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    A MODIS data derived spatial distribution of high-, medium- and low-yield cropland in China
    Yongzan JI, Huimin YAN, Jiyuan LIU, Wenhui KUANG, Yunfeng HU
    Acta Geographica Sinica    2015, 70 (5): 766-778.   doi: 10.11821/dlxb201505008
    Abstract2681)   HTML88)    PDF (2930KB)(302584)      

    With the population increase and food consumption upgrade in China, the issue of food self-sufficiency attracts much attention from both Chinese government and international society. Under the circumstances of inadequate cropland resources supply and plenty of cropland occupied by urban construction, improving the utilization efficiency of arable land resources and increasing the cropland productivity have become the fundamental strategies of agricultural development in China. Since 1988, cropland improvement projects (medium-yield and low-yield field improvement and high-standard cropland construction) have been launched and implemented on a large scale, therefore a spatially explicit map for the distribution of high-, medium- and low-yield cropland was essential for cropland improvement planning. In this study, a new method for recognizing high-, medium- and low-yield field is developed based on cropland productivity, which is calculated by using a light use efficiency model and MODIS data with a 500-m resolution. This method can not only reflect the regional heterogeneity of cropland condition, but also express the spatial differences on a grid scale. At the same time, it effectively overcomes the shortage of statistical data based method in a county unit. The results show that the proportion of high-yield, medium-yield and low-yield cropland in China is 20.66%, 39.56% and 39.78%, respectively. About 3/4 of low-yield cropland is located in the hilly and mountainous regions, while 53% of the high-yield cropland is located in plain area. The five provinces with the largest area of high-yield cropland are Henan, Shandong, Jiangsu, Hebei and Anhui, which are all located in the Huang-Huai-Hai region. The sum of the high-yield cropland area in these five provinces accounts for 41.75% of the national total high-yield cropland area. In Heilongjiang province, Sichuan province and Inner Mongolia autonomous region, where the cropland area ranks the top three of China, the proportion of high-yield cropland area in each province only accounts for not more than 15%.

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    Assessment of protection effectiveness of nature reserves on the Tibetan Plateau based on net primary production and the large-sample-comparison method
    Yili ZHANG, Zhongjun HU, Wei QI, Xue WU, Wanqi BAI, Lanhui LI, Mingjun DING, Linshan LIU, Zhaofeng WANG, Du ZHENG
    Acta Geographica Sinica    2015, 70 (7): 1027-1040.   doi: 10.11821/dlxb201507001
    Abstract1250)   HTML30)    PDF (10955KB)(151978)      

    A total of 21 typical coupled large samples were chosen from areas in the nature reserves and their surroundings on the Tibetan Plateau (TP) with large-sample-comparison method (LSCM). To evaluate the protection effectiveness of the nature reserves, we compared the alpine grassland net primary production (NPP) of these coupled samples and analyzed the differences between them before and after their establishment as protected areas. The results show that: (1) In view of alpine grassland NPP, the ecological and environmental conditions of most nature reserves were more fragile than those of their surrounding areas and also lower than the average values for the TP. (2) Of the 11 typical nature reserves selected, the positive trend of NPP in Manzetang is the most significant, while in Taxkorgan, the trend is not obvious. Moreover, with the exception of Selincuo, the annual NPP growth rate in nature reserves covered by meadow and herbaceous wetland is higher than that in nature reserves consisting of steppe and desert grassland. (3) Some notable findings existed in 21 typical coupled samples: (a) After the establishment of nature reserves, the annual NPP increase rate in 76% of samples inside nature reserves and 82% of samples inside national nature reserves are apparently higher than that of corresponding samples outside nature reserves. (b) The ecological protection effectiveness in Central Kunlun, Changshagongma, Zoige Wetland, and Siling Co nature reserves is significant; in most parts of the Three Rivers' Source and Qiangtang nature reserves, the protection effectiveness is relatively significant, while in south-east Manzetang and north Taxkorgan, the protection effectiveness is not obvious. (c) The ecological protection effectiveness is significant in nature reserves consisting of meadow; however, it is weak in nature reserves covered by steppe.

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    The Dynamic Land Ecosystem Model (DLEM) for Simulating Terrestrial Processes and Interactions in the Context of Multifactor Global Change
    TIAN Hanqin, LIU Mingliang, ZHANG Chi, REN Wei, XU Xiaofeng, CHEN Guangsheng, LU
    Acta Geographica Sinica    2010, 65 (9): 1027-1047.   doi: 10.11821/xb201009001
    Abstract1718)      PDF (1501KB)(131460)      

    The Dynamic Land Ecosystem Model (DLEM) was developed to meet critical needs for understanding and predicting the large-scale patterns and processes of terrestrial ecosystems and continental margins, and complex interactions among climate, ecosystem and human in the context of multifactor global change. The DLEM couples major biophysical, biogeochemical, vegetation dynamical and land use processes, and works at multiple scales in time step ranging from daily to yearly and spatial resolution from meters to kilometers, from region to globe. The DLEM is characterized by the following features: 1) multiple factors driven; 2) fully-coupled cycles of carbon, nitrogen and water; 3) concurrently simulation of major greenhouse gases (CO2, CH4, N2O, & H2O); 4) dynamically tracking changes in land cover/use and vegetation distribution. The model has been validated against site-specific measurements across the globe and applied at various scales. In this paper, we have briefly addressed model structure, parameters, key processes and major input/output variables. As a case study, we presented the simulated global fluxes of net primary productivity, evapotranspiration and methane during 1948-2005 and their spatial patterns in the year 2000. We also identified major gaps in terrestrial ecosystem modeling and field observations, and further discussed some critical future research needs.

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    Cited: Baidu(17)
    Spatio-temporal characteristics of cultural sites and an analysis of their driving forces in the Ili River Valley in historical periods
    Fang WANG, Xiaolei ZHANG, Zhaoping YANG, Fuming LUAN, Heigang XIONG, Zhaoguo WANG, Hui SHI
    Acta Geographica Sinica    2015, 70 (5): 796-808.   doi: 10.11821/dlxb201505010
    Abstract1548)   HTML21)    PDF (3187KB)(113295)      

    This paper presents an analysis of the spatio-temporal distribution of cultural sites in the Ili River Valley in Northwest China based on the application of ArcGIS software. It further explores the relationships between the spatio -temporal evolution of the sites, human history, and the natural environment. The results indicate that the numbers and proportions of the sites, and the frequency of their occurrence, exhibited an inverted V-shaped change trend during six historical periods. These covered the initial, peak, and declining stages of six periods extending from the Xia-Western Zhou dynasties to the Qing-Modern period. The spatial distribution pattern shifted from "high in the east and low in the west" during the first three periods to "high in the west and low in the east" during the latter three periods, illustrating a change in the spatial center of gravity of human activities. The sites were mainly distributed on slopes of grades 1-5. The proportion of sites increased from 75% during the Spring and Autumn-Qin dynasties to 93.75% during the Qing-Modern period. The concentrated distribution of site elevations shifted from grades 4-8 during the Spring and Autumn-Qin dynasties, and the Western Han-Northern and Southern dynasties to grades 1-4 during the latter three periods. The number of sites showed a shifting trend from high mountains and hills to low plains, and from high slopes to low slopes. In particular, the evolutionary pattern of sites in the study area exhibited a special "moist" pattern of migration from middle and upstream areas to downstream areas, as opposed to the migration pattern of sites located in typical arid areas. The paper also includes a discussion of factors influencing the distribution and spatio -temporal evolution of cultural sites, notably, human factors such as politics, economy, and productivity, and natural factors such as geomorphology, altitude, slope, and climate. Although the distribution and spatio -temporal evolution of cultural sites exhibited an orientation toward natural laws pertaining to factors such as river valleys, terraces, plains, and water resources, they presented a significant orientation toward laws, relating to human-driven forces including productivity levels, political stability, economic development, business and trade, and transport, which were more evident during the latter historical periods.

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    Research on administrative divisions based on functional areas analysis: A case of Shaoxing metropolitan area
    Chaolin GU, Ying WANG, Yuan SHAO, Jiang GU
    Acta Geographica Sinica    2015, 70 (8): 1187-1201.   doi: 10.11821/dlxb201508001
    Abstract1124)   HTML28)    PDF (7294KB)(111162)      

    This paper established a research framework for administrative divisions based on functional areas analysis. Firstly, data related to natural conditions, history, socio-economy, transportation and information across Shaoxing are anchored to several small geographical units - blocks or small towns, which forms the basis to identify the interdependence between the units from different levels, and provides the proof of spatial flexibility for urban diversity. Subsequent analysis was concentrated on the division of functional areas through factor analysis and cluster analysis, which provides scientific foundation for the re-organization of the functional areas. On the basis of the research framework, with Shaoxing city as an example, the study indicates that the geographic, socio-economic, transportation and information connections between current administrative districts in Shaoxing have already broken through the limitation of administrative demarcation. Administrative divisions based on functional areas should be enhanced to further stimulate regional development. On the one hand, this approach ensures the accordance between administrative divisions and functional areas, which will facilitate the regional integration and socio-economic development; on the other hand, the administrative divisions dispel the shielding effect of segmentation between natural system and socio-economic system, which would exert positive influence for Shaoxing on promoting the development of surrounding areas. In all, this paper concludes that the administrative divisions based on the analysis of the function areas has exceptional importance and significance on the fast proceeding of physical environmental and socio-economic development.

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    Cited: Baidu(13)
    Correlation analysis between vegetation coverage and climate drought conditions in North China during 2001-2013
    Shuyi ZHAO, Zhaoning GONG, Xuying LIU
    Acta Geographica Sinica    2015, 70 (5): 717-729.   doi: 10.11821/dlxb201505004
    Abstract2048)   HTML29)    PDF (4046KB)(111070)      

    Based on previous studies, the climate drought index can be used to assess the evolution trend of ecological environment under various arid climatic conditions. It is necessary for us to further explore the relationship between vegetation coverage (index) and climate drought conditions. Therefore, in this study, based on MODIS-NDVI products and meteorological observation data, the Palmer Drought Severity Index (PDSI) and vegetation coverage in North China were first calculated. Then the interannual variation of PDSI and vegetation coverage over 2001-2013 was analyzed by using a Theil-Sen slope estimator. Finally in an ecoregion perspective the correlation between them was discussed. The experimental results demonstrated that PDSI index and vegetation coverage value varied over different ecoregions. During the period 2001-2013, vegetation coverage increased in southern and northern mountains in North China, while it showed a decreasing trend in Beijing-Tianjin-Tangshan City Circle area and suburban agricultural zone. During the 13 years, the climate of the northeastern part of North China became more humid, while in the southern part of North China, it tended to be dry. According to the correlation analysis results, 73.37% of North China had a positive correlation between the vegetation coverage and climate drought index. A negative correlation was observed mainly in urban and periurban areas of Beijing, Tianjin, Hebei Province and Henan Province. In most parts of North China, drought conditions in summer and autumn had more influence on vegetation coverage.

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    Dynamic trends and driving forces of land-use intensification in the cultivated land of China
    Guogang WANG, Yansui LIU, Yangfen CHEN
    Acta Geographica Sinica    2014, 69 (7): 907-915.   doi: 10.11821/dlxb201407003
    Abstract835)   HTML16)    PDF (5716KB)(109411)      

    The aim of this study is to establish several important factors representing the land-use intensification in the cultivated land (denoted by CII) using a multi-dimensional approach for achieving realistic and practical cultivated land use policies. For this reason, the theoretical framework was firstly built to explain the changes of land-use intensification in the cultivated land, and then the variables and index were further developed for characterizing the dynamic trends and driving forces of the land-use intensification in the cultivated land at provincial level. Results indicate that the extent of CII obviously increased during the period from 1996 to 2008 due to the extensively use of fertilizers, machinery and pesticide, the increased labor and capital input as well as the intensified land use. Moreover, the principal component regression results show that the productivity of cultivated land, the economic benefits of cultivated land, the labor productivity and the land use conversion are the main factors affecting the village development. The first three factors play a positive role while the last one produces a negative effect on the land-use intensification in the cultivated land. According to these results, main policies for sustainable intensification in cultivated land are formulated. Firstly, the sustainable pathways for intensification should be adopted to reduce the unsustainable uses of chemical fertilizer, agricultural chemicals and etc. Secondly, the condition for agricultural production should be further improved to increase the cultivated land productivity. Thirdly, it is necessary and helpful for improving labor productivity and land use efficiency from the viewpoint of speeding up the cultivated land circulation.

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    Cited: Baidu(34)
    Temporal-spatial pattern and contributing factors of urban RBDs in Beijing
    He ZHU, Jiaming LIU, Hui TAO, Le LI, Run WANG
    Acta Geographica Sinica    2015, 70 (8): 1215-1228.   doi: 10.11821/dlxb201508003
    Abstract1992)   HTML23)    PDF (3263KB)(93735)      

    Urban RBD (Recreational Business District), a place where local residents and tourists go for leisure, tourism and consumption, is widely accepted as an indispensable component of urban recreation system in recent years. However, existing research in urban RBD puts an emphasis on its conceptual aspects (i.e., classification, influence, spatial structure), and empirical and quantitative studies have been largely ignored. Firstly, a summary about urban RBDs’ characteristics from the perspectives of location, scale, users, function, and culture was made. Based on previous literature and RBDs’ characteristics and attributes, this study divides urban RBD into three groups, namely: Large Shopping Center (LSC), Commercial Pedestrian Street (CPS), and Urban Leisure Area (ULA). Quantitative methods, such as Gini Coefficient, Spatial Interpolation, Kernel Density Estimation, and Geographical Detector, were employed to collect and analyse data of three types of urban RBDs in Beijing in 1990, 2000, and 2014, respectively, and the spatial-temporal evolution pattern as well as distribution characteristics of urban RBDs were analyzed with the aid of ArcGIS software. The results show: (1) The total number and scale of urban RBDs in Beijing have been expanding, with urban RBDs increasing by 8.20% and 7.26% per year in 1990-2000, and 2000-2014, respectively; (2) spatial agglomeration of urban RBD in Beijing keeps strengthening, and the trend that all types of urban RBDs in Beijing are spatially agglomerated is continuing; However, there exist some variances in terms of their growth speed and degree; (3) the spatial structure evolution model of urban RBDs in Beijing is as one core concentration—two cores development—multi-core diffusion; (4) According to the statistics from database concerning traffic, resident and tourist density, tourism attractions and land price in Beijing, the results showed that urban RBDs were generally located in areas with low traffic density, tourist attractions, high resident and tourist population density, and relatively high land valuations; (5) tourists density strongly influenced the scale of each urban RBD type, compared with other factors.

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    Cited: Baidu(28)
    The relationship between settlements distribution and environmental changes from the Neolithic to Shang-Zhou periods in north Shandong Province
    GUO Yuanyuan, MO Duowen, MAO Longjiang, WANG Shougong, LI Shuicheng
    Acta Geographica Sinica    2013, 68 (4): 559-570.   doi: 10.11821/xb201304010
    Abstract623)      PDF (3790KB)(93269)      
    Using ArcGIS spatial analyst tools, this study analyzes the spatial and temporal distribution of ancient archaeological sites of six periods from the Neolithic Age to the Shang and Zhou dynasties in northern Shandong province. In addition, combined with the experimental analysis of Shuangwangcheng (SWC) profiles and previous studies, the relationship between site distribution and environmental factors is discussed. The results show that during the period of 8000-5000 aBP, the climate was warm and humid and the sea level was relatively high; therefore, archaeological settlements were mainly distributed on diluvial tablelands and alluvial plain with the altitude ranging from 20 m to 300 m and the slope lower than 2°. However, there were few archaeological sites distributed in the western low-lying plain as the result of frequent flooding events at this stage. After 5000 aBP, the cooling and drying climate and the lowering sea-level prompted the coastward expansion of settlements. Meanwhile, as a result of climatic drying and marine recession, environmental conditions in the western low-lying plain were also ameliorated, which attracted extensive human exploitation. The study area of this period was characterized by the rapid development of prehistoric culture, the intensified social stratification and the emergence of early city-states. However, around 4000 aBP, the abrupt change of climate and the increase in the frequency and intensity of flooding events severely disrupted human activities, which might be the main reason for the decline of the Yueshi culture. During the Shang and Zhou dynasties, the climatic conditions tended to be stable and assumed a mild-dry condition, which promoted the development of the culture to be prosperous again. The previous situation of sparse human settlements due to the lack of freshwater and being unfitted for sedentary agriculture improved during the Shang and Zhou dynasties in northern coastal wetlands. Local residents effectively adapted themselves to the harsh environmental conditions by producing sea-salt, which led to the rapid growth of ancient settlements.
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    Cited: Baidu(13)
    Spatial change of China's grain production based on geographical division of natural factors during 1990-2010
    Haiya XU, Huiyi ZHU
    Acta Geographica Sinica    2015, 70 (4): 582-590.   doi: 10.11821/dlxb201504006
    Abstract1471)   HTML16)    PDF (1488KB)(90799)      

    The spatial pattern of grain production in China has changed remarkably under the background of global change, industrialization and urbanization over the past 20 years. This change has great impacts on grain supply and grain market, efficiency of agricultural resources, disaster risk of agricultural production on national scale, and ecological security on regional scale as well. Current research focused on the spatial change of China's grain production based on three schemes of geographical division including North and South China division, three economic regions, and eight grain-producing bases. These schemes reflected geographical features of grain production in China. In this paper, location quotients of grain production and yield data of 2344 counties were used to analyze variations of grain production in geographical regions defined by disparity of annual precipitation, effective temperature, and landforms. The results indicated that the grain production in all the geographical regions presented an increasing trend during the period 1990-2010. Due to the spatial disparity of regional growth rate, the centre of grain production in China moved northward: from the regions with precipitation over 800 mm to those with precipitation between 400 mm and 800 mm; from subtropical zone to mid-temperate zone and warm-temperate zone; and gradually concentrated in flat plains. The results implied that the change of spatial patterns of China's grain production went against the efficient use of water and heat resources, but it was beneficial to the application of agricultural machines and the improvement of labor productivity. Given the change trends of spatial pattern of grain production, background of climate change, and the national aim of grain security, China should enhance its ability to improve efficiency of water resources and reduce the risk of natural disasters.

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    Cited: Baidu(9)
    Spatial Differences of Variations of Vegetation Coverage in Inner Mongolia during 2001-2010
    MU Shaojie, LI Jianlong, CHEN Yizhao, GANG Chengcheng, ZHOU Wei, JU Weimin
    Acta Geographica Sinica    2012, 67 (9): 1255-1268.   doi: 10.11821/xb201209010
    Abstract1206)      PDF (4188KB)(87821)      
    Global climate change has led to significant vegetation changes in the past half century. Inner Mongolia, most of which was located in arid and semi-arid areas, is undergoing a process of prominent warming and drying. It is necessary to investigate the response of vegetation to the climatic variations (temperature and precipitation) for a better understanding of the accumulated consequence of climate change. Vegetation coverage, which is an important indicator for evaluating terrestrial environment, is used to monitor vegetation change. MODIS-NDVI data and climate data were used to analyze the vegetation dynamics and its relationship with climate change on different spatial (forest, grassland and desert biome) and temporal (yearly and monthly) scales in Inner Mongolia during 2001-2010. It was found that vegetation coverage increased from west to east across Inner Mongolia with a change rate of 0.2/10°N. During 2001-2010, the mean vegetation coverage was 0.57, 0.4 and 0.16 in forest, grassland and desert biome, respectively, exhibiting evident spatial heterogeneities. There is a slight increase of vegetation coverage over the study period. Across Inner Mongolia, the vegetation coverages with extremely significant and significant increase accounted for 11.25% and 29.13% of the total study area, respectively, while those with extremely significant and significant decrease were 7.65% and 26.61%, respectively. The correlation analysis between vegetation coverage and climate shows that annual vegetation coverage was better correlated with precipitation, while the change of monthly vegetation coverage is consistent with both the changes of temperature and precipitation, indicating that the vegetation growth within a year is more sensitive to the joint function of hydrothermal combination rather than either climate factor. The vegetation coverage of forest biome was mainly affected by temperature on both yearly and monthly scales, while that of desert biome was mainly influenced by precipitation on the two temporal scales.
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    Cited: Baidu(118)
    ECOLOGICALLY STRATEGIC POINTS IN LANDSCAPE AND SURFACE MODEL
    Yu Kongjian
    Acta Geographica Sinica    1998, 65 (s1): 11-20.   doi: 10.11821/xb1998s1002
    Abstract542)      PDF (1635KB)(82932)      
    Various processes occur across a landscape, including ecological processes such as the movement of species, the flow of nutrients, the spread of fire and other disturbances, and the diffusion of pollutants; economic processes such as land conversion for agricultural production, marketing of new product, transportation and immigration; political and diplomatic processes such as the construction of political influence sphere at local, national and global scale. At the fact of limited space and resources on the surface of the earth, a generic issue regarding these processes across the landscapes is : how to control (promote or retard) the processes efficiently, namely using less energy and space for a bigger influence sphere.The overall assumption for this issue is that, there are some positions and portion in a land-scape that may have critical influence on a certain process across the landscape. These critical positions in a landscape are called strategic points. Occupancy of these strategic points may give a process the momentum of controlling and covering the landscape more effectively, due to their quality of:Initiative, occupancy of these points may give the process the advantage of leading the game;Co-ordination, occupancy of these points may give the process the advantage of forming an overall influence sphere;Efficiency, occupancy of these points may give the process the advantage of having a bigger coverage of the landscape while costing less energy.By identifying and using these critical positions and portions in the landscape, therefore, may unproportionately increase the efficiency of controlling this process.It is further assumed that, in order to take control of the landscape, the process has to overcome a certain resistance. A resistance surface can therefore visualize the dynamics of the process itself. The resistance surface resembles a topographic surface, indicating where the pro-cess (flow) diverges or converges. It is. therefore, possible to identify strategically important positions or portions in a landscape that may have important influence on the dynamics of the process.Assuming species movement across a landscape is a competitive gaming process of control and coverage against some resistance, this paper discusses a methodology of identifying strategic points according to the properties of resistance surfaces which resembles a gaming board as well as a topographic surface. Three types of resistance surfaces are discussed:The archipelago type: where lower resistance islands are surrounded by higher resistance matrix, representing such landscapes as agricultural fields dotted with native forest patches.The network type; where the lower resistance portions form a linear network surrounded by higher resistance matrix.The plateau type: where, areas with higher resistance are surrounded by lower resistance matrix.Accordingly, five types of strategic points are identified in terms of their locations. They are strategic points at saddle points , at intersections, at the center, at an edge and at a corner. Strategic points for biodiversity conservation are minimax points in a given resistance surface as-sociated with the dispersibility of a certain species. A case study is used to illustrate the method-ology. The rules leading to the strategic points are largely hypothetical, though supported by a limited number of observations. This approach may provide a framework and a new model of thinking for field observations of landscape ecology as well as landscape change.
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    Cited: Baidu(70)
    Temporal and spatial change of stream structure in Yangtze River Delta and its driving forces during 1960s-2010s
    Longfei HAN, Youpeng XU, Liu YANG, Xiaojun DENG, Chunsheng HU, Guanglai XU
    Acta Geographica Sinica    2015, 70 (5): 819-827.   doi: 10.11821/dlxb201505012
    Abstract1299)   HTML19)    PDF (1257KB)(77299)      

    Spatial and temporal variations of river systems in the Yangtze River Delta (YRD) during the 1960s-2010s were investigated based on streams derived from the topographic map in the 1960s, 1980s and 2010s. A list of indices, drainage density (Dd), water surface ratio (WSR), the ratio of area to length of main river (R), evolution coefficient of branch river (K) and box dimension (D), were classified into three types (quantitative, structural, and complex indices) and used to quantify the variation of stream structure. Results showed that: (1) quantitative indices (Dd, WSR) presented a decreasing trend in the past 50 years, and Dd in Wuchengxiyu, Hangjiahu and Yindongnan decreased by about 20%. Structurally, the Qinhuai river basin was characterized by a significantly upward R, and K value in Hangjiahu went down dramatically by 46.8% during the 1960s-2010s. A decreasing tendency in D was found to dominate the YRD, and decreasing magnitude in Wuchengxiyu and Hangjiahu peaked for 7.8%, and 6.5%, respectively in the YRD. (2) Urbanization affected the spatial pattern of river system, and areas with a high level of urbanization exhibited least Dd (2.18 km/km2), WSR (6.52%), K (2.64) and D (1.42), compared with moderate and low levels of urbanization. (3) Urbanization also affected the evolution of stream system. In the past 50 years, areas with high level of urbanization showed a compelling decreasing tendency in quantitative (27.2% and 19.3%) and complex indices (4.9%) and trend of enlargement of main rivers (4.5% and 7.9% in periods of the 1960s-1980s and 1980s-2010s). (4) Expanding of urban land, construction of hydraulic engineering and irrigation and water conservancy activities were the main means.

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    Cited: Baidu(13)
    The spatial-temporal patterns of per capita share of grain at the county level in China: A comparation between registered population and resident population
    LI Yating, PAN Shaoqi, MIAO Changhong
    Acta Geographica Sinica    2014, 69 (12): 1753-1766.   doi: 10.11821/dlxb201412002
    Abstract709)   HTML9)    PDF (6047KB)(62197)      
    Per capita share of grain is a major indicator in studying the supply-and-demand equilibrium of grain. With the rapidly growing floating population in China, it is important for the decision-makers to accurately estimate the distribution of per capita share of grain and its dynamics. The variation of per capita share of grain at the finer spatial scale is ignored by most studies at national or provincial levels. Population data used in the calculation of the per capita share of grain are not consistent, but there is large difference between the size of registered population and resident population in some areas. This inconsistency will greatly influence the interpretation of the spatial pattern and trend of per capita share of grain as well as the food transportation policy. Based on the county-level data of registered population and resident population in China's fifth and sixth censuses, this paper conducts a comparative analysis of spatial-temporal patterns and trends of county-level per capita grain, when either registered or resident population is used. Several spatial data analysis methods are used, such as Global Moran's I, LISA, gravity centers curve and the thematic map series. The results show that: Firstly, per capita share of grain in China demonstrates obvious east-west and south-north divides. Per capita share of grain is significantly correlated over space no matter which population data is adopted. High-high clusters are concentrated in Northeast China, northwestern Xinjiang and parts of Central China. Low-low clusters are mainly distributed in coastal provinces in the middle and lower reaches of the Yangtze River and South China. Such a spatial agglomeration is growing over time. The spatial clusters of high values tend to form in Northeast China, while the cold spots have emerged in Southeast China. Secondly, spatial distribution of per capita share of grain differs a lot when two kinds of population data are used. Such differences grow over time, with most of them concentrated to the south of 800 mm rainfall line as well as in South China and Southwest China. This is in line with the fact that the active regions of floating population are mainly located in the eastern monsoon region to the south of 800 mm rainfall line. Although the spatial pattern of serious food shortage regions is consistent under either population standard, migration has intensified the degree of food shortage in these regions. At the same time, calculation result based on resident population shows that, more commodity grain can be exported by counties in Northeast China, Huang-Huai-Hai Region and Sichuan Province. Thirdly, the gravity center change curve of per-capita share of grain presents an "L" shape and has a greater increase and decrease to the north and southeast respectively. Integrating the thematic map series and gravity centers curve of per capita share of grain, we identify seven kinds of regions: large increase, moderate increase, small increase, zero growth, small decrease, moderate decrease and large decrease. Such patterns differ between the two population criteria.
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    Cited: Baidu(3)
    Spatial-temporal variations of lake ice in the Hoh Xil region from 2000 to 2011
    Xiaojun YAO, Long LI, Jun ZHAO, Meiping SUN, Jing LI, Peng GONG, Lina AN
    Acta Geographica Sinica    2015, 70 (7): 1114-1124.   doi: 10.11821/dlxb201507008
    Abstract1375)   HTML8)    PDF (13671KB)(55013)      

    Based on the boundary data of lakes, some moderate-high resolution remote sensing datasets including MODIS and Landsat TM/ETM+ images and the meteorological data, the spatial-temporal variations of lake ice in the Hoh Xil region during the period 2000-2011 are analyzed by using RS and GIS technology. And the factors affecting the lake ice phenology are also discussed. Some conclusions can be drawn as follows. (1) The freeze-up start (FUS) and freeze-up end (FUE) of lake ice appears in late October - early November, and mid-November - early December, respectively. The duration of lake ice freeze-up is about half a month. The time of break-up start (BUS) and break-up end (BUE) of lake ice is relatively dispersed, and appears in late April - early June, and early May - early June, respectively. The ice duration (ID) and the complete ice duration (CID) of lakes are 196 days and 181 days, respectively. (2) The phenology of lake ice in the Hoh Xil region changed dramatically in the last 10 years. Specifically, the FUS and FUE time of lake ice showed an increasingly delaying trend. In contrast, the BUS and BUE time of lake ice presented an advance. This led to the reduction of the ID and CID of lake ice. The average rates of ID and CID were -2.21 d/a and -1.91 d/a, respectively. (3) The variations of phenology and evolution of lake ice are the results of local and climatic factors. The temperature, lake area, salinity and shape of the shoreline are the main factors affecting the phenology of lake ice. (4) The spatial process of lake ice freeze-up is contrary to its break-up process. The type of lake ice extending from one side of lakeshore to the opposite side is dominant in the Hoh Xil region.

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    Changes of the Differences between Ground and Air Temperature over the Qinghai-Xizang Plateau
    ZHANG Wengang,LI Shuxun,WU Tonghua,PANG Qiangqiang
    Acta Geographica Sinica    2006, 61 (9): 899-910.   doi: 10.11821/xb200609001
    Abstract685)      PDF (1540KB)(53559)      

    The difference between ground soil and air temperature (Ts-Ta) was analyzed and studied by using the data of ground and air temperature of 99 stations over the Qinghai-Xizang (Tibet) Plateau from 1960 to 2000, and its spatial distribution and time changing tendency have been diagnosed by principal component analysis and power spectral analysis methods. The results show that the values of (Ts-Ta) are the biggest in June and the smallest in December. The first three loading eigenvectors reflecting the main spatially anomalous structure of (Ts-Ta) over the Qinghai-Xizang Plateau contains the contrary changing pattern between the northwestern and the southeastern regions, the pattern response of the sea level elevation and the geography, and the pattern response of the distribution of the permafrost. There are four patterns of time evolution including the patterns of monotonous increasing or decreasing trends, the basic stability pattern and the parabola pattern with the minimum value. (Ts-Ta) has a periodic variation of about 2 years. According to the spatial distribution of the third loading eigenvector of (Ts-Ta) over the Qinghai-Xizang Plateau in cool season, the permafrost response region and the seasonal frozen ground response region are identified.

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    Cited: Baidu(17)
    Influences of shrubs-herbs-arbor vegetation coverage on the runoff based on the remote sensing data in Loess Plateau
    Xiaoyan LIU, Changming LIU, Shengtian YANG, Shuangyan JIN, Yajun GAO, Yunfei GAO
    Acta Geographica Sinica    2014, 69 (11): 1595-1603.   doi: 10.11821/dlxb201411001
    Abstract949)   HTML28)    PDF (6027KB)(51557)      

    The impact of vegetation coverage on flood or runoff yield in the Loess Plateau has been extensively studied, but the research has been primarily based on observations from slope runoff plots or secondary forest regions. This paper is based on vegetation information from remote sensing images, measured rainfall and runoff data and water consumed from the related basin in Loess Plateau over nearly 50 years. By introducing the concepts of runoff yield coefficient, flood yield coefficient, base flow yield coefficient, and the percentage of effective vegetation, we proposed the quantitative relation between vegetation coverage extracted from remote sensing images and runoff yield at the watershed scale. The response relations reveal that the runoff yield and flood volume will decrease with the increase of shrubs-herbs-arbor vegetation, especially in the dryer region, and the reduction of the runoff in sand-covered loess region is even more than that in the loess region with similar climate. But the flood volume will be kept at a stable level, when the percentage of effective vegetation is larger than 60%. The river's runoff will be stable at a threshold, which is more than its base-flow at last, with a further increase of vegetation.

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    Cited: Baidu(31)
    The progress of social cultural geography in China in recent 10 years
    Kai BAI, Shangyi ZHOU, Yangyang LV
    Acta Geographica Sinica    2014, 69 (8): 1190-1206.   doi: 10.11821/dlxb201408013
    Abstract989)   HTML21)    PDF (742KB)(50899)      

    Since the new millennium, Chinese society has underwent constant "differentiation" and "change", and typical social and cultural phenomena are emerging unceasingly. Social and cultural geography research has attracted sustained attention from scholars. Based on summary of the evolution of the theory of social cultural geography in foreign context, this paper reviews the concerns and hotspots to which Chinese social cultural geography scholars have been given attention in the past ten years. In addition, combining the current situation of development of China, this research also puts forward some other important research areas that should be concerned, such as social and cultural traits of the indigenous geography, the influence of rights and capital on spatial form of social and cultural and place construction, the phenomenon of mobility and scale effect caused by migration between urban and rural areas. In addition, this paper places emphasis of the dialectical unity between the universality of knowledge and China's own socio-cultural characteristics.

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    Cited: Baidu(9)
    The influence of geographical distribution of commercial bank loan on the bank profit efficiency in China
    Zhimin DAI, Liyan ZHU
    Acta Geographica Sinica    2015, 70 (6): 955-964.   doi: 10.11821/dlxb201506009
    Abstract1530)   HTML14)    PDF (516KB)(46961)      

    The regional development research on commercial banks has always been the focus of financial geography research. At present, there is still debate on whether the geographical decentralization level of commercial bank loan can positively influence bank performance. This paper uses the loan data of 13 listed commercial banks in China releasing to each province during 2007-2013 to analyze the loan releasing geographical distribution characteristics of large-sized commercial banks and small and medium-sized commercial banks and the geographic variation trend of non-performing loans. On such basis, it uses stochastic frontier analysis (SFA) and the basic model of Battese and Collie (1995) to build the trans-log profit function model to conduct empirical analysis of the influence of geographical decentralization level of commercial bank loan on the efficiency of bank profits. Research results show that: (1) Increasing the geographical decentralization level of loan can boost the revenue and profit efficiency for commercial banks in the process of banking operation; (2) Large-sized commercial banks, due to the effect of national policies, cover broader loan releasing areas, and the loan releasing proportion in the central and western regions is significantly higher than that of the small and medium-sized commercial banks, and the average profit efficiency has always been higher than that of the small and medium-sized commercial banks. However, in recent years, with the gradually increasing geographical decentralization level of small and medium-sized commercial banks loan, the gap of profit efficiency between the two has been narrowed; (3) At present, the loan business of some small and medium-sized commercial banks in China still belongs to the relationship loan, and raising the geographical decentralization level of loan will lower their profit efficiency. Therefore, the diversified business operation should be carefully handled and cannot blindly follow it.

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    Landscape Pattern Optimization Based on RS and GIS in Northwest of Beijing
    YUE Depeng, WANG Jiping, LIU Yongbing,LI Hailong, XIE Huaici, WANG Dongmei
    Acta Geographica Sinica    2007, 62 (11): 1223-1231.   doi: 10.11821/xb200711011
    Abstract603)      PDF (2815KB)(42972)      

    Heterogeneity of landscapes is supposed to be of significant importance for biodiversity and ecological function in urban ecosystems.However, land use activities caused primarily by urbanization process has a profound and far-reaching impact on stability of landscape and differences of landscape structure at the regional scale. Therefore, in this paper, the northwest region of Beijing is chosen as a study area and the technologies of remote sensing (RS) and geographical information system (GIS) is applied, and meanwhile the priority is been given to understanding of the spatial-temporal characteristics of landscape pattern change through visually interpreting Landsat TM images of 1989, 1996 and 2005 respectively. It is believed that there are a series of landscape ecological problems because of city expansion, such as low landscape ecological connectivity, simplified landscape structure and more obvious fragmentation of green land patch in the plain areas. Moreover, spatial distribution of green land is unbalanced. In order to solve those problems, according to the principle that the movements of flow, energy and material in a landscape are related to some factors such as distance, time, impedance, etc., this study adopts an accumulative cost distance model, combines with ecosystem services and spatial interactions of landscape types, analyzes the spatial difference of the ecological function and the compactness of landscape structure in the study area, and further discusses the landscape pattern optimization proposal.

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    Cited: Baidu(81)
    The Research Forefront of Physical Geography
    CAI Yun-long,LI Shuang-cheng,FANG Xiu-qi
    Acta Geographica Sinica    2009, 64 (11): 1363-1374.   doi: 10.11821/xb200911008
    Abstract621)      PDF (716KB)(34663)      

    The forefront of physical geography research is driven by social needs. The global concern on resources and environment issues and major issues facing sustainable development of China has a series of demands for physical geography. International Geosphere-Biosphere Program, International Human Dimensions Program of Global Environmental Change, World Climate Research Program, Biological Diversity Program and Earth System Science Partnership contain the forefront of physical geography research. China's State Key Basic Research Program, the priority area of development of Earth Sciences Department of National Natural Science Foundation of China, State Science and Technology Support Program etc. have conducted a series of cutting-edge physical geography research. A number of new methods and techniques for physical geography research have emerged in data collection, model simulation, laboratory analysis, studies on physical geographical processes and environmental change and global physical geographical research.

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    Cited: Baidu(30)
    Research framework of ecosystem services geography from spatial and regional perspectives
    Shuangcheng LI, Jue WANG, Wenbo ZHU, Jin ZHANG, Ya LIU, Yang GAO, Yang WANG, Yan LI
    Acta Geographica Sinica    2014, 69 (11): 1628-1639.   doi: 10.11821/dlxb201411004
    Abstract978)   HTML8)    PDF (783KB)(33788)      

    The research on ecosystem services has become a hotspot in ecology, geography and other related disciplines at home and abroad. Through reviewing the history of ecosystem service study, it can be found that the research has been gradually transformed from rational paradigm to regional paradigm, and from natural science paradigm to integrated paradigm between natural science and social science. It was characterized by increasing attention to spatiotemporal heterogeneity, spatial flow ability and regional features, and links between ecosystem services and human welfare. Almost all the subdisciplines of geography can find their own research themes in the cascade framework of ecosystem structure and function-service-human benefits and welfare. Due to more participation in the study area of ecosystem services, the geography of ecosystem services which is being constructed as a new branch of geography, not only plays a more important role in the research of ecosystem services, but also can extend the study scope of geography. Based on reviewing the historical process and development trend of the ecosystem service research, the logical necessity, opportunities and challenges of geography in ecosystem services research were analyzed in this paper. To promote the transform of ecosystem service research into geographical context, we proposed that the geography of ecosystem service should be established and well defined as an independent branch of geography. Moreover, a preliminary framework of geography of ecosystem service was described, including the definition, research scope and contents, and the subject position in geography.

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    Cited: Baidu(14)
    Paper writing related to the geographical classification and revisions
    Xin ZHAO, Shujin HE, Lufeng YAO
    Acta Geographica Sinica    2015, 70 (7): 1177-1184.   doi: 10.11821/dlxb201507013
    Abstract802)   HTML13)    PDF (517KB)(33583)      

    Papers related to the classification and revisions aim to examine the spatial and temporal differentiation of geographical elements based on assessment indicators. The main contents include: establishing standards for reasonable classification and revisions, making revisions for geographical elements in a study area according to different levels of assessment indicators, and analyzing the results of classification and revisions in a comprehensive way.

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    Cited: Baidu(1)
    Spatiotemporal difference and determinants of multiplecropping index in China during 1998-2012
    Hualin XIE, Guiying LIU
    Acta Geographica Sinica    2015, 70 (4): 604-614.   doi: 10.11821/dlxb201504008
    Abstract1691)   HTML13)    PDF (1190KB)(32998)      

    This paper examines the trend of multiple cropping index (MCI) change in China at national, regional and provincial levels during 1998-2012. Based on the Theil index, it explores the spatio-temporal difference of MCI in China. In addition, a spatial econometric model is used to identify the determinants of the temporal and spatial differences of MCI from the behavior perspective. The results are summarized as follows: (1) From the national perspective, the MCP shows an increasing trend year by year. (2) At the regional level, Northeast China is the fastest growing area in terms of the MCI, whereas the central region is the slowest growing area. The central region has the highest level of MCI, while the northeast region shows the lowest level. (3) According to the Theil index value, the differences of MCI show a narrowing trend, which is mainly attributed to the differences among the four regions. (4) The MCI shows differences among China's 31 provinces, and the gap is great. (5) The proportion of non-agricultural population has a significant negative effect on the MCI, and the proportion of non-agriculture industry, agricultural policy and the per capita operating arable land have significant positive impact on the MCI. Finally, some policies are suggested to raise the level of China's cultivated cropping, such as transfering rural surplus labor, increasing the farmers' income, accelerating the transfer of cultivated land's right of use, form the scale effect of land use, further supporting and benefiting farmers in underdeveloped regions and major grain producing areas, and strengthening the role of the national agricultural policy.

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    Cited: Baidu(11)
    Spatiotemporal data analysis in geography
    Jinfeng WANG, Yong GE, Lianfa LI, Bin MENG, Jilei WU, Yanchen BO, Shihong DU, Yilan LIAO, Maogui HU, Chengdong XU
    Acta Geographica Sinica    2014, 69 (9): 1326-1345.   doi: 10.11821/dlxb201409007
    Abstract3668)   HTML31)    PDF (7133KB)(32998)      

    Following the emergence of large numbers of spatiotemporal datasets, the literatures related to spatiotemporal data analysis increase rapidly in recent years. This paper reviews the literatures and practices in spatiotemporal data analysis, and classifies the methods available for spatiotemporal data analysis into seven categories: including geovisualization of spatiotemporal data, time series analysis of spatial statistical indicators, coupling spatial and temporal change indicators, detection of spatiotemporal pattern and abnormality, spatiotemporal interpolation, spatiotemporal regression, spatiotemporal process modelling, and spatiotemporal evolution tree. We summarized the principles, input and output, assumptions and computer software of the methods that would be helpful for users to make a choice from the toolbox in spatiotemporal data analysis. When we handle spatiotemporal big data, spatial sampling appears to be one of the core methods, because (1) information in a big data is often too big to be mastered by human physical brain, so has to be summarized by statistics understandable; (2) the users of Weibo, Twitter, internet, mobile phone, mobile vehicles are neither the total population nor a random sample of the total population, therefore, the big data sample is usually biased from the population, and the bias has to be remedied to make a correct inference; (3) the data quality is usually inconsistent within a big data, so there should be a balance between the variances of inferences made by using data with various quality and by using small but high quality data.

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    Cited: Baidu(19)
    Acta Geographica Sinica    2015, 70 (5): 691-695.   doi: 10.11821/dlxb201505001
    Abstract791)   HTML14)    PDF (486KB)(32864)      
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    Incorporating social vulnerability to assess population health risk due to heat stress in China
    Pan XIE, Yanglin WANG, Yanxu LIU, Jian PENG
    Acta Geographica Sinica    2015, 70 (7): 1041-1051.   doi: 10.11821/dlxb201507002
    Abstract935)   HTML5)    PDF (11295KB)(32078)      

    This paper presented a new conceptual framework by taking account of heat stress, social vulnerability, and population exposure. Meanwhile, an index system combining environmental data, demographics data and socioeconomic data has been built for the quantitative assessment of county-level heat stress risk pattern of China. The counties with the greatest vulnerability scores contain the Tarim Basin in Northwest China, Yudong Plain and Huaibei Plain in North China, Sichuan Basin in Southwest China, Jianghan Plain and Dongting Lake Basin in Central China, and Pearl River Basin in South China. The hot spots of heat stress risk are located in Jianghan Plain and Dongting Lake Basin in Central China, Sichuan Basin in Southwest China, the junction of Jiangsu, Zhejiang and Shanghai in East China, and Pearl River Basin in South China, especially the Pearl River Delta Region. The hot spots of vulnerability are located in counties of high heat stress or high social vulnerability level, while the hot spots of risk mainly consist of metropolitan areas with dense population and advanced economic level. The results of dominant factor partition show that heat stress dominant areas are mainly located in basins or plains which are more prone to high temperature, social vulnerability dominant areas are mainly located in less developed counties, and population exposure dominant areas are mainly located in coastal counties with dense population.

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    Cited: Baidu(10)
    A review on evapotranspiration data assimilation based on hydrological models
    Chesheng ZHAN, Qingqing DONG, Wen YE, Huixiao WANG, Feiyu WANG
    Acta Geographica Sinica    2015, 70 (5): 809-818.   doi: 10.11821/dlxb201505011
    Abstract1349)   HTML12)    PDF (715KB)(29285)      

    This paper provided a comprehensive review of evapotranspiration data assimilation based on hydrological model. The difficulty and bottleneck for ET was elaborated to construct data assimilation relationship as a non-state variable, with a discussion and analysis about the feasibility of various hydrological models to assimilate ET. Based on this, a new evapotranspiration assimilation scheme was proposed. The scheme presented developed an improved data assimilation system that use distributed time-variant gain model (DTVGM) which contains evapotranspiration-soil humidity nonlinear time response relationship. Moreover, the evapotranspiration mechanism in DTVGM was improved to perfect the ET data assimilation system.

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    Review on landscape ecological risk assessment
    Jian PENG, Weixiong DANG, Yanxu LIU, Minli ZONG, Xiaoxu HU
    Acta Geographica Sinica    2015, 70 (4): 664-677.   doi: 10.11821/dlxb201504013
    Abstract1181)   HTML9)    PDF (709KB)(29099)      

    Under the background of accelerating global urbanization and environmental change, it is of great significance for ecological risk assessment to identify local ecological elements and processes influencing regional ecological sustainability. Ecological risk assessment has been regarded as one of the key topics in researches on integrated management of social ecological system in the view of physical geography and macro ecology. With a special focus on spatial heterogeneity and the correlations between landscape patterns and ecological processes deriving from landscape ecology, landscape ecological risk assessment (LERA) deepens this topic with a new perspective and paradigm. In this paper, through the contrast among ecological risk assessment, regional ecological risk assessment, and landscape ecological risk assessment, the connotation of LERA is clearly defined. Detailed research progresses on LERA are also discussed and focused on region selection of assessing target, landscape meaning characterization of assessing unit, paradigm uniformity of assessing method, indexation of assessing model, and weight setting of assessing index. Finally, future research prospects on LERA are proposed, including detecting ecological implication in the view of landscape process, applying the scaling concept in risk assessment, quantifying the uncertainty of assessing results, coupling nonlinear ecological model with risk threshold determination, incorporating values of ecosystem services into risk assessment, and integrating multiple ecological models through the identification of source and sink landscape process. A framework has also been constructed to illustrate the logic relationships among the prospects of LERA.

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    Cited: Baidu(33)
    Effect of MAUP in Spatial Autocorrelation
    CHEN Jiangping, ZHANG Yao, YU Yuanjian
    Acta Geographica Sinica    2011, 66 (12): 1597-1606.   doi: 10.11821/xb201112002
    Abstract831)      PDF (918KB)(25994)      
    This research investigated the role of modifiable area unit problem (MAUP) in the spatial autocorrelation on data of per capita GDP of China and grid simulated data. The global Moran's I coefficient was used to explore the MAUP effect of spatial autocorrelation statistics. The results showed that the degree of spatial autocorrelation of variables depends on the size of spatial particles and zone designing methods. However, there is no determined function relationship between the change of spatial units and the autocorrelation. So, how to choose the appropriate size of geographical unit particles and zone designing are very important in the research of spatial autocorrelation. Finally, the study presented an approach based on geostatistical interpolation to decrease MAUP effect in spatial autocorrelation analysis.
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    Cited: Baidu(12)
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