content and evapotranspiration in rare vegetation covered regions.
  • ARTICLES
    Application Analysis of Surface Air Temperature Change Estimation Methods in Chinese Mainland
    SUN Chaoyang, SHAO Quanqin, LIU Jiyuan
    2012, 14(1): 14-21. https://doi.org/10.3724/SP.J.1047.2012.00014
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    The methods used in surface air temperature change estimation in Chinese Mainland during recent 20 years are summarized in this paper, and data materials, temporal scale and results in different researcher's study are contrastively analyzed. Based on the meteorological observation air temperature data from 1970 to 2007 and several popular warming estimation methods internationally used, we estimated the warming trend in recent 40 years. The results of direct average method, calculation by station method, regional area weighted method, first difference method and spatial interpolation method show the same warming trend in recent years and every season in Chinese Mainland, but vary in quantities clearly. The uncertainties in warming estimation with different methods are analyzed and it is concluded that the warming trend in recent 40 years ranges from 0.30-0.43℃/10a, the warming amplitude is between 1.16 and 1.56℃, warming is most apparent in winter and slightest in summer, warming in the northern part is more than in the southern part.
  • ARTICLES
    Spatio-temporal Difference of Economic Growth in the Loess Plateau Region over the Past 20 Years
    LIU Yanhua, XU Yong, LI Yi
    2012, 14(1): 22-31. https://doi.org/10.3724/SP.J.1047.2012.00022
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    Economic activities are always located unevenly in a region. Analyzing and detecting the spatio-temporal difference of economic factors, and finding out the underlying reasons would be very useful for undeveloped regions to recognize problems and then seek for a better way to deal with them. Under support of GIS, this essay analyzed the spatio-temporal characteristics of economy growth on the Loess Plateau Region over the past 20 years by using data of 284 counties' per capita GDP. And the results included: (1) The level of GDP of the Loess Plateau Region had been growing continuously and rapidly since the Reform and Opening of China. And the Western Development Strategy of China is the main reason for the rapid increase of proportion of GDP of the Loess Plateau Region in that of the whole China since 2000, while energy/resources exploring in Shanxi, Shaanxi and Inner Mongolia Region is the direct motivate cause. (2) Distribution of per capita GDP in this region showed a characteristic with two high-value strips and one low-value strip, with economic polarization force reshaping it gradually. Energy/resources exploring, agricultural density, population distribution and natural base are the key factors affecting the spatial distribution and evolution of per capita GDP in the Loess Plateau Region. (3) The growth of per capita GDP in the region showed a polarizing increase character, and with it is the adjustment of position of economic growth poles. There are two kinds of polarizing growth in the Loess Plateau Region. One is the normal economic growth pushed by industrial agglomeration, and the other is the opportunistic economic growth pulled by energy/resources exploring. To be noticed, the latter force is far more powerful in promoting the level of per capita GDP, but always with problems of singleness of industry type and lack of stability, sustainability and interference immunity during its working process in pulling economic growth. And (4) according to the conclusions, it is suggested that the Loess Plateau Region should take good advantage of its opportunity in the nation's Western Development Strategy, speed up its pace to cultivate its central cities as growth cores, and build up bridges between its growth poles and energy/resources production areas. And then it could be expected to develop in a quicker, better and more sustainable way, with central cities as the main engine and energy/resources production areas as auxiliary engine to pull the whole region together for the future.
  • ARTICLES
    Analysis of Spatio-temporal Characteristics of Drought in Southwest China in 2010 by Using MODIS-based Normalized Difference Drought Index
    BAI Kaixu, LIU Chaoshun, SHI Runhe, GAO Wei
    2012, 14(1): 32-40,48. https://doi.org/10.3724/SP.J.1047.2012.00032
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    Drought has frequently brought huge damage to local agricultural production and ecological environment in China. In order to acquire large-scale land surface water information to assess drought severity quickly and accurately, normalized difference drought index (NDDI) was proposed which based on visible and near infrared band reflectance. In this paper, the spatio-temporal characteristics of drought in southwest China in 2010 was analysed using NDDI, with Yunnan, Guangxi and Guizhou provinces as the study area. Firstly, MODIS images were preprocessed and then normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were calculated with different bands data retrieved from MODIS reflectance product. Secondly, NDDI was calculated by using NDVI and NDWI. During this process, pixel reliability data acquired from MODIS product was introduced. The main purpose of this data was to eliminate noise such as clouds and ice or snow in NDDI calculation. Next, the correlation between NDDI and ground-based soil moisture was validated, also intercomparison between NDDI and vegetation condition index (VCI) was analysed. The result showed that NDDI was sensitive to ground soil moisture and demonstrated even quicker response to shallow surface drought severity than that of VCI. Finally, the spatio-temporal distribution of drought in southwest China in 2010 was reoccurred with NDDI index, and also land area with different drought severity was derived. The result showed that the period that suffered from most severe drought conditions lasted from January to April in 2010 in Guizhou Province, the maximum drought-stricken area was 132257 km2 and it occupied more than 75% of the total area of Guizhou Province. Meanwhile, the maximum area suffered from "heavy drought" was 88246 km2 and it occupied more than 50% of the total area of Guizhou Province.
  • ARTICLES
    Average Slope Length Calculation and Runoff Simulation
    YU Wenjun, NAN Zhuotong, LI Shuo, LI Chenggang
    2012, 14(1): 41-48. https://doi.org/10.3724/SP.J.1047.2012.00041
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    Watershed average slope length (ASL) is defined as the average distance measured along the main channel from the watershed outlet to the basin divide. It is an important parameter in a hydrologic model. Theoretically ASL is related to the calculation of lateral flow and routing timing, which eventually impacts simulation of the total surface runoff. SWAT (Soil and Water Assessment Tools) is a river basin scale model developed to predict the effects of management decisions on water, sediment, nutrient and pesticide yields with reasonable accuracy on lager, and ungauged river basins. The AVSWAT model, an integration of SWAT2005 and ArcView GIS 3.2, was applied in this paper to simulate monthly stream flow (1990-2009) of the Yingluoxia outlet of the 10 000 km2 upstream basin of the Heihe River basin (HRB). The simulation showed that ASLs calculated by the AVSWAT model were not consistent with the actual cases in the upstream basin of HRB. As a result, it led to an inaccurate simulation. To address this problem, a new approach has been adopted to correct ASL of each sub-basin. A regression equation, which reflects the relationship between average slope and average length, was established by measuring average slope of each sub-basin. Using the corrected slope lengths and the default parameter set of SWAT together with meteorological and hydrologic data from 1990 to 2009, Nash-Sutcliffe coefficient (NSE) of monthly runoff simulation is obviously improved to 0.75 in contrast with 0.60 with uncorrected slope lengths and same parameter set. Sensitivity analysis and an examination of CN2 parameter were also conducted to prove the applicability of this correcting method. The results showed that corrected slope lengths were more suitable for the studied mountainous basin and also verified its applicability of the adopted correction approach. Using the corrected ASLs, an error-trial optimization was used to optimize other parameters. The validation with daily runoff from 2000-2009 showed an NSE of up to 0.81, which suggested an acceptable simulation for the study basin. We concluded on basis of corrected slope lengths quite good simulation can be achieved by parameter optimization. Therefore, the approach to correct ASL is feasible in mountainous basin, and the corrected slope lengths have made the stream flow simulation better.
  • ARTICLES
    A Study on Soil Property Mapping at National Scale Based on Sparse Grid Soil Samples
    YU Wanli, LI Baolin
    2012, 14(1): 49-54. https://doi.org/10.3724/SP.J.1047.2012.00049
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    Soil property data at national scale are necessary inputs for researches on biogeochemical and hydrological cycles. There are two commonly used methods to obtain accurate soil property data at this scale including soil linkage method and spatial interpolation method. In this paper, soil organic matter (SOM) content in Jilin Province was taken as a case study to evaluate these two methods based on 8~32 km grid soil samples and 1∶1 million soil map, in order to provide suggestions about soil property mapping at national scale based on sparse grid soil samples. Independent validation indicated that the mean error (ME) of the soil linkage method was -0.58, higher than the inverse distance weighted (IDW) interpolation method (0.13), but the mean absolute error (MAE) and root mean square error (RMSE) of the soil linkage method were 1.12 and 1.76, respectively, lower than those of IDW interpolation method (1.43 and 2.12). Although the soil property map through IDW interpolation revealed the general trend of soil property distribution, it had "Bull's eye" pattern and the estimations in areas with few or no soil samples were unreliable. The soil property map obtained by soil linkage method ignored the variations inside the same soil type on the soil map and a break of soil property existed around different soil boundaries, but the soil distribution regularity was well represented in this map and the details could be obtained. According to the validation results of maps through these two methods, the soil linkage method is better than the spatial interpolation method in soil property mapping based on sparse grid soil samples at national scale.
  • ARTICLES
    Dynamic Strip Partitioning Method Oriented Parallel Computing for Construction of Delaunay Triangulation
    QI Lin, SHEN Jie, GUO Lishuai, ZHOU Tong
    2012, 14(1): 55-61. https://doi.org/10.3724/SP.J.1047.2012.00055
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    Data partitioning is an important step of parallel algorithm design. The load balance and efficiency of data partitioning is the precondition for improvement of parallel algorithm efficiency. For aggregated distributed point sets, the traditional Delaunay triangulation parallel algorithm can't ensure the balance and the execution's efficiency of the partitioning result. In view of the problems above, this paper we proposed a partitioning method using dynamic strips based on the idea of equally strips partitioning method in traditional Delaunay Triangulation construction and we titled it Dynamic Strip Partitioning Method. The detailed steps of this algorithm are as follows. First, the minimum bounding rectangle of the point data set should be obtained and the point set is roughly split using regular slim strips in the same direction. Then the number of points in every strip would be counted and the neighbor strips are merged into a partition region from the first strip in the sequence following a certain regulation. The boundaries of some strips should be moved dynamically if the total amount of points in these strips reached the load threshold value. In order to promote the efficiency of partitioning and reduce the boundaries movement, a rule of "move half points a time" has been used. We tested the speed-up of the Delaunay Triangulation parallel algorithm using the artificial point sets and tested the performance of the Delaunay triangulation parallel algorithm using the real test area point sets in the multi-kernel parallel computing systems. The results of the experiments showed that the method of dynamic strips partitioning can help to get high and stable speed-up of the Delaunay triangulation parallel algorithm and the data distributional pattern and size has less influence to it. Delaunay triangulation parallel algorithm based on dynamic strips partitioning method can get high efficiency and the speed-up effect is superior to the traditional method.
  • ARTICLES
    Uncertainty Analysis of Different DEM Interpolation Methods Based on AMMI Model
    ZHAO Mingwei, TANG Guoan, TIAN Jian
    2012, 14(1): 62-66. https://doi.org/10.3724/SP.J.1047.2012.00062
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    Analysis of evaluation of interpolation models is a hot topic in the DEM interpolation studies. Most studies focused on the interpolation model in the last decades, while ignored the influencing factors between the interpolation models and environments. That is to say, on the one side, different interpolation models influence the accuracy of the analysis result; on the other side, difference environments also influence the accuracy of a certain interpolation model. In order to analysis the applicability of different interpolation methods in different environments, this paper selected test areas under different geomorphic types, and used the AMMI model to analyse the accuracy of the different interpolation models and the applicability of the studied models to different geomorphic types. The experiment results showed that the AMMI model could test the influencing factors between the interpolation models and the environments. Taking the test of this paper as an example, in the Northern Shaanxi region, the ordinary Kriging model is the best choice in the DEM construction. Finally, by analyzing the correlation coefficient between the environment coefficient and several landform parameters, it can be found that the slope gradient could represent the first environment coefficient.
  • ARTICLES
    Spatio-Temporal Vector Data Modeling Based on Geometric Algebra
    YU Zhaoyuan, YUAN Linwang, HU Yong, LI Yu, ZONG Zhen
    2012, 14(1): 67-73. https://doi.org/10.3724/SP.J.1047.2012.00067
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    Spatio-temporal modeling is one of the most important topics in the field of GIS. Unified representation of space and time can be seen as a new potential for temporal GIS, though practical advices on it in real world are still lack. The geometric algebra linking expression and computation of elements at different dimensions provides potations to express space and time in a unified framework. This paper proposes geometric algebra to overcome the drawbacks of existing vector spatio-temporal data modeling methods in representing time and space individually, which will lead to express inconsistent and not uniform issue. Based on the coding of coordinates with geometric algebra elements, the unified spatio-temporal expression integrates the temporal and spatial parts as a whole, by linking the basic elements of geometric algebra of different grades. And then, time, space and attributes are expressed and modeled based on geometric algebra and unified spatial-temporal views. The heretical level structure of unified spatio-temporal expression is proposed and the logical relations of time, space and attributes are discussed based on the UML technology in an object-oriented way. The process flow of unified vector spatio-temporal data model was proposed. Based on the multivector structure of geometric algebra, data organization and storage structures were defined. Finally, a prototype system was implemented that integrates the above mentioned technologies. Changing data of administrative regions (at prefectural level) of southeast China was used to evaluate the method. The results suggest that the method proposed in this paper can support unified spatio-temporal modeling and expression, which can also support the construction and implementation of spatio-temporal analysis methods, e.g. change detection. It seems that our work can provide theoretical foundation and method implementation reference for the development of temporal and spatial GIS.
  • ARTICLES
    Construction of Resource and Environment Science Expedition Data Resources Integration System in Northeast Asia
    WANG Juanle, SONG Jia, ZHU Lijun
    2012, 14(1): 74-80. https://doi.org/10.3724/SP.J.1047.2012.00074
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    Northeast Asia is a key area for Earth system study, global change frontier science research and regional sustainable development research, where has complex ecological environment pattern, variety of climate zones, and typical human-earth relationship comparing characteristics. Large amount of scientific expedition data are accumulated in the past several years in Northeast Asia (here refers to Northern China, Mongolia, and Siberia and Far East area of Russia) under the cooperation of China, Mongolia and Russia scientists. These data have multi-disciplinary features. How to integrate these scientific expedition data public services is a problem. According to these scientific expedition data accumulation and management requirements, we designed a data resources integration system, which has 3 sub systems, i.e., data resources collect and management standards and specifications system, data classification system, data management and publication software platform. Data resources collection and management standard and specification system has 23 specifications, which can be divided into 3 types, i.e., data collection and processing specification type, data analysis and archiving specification, and data management and sharing specification. Data resources classification system has 4 classes, 25 sub classes and 128 data elements. Data management and publication software platform has 5 function models, i.e., data catalogue search model, metadata management model, data publication and virtualization model, data view model and data download model. Based on the designed data integration system, a prototype system has been developed supported by computer technology and Web GIS technology. As far 144 datasets have been integrated in this data system. With more and more data are accumulated and integrated in this system, it will play an important role for the scientific expedition data application and analysis in the near future.
  • ARTICLES
    Data Integration of Ichnography and Profile in Field Archaeology
    YANG Lin, SHENG Yehua, PEI Anping
    2012, 14(1): 81-84. https://doi.org/10.3724/SP.J.1047.2012.00081
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    Traditional field archaeology in China is based on manual method and the main field data are delaminated ichnography and profile map of stratum and relic. Based on the original ichnography and profile data, the character of the current record method had been analyzed and the demand of data integration in field archaeology for rapid mapping and field scene 3D reconstruction had been summarized in this paper. With the object-oriented approach, we had studied the integration rules of spatial data in field archaeology, designed and completed the united coordinate datum of the original ichnography and profile maps (the keystone was transforming the 2D data to 3D one in a united coordinate system based on delaminated ichnography and profile map of stratum and relic and distributing map of rectangular units), the stitching of stratum profiles and integrated ichnography from delaminated ones based on GIS. Moreover, we had put forward an integration method of ichnography and profile data, with the stratum profiles integrated to a stitching map (the key point was constituting uniform rules for pinch-out of stratum lacunae based on the topological relation and the attribute information of the stratum) and delaminated ichnographies of rectangular unit piled up to an integrated ichnography (the key question was the integration regulation and methods based on the archaeological criterion and he spatial relations of the archaeological objects in a site and complement by GIS software), and ichnography and profile of relic integrated to a stitching map of integrated ichnography of relic. Finally, the real excavation map data, i.e. Bashidang Site, Li County of Hunan Province were used to test the above proposed method. Through comparing with the original manual integrating map the results showed that the method in this paper provided a valid and precisely faithful way for rapid mapping, archaeological report, and basic data for cultural site scene 3D reconstruction and proved to be an assistant decision tool for analyzing and studying the spatio-temporal relation of the accumulation and the vestiges in field archaeology.
  • ARTICLES
    Measuring City Centralities Based on the Train Network of China
    ZHONG Ke, XIAO Yu, XU Jun, MA Fuguang, LIU Yu, WU Lun
    2012, 14(1): 85-93. https://doi.org/10.3724/SP.J.1047.2012.00085
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    Using centrality measures, in this research we analyzed the cities statuses in China's railway network. First, according to the L space model we built the railway network based on a train schedule. Second, different centrality measures, including degree centrality, closeness centrality and betweenness centrality, were adopted to evaluate the cities in the railway network. Finally, we investigated the patterns of different centrality measures in the network to reveal the relationship between the structure of train network and urban development.
  • ARTICLES
    Research on Sky View Factor in Urban Area Based on Urban Digital Elevation Model:A Case Study of Nanjing Old City
    HE Wenhui, YANG Xin, TANG Guoan, ZHOU Yi
    2012, 14(1): 94-100. https://doi.org/10.3724/SP.J.1047.2012.00094
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    The sky view factor (SVF) has been commonly used to describe the shadow impaction of visualization or sunshine from neighborhood buildings or terrains in urban area. It reflects the influences of urban geometry on the microclimate in an urban area. Firstly, we provided a comprehensive review of SVF analysis both in natural terrain and urban area studies. Then we presented a simulation approach based on shadow casting algorithm to calculate continuous SVF values. And, using raster-based data model we analysed the effect of sun shadow shading by neighbor buildings, simulated solar radiation for many times by continuing translation of the solar altitude and azimuth and calculated whether cells were in shadow. The ratio of simulation times and the times of a cell in shadow is considered as an approximate value of SVF. An ArcGIS-embedded computer program is developed and a SVF map for entire area is generated by using high resolution urban digital elevation model of Nanjing old city. Some areas representing different land use types in Nanjing old city are selected for analysis of the small-scale spatial variation of the SVF. The result illustrates that SVF decreases as building height raises or building quantity increases. Mean, maximum, minimum and standard deviation of SVF for each land use category within Nanjing old city are calculated and they are significantly different in different areas. The mean SVF values occurring in parks, open space and areas of historical and cultural value are higher than those of other land use types, which are more than 0.8. The mean SVF values occurring in community centers and residential areas are lower than those of other land use types, which are lower than 0.6. One of the most noticeable results is the unexpectedly higher mean SVF value in commercial areas than that in residential area in Nanjing old city. Meanwhile, spatial distribution pattern of SVF is derived by regarding block as a basic statistical unit. The mean values in the city centre are high while that in urban fringe are usually low. The blocks with high values line up in a northwest to southeast alignment, which may have an effect on urban microclimate.
  • ARTICLES
    A Wavelet Auto-focusing Method of the Aerial Camera Based on CCD Mosaicing
    LI Shanshan, GONG Huili, LIU Yang, HU Zhuowei
    2012, 14(1): 101-108,122. https://doi.org/10.3724/SP.J.1047.2012.00101
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    A wavelet auto-focusing method is proposed to consider the characteristic of the aerial camera CCD mosaicing structure. In order to evaluate the clarity of the image obtained by the aerial camera, an image assessing function is constructed based on the wavelet transform. The evaluation function is constructed by the wavelet coefficients of the image, and the characteristic of the CCD mosaicing structure was taken use to solve the problem that the evaluating values can't be compared for the variable images. On the basis of the wavelet evaluating function, the quality of the image was assessed. Then the CCD mosaicing structure was utilized to perform auto-focusing process, and a simulation was made to validate the novel method in the end. The weights are set according to the characteristic of the human vision system (HVS). In order to make the function adaptive to different images, the properties of the wavelet basis are analyzed. At the same time, the area with high frequency component is chosen as the evaluating area so as to improve the sensitivity of the evaluating function. And the flow chart of the focusing based on this method is described particularly. There are some innovation in this paper, such as: the weights of the wavelet coefficients in the evaluating function were set according to the characteristic of the wavelet transform and HVS, which is close to human subjective feel and insensitive to noise|the properties of the wavelet basis were analyzed so as to make the function adaptive to images with different high-frequency components|the wavelet basis with the best effect is symlet2 and the level of decomposing is three|the problem that auto-focusing of the aerial camera can't use digital images processing directly was solved by making use of the CCD mosaicing structure. All in all, this paper introduces a wavelet auto-focusing method based on digital image processing to aerial camera used the characteristic of CCD mosaicing structure. The function is close to the HVS subjective feeling and adaptive to objects with different frequency components, and this method is more sensitive and adaptive than traditional wavelet methods. It could obtain high image quality, and is suitable to the application in focusing system of the aerial camera.
  • ARTICLES
    Research of Remote Sensing Pyramid Texture Compression in Network
    LI Yanhong, PANG Xiaoping, LI Haiting
    2012, 14(1): 109-115. https://doi.org/10.3724/SP.J.1047.2012.00109
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    To establish the pyramid model of remote sensing data with different resolution is the main means in Virtual Earth platform's construction, and the efficient compression of remote sensing data is the basis of the model application. To search for an efficient image compression method the paper analyzed a variety of image compression methods and proposed to use JPEG2000 compression standard which based on wavelet transform as the image tile's compression method. This paper introduced the basic framework and algorithm features of wavelet-based JPEG2000 standard, and it realized the compression and decompression process of image tiles based on JJ2000 software under the network environment, and it implemented a five-grade discrete wavelet transformation on four remote sensing mages. The paper did series of experiments on consumption time of the image compression and the image reconstruction under different block sizes and different compression ratios. The block sizes included 1024×1024, 512×512, 256×256, 128×128, 64×64, and 1∶15, 1∶30, 1∶60 were involved in the compression ratios, and it gave a performance comparison by changing the block size and the compression ratio. Finally, the article took the peak signal to noise ratio (PSNR) as the objective evaluation criteria of image compression quality and used standard PSNR with different compression methods to conduct an objective evaluation and a performance comparison of image quality, and the compression methods included JPEG2000, DXT and JPEG. The results indicated that JPEG2000 can maintain high quality with high compression ratio and has many good characteristics, such as progressive transmission, random access stream, region of interest encoding and good capabilities of error-resilience. This study is helpful in providing a more efficient image compression method for the pyramid model application.
  • ARTICLES
    Design and Development of City Application Service Platform for Multi-source Remote Sensing Images
    ZHONG Jiusheng, JIANG Nan, HU Bin, WANG Junshu
    2012, 14(1): 116-122. https://doi.org/10.3724/SP.J.1047.2012.00116
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    The management and sharing of multi-source remote sensing images is very important for full using of image data, however, the traditional management modes sometimes appear passive effects in practice, owing to the lack of techniques. In this paper, we presented and discussed the system goals, the system flow, four function modules and four key technologies. Through analyzing the data source, existing management mode and business processes of remote sensing images, we designed a logical organization model of multi-source remote sensing images, and then established a massive remote sensing image database. Then we discussed the four function modules in detail and analysis the four key technologies. The four function modules are image pre-processing, image management, security control and image applications and services. And the key technologies are the system architecture on the basis of plug-in module and messages broadcast mechanism, automatic extracting meta-data, quick searching for images and efficiently online application services. The system uses Client/Server and Browser/Server mixed architecture, which is developed in the local area network to ensure a highly safe reliable and real-time environment. The result shows, comparing with traditional methods, this study achieves a unified and efficient management, quick searching, efficient browsing of massive multi-source remote sensing images and seamless integration with other subsystems, which provides convenient image data services for city application and helps to make further use of remote sensing images.
  • ARTICLES
    Analysis on the Fading Alteration in Bashibulake Uranium Mineralization Area Using Quickbird High Resolution Satellite Remote Sensing Data
    YE Fawang, LIU Dechang
    2012, 14(1): 123-127. https://doi.org/10.3724/SP.J.1047.2012.00123
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    Bashibulake uranium deposit, which located in the northwest fringe of Tarim basin in Xinjiang Uygur Autonomous Region, was considered to be closely related with oil-reduced fading alteration. However, the evidences about the oil-reduced fading alteration genesis mainly came from the geological and geochemical microscopic researches. In this paper, the enhancement processing of Quickbird high spatial resolution satellite remote sensing data was firstly made on the basis of analyzing the geological characteristics of uranium mineralizing fading alteration sandstone and the band feature of Quickbird data. Through above processing, the ability of Quickbird images to interpret the fading alteration sandstone was further promoted. Secondly, the features about shape, spatial distribution for oil-reduced fading alteration sandstone which exposed on the Bashibulake uranium ore area were analyzed using the enhanced Quickbird images. Analysis included the following three aspects. One was the general distribution for the fading alteration sandstone from the wide scale of the uranium ore area and its around area. The second was the shape feature and spatial distribution characteristics for the purple red sandstone, which was not under subjected of fading alteration, from the scale of the whole uranium mineralization district. The third was the shape and spatial expand feature for the grey yellow fading alteration sandstone that is located in the internal of a large unfading purple red sandstone from the more large scale of the east uranium ore area. Above results provided the macroscopic evidence from both positive and negative aspects to verify the uranium mineralizing fading sandstone was generated by the oil-reduced alteration, rather than the original sediment genesis. In the same time, the idea about whole spatial distribution of the fading alteration sandstone can provide important information for uranium prospect in the outer edge of Bashibulake uranium mineralization area. All above researches fully show the great application potential for Quickbird high spatial resolution satellite remote sensing data on uranium mineralization exploration.
  • ARTICLES
    GDP Spatialization in China Based on Nighttime Imagery
    HAN Xiangdi, ZHOU Yi, WANG Shixin, LIU Rui, YAO Yao
    2012, 14(1): 128-136. https://doi.org/10.3724/SP.J.1047.2012.00128
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    Resources and environmental sciences require greatly the spatialized socio-economic data sets which are always obtained from administrative regions at national or provincial level, and accurate estimates of the magnitude and spatial distribution of economic activity have many useful applications. Developing alternative methods for making estimates of gross domestic product (GDP) may prove to be useful when other measures are of suspect accuracy or unavailable. Based on the summary and analysis of existing economic activity spatialization approaches and nighttime imagery applications in economic activity, this research explores the potential for estimating the GDP using relationship between the spatial patterns of nighttime satellite imagery and GDP in China by correlation analysis and regression analysis using concerned data processing software. With the regional differences of China's economic development, logarithmic regression models have been established between different night light indexes and GDP, primary industry, secondary industry, tertiary industry and the sum of secondary industry and tertiary industry at the provincial level. A clear logarithmic linear relationship between nightlight imagery and GDP, especially the correlation coefficient of night light index and the sum of secondary industry and tertiary industry is 0.824 and R2 of them is 0.679 at national level, suggests that this method is available and feasible to estimate the spatial distribution of economic activity such as GDP. The result, 1-km grid GDP map of China based on nighttime light data, by comparing with the other GDP spatialization approaches, shows the obvious advantage to reflect complete details and characteristics of the national secondary industry and tertiary industry distribution, which is extending the field of nighttime light data research and applications for the socio-economic data in resources and environmental sciences.
  • ARTICLES
    Study on Landscape Stability in Guansihe Watershed
    LIU Yanguo, WANG Qing, WANG Jun
    2012, 14(1): 137-142. https://doi.org/10.3724/SP.J.1047.2012.00137
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    TM remote sensing data of Guansihe watershed in the two periods of 1995 and 2005 was taken as the basic information source, and vector data of landscape types was extracted with the RS, GIS and mathematical statistics methods. Three indices such as matrix proportion, change rate of patch number and area, change rate of patch density as well as transform rule of Landscape types were used for landscape stability study of the watershed. The results showed that: (1)In the whole watershed, cultivated land was matrix of the artificial landscape which was in frequent farming and dynamic change, the stability was not high; Pinus massioniana woodland was matrix of the semi-natural landscape whose stability was also low but had improved; (2) Patch stability of town and water areas were the highest, Pinus massioniana woodland, Quercus aliena woodland and Cupressus funebrius woodland took the second place, cultivated land and villages were the lowest; (3) Dramatic transformation of cultivated land, water areas and woodlands were the most, which was closely related to the land conversion projects implemented in the watershed since 1998. When cultivated land areas decreased, water areas and woodlands would increase gradually. As a result, the ecosystem and biodiversity would increase, function of the ecology would improve respectively, and the landscape pattern presented good development tendency, but the stability of water areas and woodlands still depended on its natural stability; And (4) stability of medium and small patches of Pinus massionian woodland and Cupressus funebrius woodland played an important role in the stability of the watershed. They should be protected, planed and constructed scientifically and reasonably.