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Spatial pattern recognition for near-surface high temperature increases in mountain areas using MODIS and SRTM DEM
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作者 WANG Yanxia YANG Lisha +1 位作者 HUANG Xiaoyuan ZHOU Ruliang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期2025-2042,共18页
Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are n... Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are necessary but highly difficult due to the complicated environmental conditions and instrumental issues.This paper develops a spatial pattern recognition method to measure the near-surface high temperature increase(NSHTI),one of the lesser-attended changes.First,raster window measurement was proposed to calculate the temperature lapse rate using MODIS land surface temperature and SRTM DEM data.It fully considers the terrain heights of two neighboring cells on opposite or adjacent slopes with a moving window of 3×3 cell size.Second,a threshold selection was performed to identify the NSHTI cells using a threshold of-0.65℃/100 m.Then,the NSHTI strips were parameterized through raster vectorization and spatial analysis.Taking Yunnan,a mountainous province in southwestern China,as the study area,the results indicate that the NSHTI cells concentrate in a strip-like pattern along the mountains and valleys,and the strips are almost parallel to the altitude contours with a slight northward uplift.Also,they are located mostly at a 3/5 height of high mountains or within 400 m from the valley floors,where the controlling topographic index is the altitude of the terrain trend surface but not the absolute elevation and the topographic uplift height and cutting depth.Additionally,the NSHTI intensity varies with the geographic locations and the proportions increase with an exponential trend,and the horizontal width has a mean of about 1000 m and a maximum of over 5000 m.The result demonstrates that the proposed method can effectively recognize NSHTI boundaries over mountains,providing support for the modeling of weather and climate systems and the development of mountain resources. 展开更多
关键词 High temperature increase Mountain areas MODIS spatial pattern recognition Raster window measurement Threshold selection
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Spatial patterns of Picea crassifolia driven by environmental heterogeneity and intraspecifi c interactions 被引量:2
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作者 Changxing Zhao Weijun Zhao +8 位作者 Ming Jin Jiqiang Zhou Feng Ta Lei Wang Wenbo Mou Longju Lei Jinrong Liu Junlin Du Xinglin Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期949-962,共14页
Research on the spatial patterns of tree populations is critical for understanding the structure and dynamic processes of forests.However,little is known about how the underlying drivers shape these patterns and speci... Research on the spatial patterns of tree populations is critical for understanding the structure and dynamic processes of forests.However,little is known about how the underlying drivers shape these patterns and species interactions in forest systems.In this study,spatial point pattern analysis investigated the combined eff ects of intraspecifi c interactions and environmental heterogeneity on the spatial structure and internal maintenance mechanisms of Picea crassifolia in the Qilian Mountain National Nature Reserve,China.Data were obtained from a 10.2-ha dynamic monitoring plot(DMP)and sixteen 0.04-ha elevation gradient plots(EGPs).Under complete spatial randomness,both mature trees and saplings in the DMP demonstratedlarge-scale aggregation with negative correlations.In EGPs,saplings were clustered in small mesoscales,mature trees were randomly distributed,and the interactions of saplingstrees at all elevations were not correlated.By eliminating the interference of environmental heterogeneity through the inhomogeneous Poisson process,saplings in the DMP and EGPs were clustered in small scales and trees randomly distributed.Intraspecifi c associations were negatively correlated,in the DMP and at low elevations,and no correlations in high elevations of EGPs.In the vertical scale,saplings showed a small-scale aggregation pattern with increase in elevation,and the aggregation degree fi rst decreased and then increased.The interactions of saplings-trees and saplings–saplings showed inhibitions at small scales,with the degree of inhibition gradually decreasing.Spatial patterns and associations of adults–adults did not change signifi-cantly.The results revealed that intraspecifi c interactions and environmental heterogeneity regulated the spatial patterns of P.crassifolia at small and large scales,respectively.Environmental heterogeneity might be the most decisive factor aff ecting the spatial patterns of saplings,while trees were more aff ected by intraspecifi c interactions.Moreover,competition between trees in this area could be more common than facilitation for the growth and development of individuals. 展开更多
关键词 Picea crassifolia spatial point pattern analysis Intraspecifi c interactions Environmental heterogeneity
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Optimizing Spatial Pattern Analysis in Serial Remote Sensing Images through Empirical Mode Decomposition and Ant Colony Optimization
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作者 J Srinivasan S Uma +1 位作者 Saleem Raja Abdul Samad Jayabrabu Ramakrishnan 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第4期52-60,共9页
Serial remote sensing images offer a valuable means of tracking the evolutionary changes and growth of a specific geographical area over time.Although the original images may provide limited insights,they harbor consi... Serial remote sensing images offer a valuable means of tracking the evolutionary changes and growth of a specific geographical area over time.Although the original images may provide limited insights,they harbor considerable potential for identifying clusters and patterns.The aggregation of these serial remote sensing images(SRSI)becomes increasingly viable as distinct patterns emerge in diverse scenarios,such as suburbanization,the expansion of native flora,and agricultural activities.In a novel approach,we propose an innovative method for extracting sequential patterns by combining Ant Colony Optimization(ACD)and Empirical Mode Decomposition(EMD).This integration of the newly developed EMD and ACO techniques proves remarkably effective in identifying the most significant characteristic features within serial remote sensing images,guided by specific criteria.Our findings highlight a substantial improvement in the efficiency of sequential pattern mining through the application of this unique hybrid method,seamlessly integrating EMD and ACO for feature selection.This study exposes the potential of our innovative methodology,particularly in the realms of urbanization,native vegetation expansion,and agricultural activities. 展开更多
关键词 spatial pattern analysis EMD ACO
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Effect of Quadrat Shape on Spatial Point Pattern Performance of Haloxylon ammodendron
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作者 Shaohua Wang Longwei Dai 《Open Journal of Ecology》 2024年第1期66-76,共11页
In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Hal... In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Haloxylon ammodendron population. ArcGIS software was used to summarize and analyze the spatial point pattern response of Haloxylon ammodendron population. The results showed that: 1) There were significant differences in the performance of point pattern analysis among different random quadrants. The paired t-test for variance mean ratio showed that the P values were 0.048, 0.004 and 0.301 respectively, indicating that the influence of quadrat shape on the performance of point pattern analysis was significant under the condition of the same optimal quadrat area. 2) The comparative analysis of square shapes shows that circular square is the best, square and regular hexagonal square are the second, and there is no significant difference between square and regular hexagonal square. 3) The number of samples plays a decisive role in spatial point pattern analysis. Insufficient sample size will lead to unstable results. With the increase of the number of samples to more than 120, the V value and P value curves will eventually stabilize. That is, stable spatial point pattern analysis results are closely related to the increase of the number of samples in random sample square analysis. 展开更多
关键词 spatial Point pattern Random Quadrat Quadrat Analysis Quadrat Shape
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Spatial patterns of the main trees in a plant micro-reserve constructed in the 2022 Beijing Winter Olympics mountainous competition zone
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作者 WANG Jian-yong ZHANG Zhi-xiang 《Journal of Mountain Science》 SCIE CSCD 2023年第8期2228-2241,共14页
Several plant micro-reserves were established to preserve the vegetation in local mountain areas during the construction of the Yanqing competition zone of the 2022 Beijing Winter Olympics.The spatial patterns of the ... Several plant micro-reserves were established to preserve the vegetation in local mountain areas during the construction of the Yanqing competition zone of the 2022 Beijing Winter Olympics.The spatial patterns of the main species in one of the micro-reserves and the factors affecting these patterns were characterized in this study.The distribution of arbor species was found to be mostly aggregated,especially at fine scales(<5 m).Minor species were found to be more aggregated than the major species in each forest layer.The spatial patterns were found to be affected by habitat heterogeneity,intraspecific relationships,interspecific competition,and seed dispersal limitation.Habitat heterogeneity was found to affect large-scale spatial patterns,and its effects were observed throughout population development.Interspecific competition is another factor affecting the distribution of the species,and its effects were stronger during the later stages of population development.Habitat heterogeneity was found to affect competition among species and is key for species coexistence.Both these processes are affected by the seed dispersal limitation,and intraspecific relationships are a legacy of seed dispersal.The point patterns can be used as a tool for the initial assessment of the status of communities within micro-reserves.The consideration of these relationships in the development,management,and formulation of policies for micro-reserves in mountainous areas will facilitate the achievement of conservation goals.The careful consideration of habitat conditions when selecting sites for micro-reserves establishment can promote species conservation. 展开更多
关键词 spatial patterns Point patterns Microreserve Juglans mandshurica forest Beijing mountainous area
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The Spatial Patterns of Road Traffic Crash Black Spots and Emergency Facilities in Federal Capital City
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作者 Mamman Saba Jibril David Sesugh Aule Badiatu Danladi Garba 《Journal of Geoscience and Environment Protection》 2023年第2期121-134,共14页
This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The ... This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The aim was to provide stakeholders with information that will aid their understanding of accident prone locations and accessible rescue possibilities for accident victims on the roads in FCT. GPS Map 76S Mark (GARMIN) was used to locate and pick coordinates of data in the study area. A total of 16 possible emergency health care facilities, seventy (70) RTC black spots and Five Zebra point locations were obtained from FRSC. ArcGIS 10.0 was used to compute the data by plotting the coordinates to produce maps of the spatial relationship and to carry out Nearest Neighbour Analysis (NNA). The result was further used to determine the spatial patterns of RTC black spots as well as patterns of the emergency facilities. Generally, the result shows that the spatial trend is turning towards dispersion. However, there is less than 1% likelihood that the dispersed patterns could be the result of random chance. It was recommended that, the Federal Road Safety Commission should be staffed with trained professionals that can be responsible for accident data surveillance and analysis using geospatial techniques. 展开更多
关键词 ACCIDENT Black Spot EMERGENCY pattern spatial Zebra Point
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Spatio-temporal patterns of land use change along the Bohai Rim in China during 1985-2005 被引量:9
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作者 郭丽英 王道龙 +2 位作者 邱建军 王立刚 刘玉 《Journal of Geographical Sciences》 SCIE CSCD 2009年第5期568-576,共9页
Based on TM image data and other survey materials, this paper analyzed the spatiotemporal patterns of land use change in the Bohai Rim during 1985-2005. The findings of this study are summarized as follows: (1) Lan... Based on TM image data and other survey materials, this paper analyzed the spatiotemporal patterns of land use change in the Bohai Rim during 1985-2005. The findings of this study are summarized as follows: (1) Land use pattern changed dramatically during 1985-2005. Industrial and residential land in urban and rural areas increased by 643,946 hm2 of which urban construction land had the largest and fastest increase of 294,953 hm2 at an annual rate of 3.72%. (2) The outward migration of rural population did not prevent the expansion of residential land in rural areas by 184,869 hm2. This increase reveals that construction of rural residences makes seriously wasteful and inefficient use of land. (3) Arable land, woodland and grassland decreased at a rate of -0.02%, -0.12% and -1.32% annually, while unused land shrank by 157,444 hm^2 at an annual rate of -1.69%. (4) The change of land use types showed marked fluctuations over the two stages (1985-1995 and 1995-2005) In particular, arable land, woodland and unused land experienced an inversed trend of change. (5) There was a significant interaction between arable land and woodland, industrial construction land in urban and rural areas showed a net trend of increase during the earlier period, but only adjustment to its internal structure during the second period. The loss of arable land to the construction of factories, mines and residences took place mainly in the fringe areas of large and medium-sized cities, along the routes of major roads, as well as in the economically developed coastal areas in the east. Such changes are closely related to the spatial differentiation of the level of urbanization and industrialization in the region. 展开更多
关键词 land use spatial pattern spatiotemporal analysis the Bahai Rim
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The spatial-temporal pattern and influencing factors of negative air ions in urban forests, Shanghai, China 被引量:22
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作者 Hong Liang Xiaoshuang Chen +1 位作者 Junguang Yin Liangjun Da 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第4期847-856,共10页
Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions (NAI). The spatio-temporal patterns of negative air ions were explored in Shanghai, ... Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions (NAI). The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations (NAIC) showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles (TSP) were the dominant determining factor of NAIC in sum- mer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai's ongoing urbanization and its impacts on the environment. R is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Fur- thermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to theeffect of urbanization on NAIC. 展开更多
关键词 negative air ion concentration spatial-temporal pattern URBANIZATION urban ecosystem urban greening
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Spatio-temporal Pattern and Spatial Heterogeneity of Ecotones Based on Land Use Types of Southeastern Da Hinggan Mountains in China 被引量:4
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作者 YU Lingxue ZHANG Shuwen +3 位作者 LIU Tingxiang TANG Junmei BU Kun YANG Jiuchun 《Chinese Geographical Science》 SCIE CSCD 2015年第2期184-197,共14页
Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial he... Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial heterogeneity of the ecotones among agricultural land, forest land, and grassland of the southeastern Da Hinggan Mountains in the northeastern China. The change of these delineated ecotones under different slopes and aridity conditions was analyzed by two landscape indices, edge density(ED) and core area percentage of landscape(CPL), to explore the inter-linkage between spatial structure of ecotones and socioeconomic development and land management. Specifically, the ecotones such as agriculture-forest(AF) ecotone, forest-grassland(FG) ecotone, and agriculture-forestgrassland(AFG) ecotone moved from the arid southeast to the humid northwest. The flat area with small slope is more edge-fragmented than the steep area since the ED decreases as the slope increases. The AF ecotone mostly found in the humid region is moving to more humid areas while the agriculture-grassland(AG) ecotone mostly found in the dry region is moving towards the drier region. 展开更多
关键词 ecotones core area percentage of landscape(CPL) edge density(ED) modified moving split window land use pattern spatial heterogeneity
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Spatial-Temporal Features of Wuhan Urban Agglomeration Regional Development Pattern—Based on DMSP/OLS Night Light Data
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作者 Mengjie Zhang Wenwei Miao +2 位作者 Yingpin Yang Chong Peng Yaping Huang 《Journal of Building Construction and Planning Research》 2017年第1期14-29,共16页
Based on the night light data, urban area data, and economic data of Wuhan Urban Agglomeration from 2009 to 2015, we use spatial correlation dimension, spatial self-correlation analysis and weighted standard deviation... Based on the night light data, urban area data, and economic data of Wuhan Urban Agglomeration from 2009 to 2015, we use spatial correlation dimension, spatial self-correlation analysis and weighted standard deviation ellipse to identify the general characteristics and dynamic evolution characteristics of urban spatial pattern and economic disparity pattern. The research results prove that: between 2009 and 2013, Wuhan Urban Agglomeration expanded gradually from northwest to southeast and presented the dynamic evolution features of “along the river and the road”. The spatial structure is obvious, forming the pattern of “core-periphery”. The development of Wuhan Urban Agglomeration has obvious imbalance in economic geography space, presenting the development tendency of “One prominent, stronger in the west and weaker in the east”. The contract within Wuhan Urban Agglomeration is gradually decreased. Wuhan city and its surrounding areas have stronger economic growth strength as well as the cities along The Yangtze River. However, the relative development rate of Wuhan city area is still far higher than other cities and counties. 展开更多
关键词 NIGHT LIGHT DATA URBAN spatial pattern Economic DISPARITY pattern Wuhan URBAN Agglomeration
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Spatial-temporal analysis of wetland landscape pattern under the influence of artificial dykes in the Yellow River delta 被引量:1
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作者 Xin Fu Gaohuan Liu +2 位作者 Siyue Chai Chong Huang Fadong Li 《Chinese Journal of Population,Resources and Environment》 2013年第2期109-117,共9页
The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes o... The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal wetland.Our study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt fields.The results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the YRD.The dykes created conditions for the development of artificial wetlands.However,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period. 展开更多
关键词 artificial DYKES COASTAL WETLAND COASTAL zone of the YELLOW River DELTA LANDSCAPE pattern spatial-temporal analysis
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Geostatistical Analysis on Spatial Patterns of Eggs and Larvae of Kytorhinus immixtus
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作者 张大治 陈小蔚 +1 位作者 贺达汉 范玉婷 《Plant Diseases and Pests》 CAS 2011年第1期24-27,70,共5页
[ Objective ] The paper was to study the spatial distribution pattern and spatial correlation of eggs and larvae of Kytorhinus immixtus. [ Method ] By using geostatistical principles and methods, the number of eggs an... [ Objective ] The paper was to study the spatial distribution pattern and spatial correlation of eggs and larvae of Kytorhinus immixtus. [ Method ] By using geostatistical principles and methods, the number of eggs and larvae ofK. immixtus was investigated, and the obtained data were analyzed. [Result]The cir- cular model was the best fitting model for eggs and larvae of/C immixtus, and the spatial distribution pattern was aggregated distribution with a spatial correlation, and their variation ranges were 18.899 -62.922 and 13.464 -47.455. The distribution pattern of eggs and larvae of K.immistus was simulated by using ordinary Kriging method, and the result showed that their distributions had obvious agitated character, the aggregated intensity in the core area of patch was significantly higher than that in the edge. There was anisotropy of aggregation intensity, the aggregation intensity from northeast to southwest direction was significantly higher than that from northwest to southeast direction. [ Conclusion] The spatial distribution pattern of eggs and larvae of K. immixtus was aggregated distribution, and the increase of plant distance and fragmentation of patch had a certain control effect on the occurrence of K. immixtus population. 展开更多
关键词 Kytorhinus immixtus spatial patterns GEOSTATISTICS Desert landscape
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Spatial patterns and driving forces of land use change in China during the early 21st century 被引量:167
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作者 LIU Jiyuan ZHANG Zengxiang +8 位作者 XU Xinliang KUANG Wenhui ZHOU Wancun ZHANG Shuwen LI Rendong YAN Changzhen YU Dongsheng WU Shixin JIANG Nan 《Journal of Geographical Sciences》 SCIE CSCD 2010年第4期483-494,共12页
Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of... Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21 st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the "Grain for Green" policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of "Western Development", "Revitalization of Northeast", coupled with rapidly economic development during this period. 展开更多
关键词 land use change spatial pattern driving forces the early 21st century China
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Spatial patterns of urban land use growth in Beijing 被引量:17
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作者 LIU Shenghe, Sylvia Prielei, LI Xiubin(1. Inst. of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China 2. International Institute for Applied System Analysis, A-2361 Laxenburg, Austria) 《Journal of Geographical Sciences》 SCIE CSCD 2002年第3期266-274,共9页
By using digitized land use maps of Beijing in 1982, 1992 and 1997 and employing GIS spatial analysis techniques, this paper conducts an empirical study on the spatial differentiation and spatial patterns of urban lan... By using digitized land use maps of Beijing in 1982, 1992 and 1997 and employing GIS spatial analysis techniques, this paper conducts an empirical study on the spatial differentiation and spatial patterns of urban land use growth in Beijing in the period of 1982–1997. It is observed that urban land use growth in Beijing went beyond the control of urban planning, in terms of the extraordinary high growth rate and undesired spatial pattern. The rate of urban expansion after 1982, which was predominated by growth of industrial land, was extraordinary high compared to its historical period. While its growth centers have been actively shifting toward the northern part, rather than toward the southern and eastern parts as designated by the latest General Plan (1991–2010) of Beijing, its spatial pattern of urban land use growth in general was in distinct concentric sprawl, which seriously violated the General Plan of Beijing. 展开更多
关键词 urban land use spatial differentiation growth pattern GIS BEIJING
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Spatial patterns of ecosystem vulnerability changes during 2001–2011 in the three-river source region of the Qinghai-Tibetan Plateau, China 被引量:16
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作者 GUO Bing ZHOU Yi +8 位作者 ZHU Jinfeng LIU Wenliang WANG Futao WANG Litao YAN Fuli WANG Feng YANG Guang LUO Wei JIANG Lin 《Journal of Arid Land》 SCIE CSCD 2016年第1期23-35,共13页
The three-river source region (TRSR, including Yangtze, Yellow and Lancang rivers), located in the Qinghai-Tibetan Plateau, China, is a typical alpine zone with apparent ecosystem vulnerability and sensitivity. In thi... The three-river source region (TRSR, including Yangtze, Yellow and Lancang rivers), located in the Qinghai-Tibetan Plateau, China, is a typical alpine zone with apparent ecosystem vulnerability and sensitivity. In this paper, we introduced many interdisciplinary factors, such as landscape pattern indices (Shannon diversity index and Shannon evenness index) and extreme climate factors (number of extreme high temperature days, number of extreme low temperature days, and number of extreme precipitation days), to establish a new model for evaluating the spatial patterns of ecosystem vulnerability changes in the TRSR. The change intensity (CI) of ecosystem vulnerability was also analyzed. The results showed that the established evaluation model was effective and the ecosystem vulnerability in the whole study area was intensive. During the study period of 2001–2011, there was a slight degradation in the eco-environmental quality. The Yellow River source region had the best eco-environmental quality, while the Yangtze River source region had the worst one. In addition, the zones dominated by deserts were the most severely deteriorated areas and the eco-environmental quality of the zones occupied by evergreen coniferous forests showed a better change. Furthermore, the larger the change rates of the climate factors (accumulative temperature of ≥10°C and annual average precipitation) are, the more intensive the CI of ecosystem vulnerability is. This study would provide a scientific basis for the eco-environmental protection and restoration in the TRSR. 展开更多
关键词 eco-environmental vulnerability climate factors spatial patterns three-river source region
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Spatial distribution patterns of Symplocos congeners in a subtropical evergreen broad-leaf forest of southern China 被引量:6
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作者 Xiuqing Yang Haibing Yan +2 位作者 Buhang Li Youzhi Han Bo Song 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期765-776,共12页
Studies on spatial distribution of congeneric species can supplement our understanding of species ecological processes. We analyzed population structure, spatial distribution, intra-and interspecific associations amon... Studies on spatial distribution of congeneric species can supplement our understanding of species ecological processes. We analyzed population structure, spatial distribution, intra-and interspecific associations among six Symplocos tree species on a large(50 ha) plot in a subtropical, evergreen broad-leaf forest in southern China using spatial point pattern analysis methods. Our results suggested that the six Symplocos tree species were all clustered at small scales. The aggregation intensity of S. wikstroemiifolia with low abundance but relatively numerous large-diameter trees was much higher than that of the other five Symplocos species that occurred at high abundance but included few large-diameter trees. Spatial associations among the six congeners showed that 12 of 30 pairs were associated positively at small scales, and 13 of 30 pairs were unrelated. For species among different size classes, 79 of 120 pairs were not correlated, and 17 of 120 pairs were associated positively. These results showed insufficient evidence for interspecific competition and congeneric Symplocos species commonly coexist within subtropical plant communities. The spatial patterns of Symplocos species and their correlations changed with size(DBH) class and were simultaneously affected by spatial scales; the intensity of their aggregation and association decreased with increasing area of the sample plot. 展开更多
关键词 Population structure spatial patterns spatial associations SYMPLOCOS
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Using autologistic spatial models to simulate the distribution of land-use patterns in Zhangjiajie, Hunan Province 被引量:6
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作者 WU Guiping ZENG Yongnian +2 位作者 XIAO Pengfeng FENG Xuezhi HU Xiaotian 《Journal of Geographical Sciences》 SCIE CSCD 2010年第2期310-320,共11页
Nowadays, spatial simulation on land use patterns is one of the key contents of LUCC. Modeling is an important tool for simulating land use patterns due to its ability to integrate measurements of changes in land cove... Nowadays, spatial simulation on land use patterns is one of the key contents of LUCC. Modeling is an important tool for simulating land use patterns due to its ability to integrate measurements of changes in land cover and the associated drivers. The conventional regression model can only analyze the correlation between land use types and driving factors but cannot depict the spatial autocorrelation characteristics. Land uses in Yongding County, which is located in the typical karst mountain areas in northwestern Hunan province, were investigated by means of modeling the spatial autocorrelation of land use types with the purpose of deriving better spatial land use patterns on the basis of terrain characteristics and infrastructural conditions. Through incorporating components describing the spatial autocorrelation into a conventional logistic model, we constructed a regression model (Autologistic model), and used this model to simulate and analyze the spatial land use patterns in Yongding County. According to the comparison with the conventional logistic model without considering the spatial autocorrelation, this model showed better goodness and higher accuracy of fitting. The distribution of arable land, wood land, built-up land and unused land yielded areas under the ROC curves (AUC) was improved to 0.893, 0.940, 0.907 and 0.863 respectively with the autologistic model. It is argued that the improved model based on autologistic method was reasonable to a certain extent. Meanwhile, these analysis results could provide valuable information for modeling future land use change scenarios with actual conditions of local and regional land use, and the probability maps of land use types obtained from this study could also support government decision-making on land use management for Yongding County and other similar areas. 展开更多
关键词 land-use patterns spatial simulation autologistic model spatial autocorrelation Yongding County of Zhangjiajie City
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The temporal and spatial patterns and potential evaluation of China's energy resources development 被引量:8
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作者 MA Beibei LU Chunxia +1 位作者 ZHANG Lei CHENG Xiaoling 《Journal of Geographical Sciences》 SCIE CSCD 2010年第3期347-356,共10页
The issue of China's energy supply security is not only the key problem which af- fects China's rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based... The issue of China's energy supply security is not only the key problem which af- fects China's rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based on the notable characteristic of spatial imbalance between energy production and consumption in China, this paper takes the evolution of China's primary energy resources development(excluding hydropower) from 1949 to 2007 as the study object, with the aim to sum up the evolutive characteristics and laws of China's energy resources development in the past nearly 60 years. Then, based on comprehensive considerations of coal's, oil's and natural gas's basic reserves, qualities, geological conditions production status, and ecological service function of every province, this paper adopts development potential index (DP)to evaluate the development potential of every province's en- ergy resources, and divide them into different ranks. Conclusions are drawn as follows: (1) Generally speaking, China's gross energy production was increasing in waves from 1949 to 2007. From the viewpoint of spatial patterns, China's energy resources development has shown a characteristic of "concentrating to the north and central areas, and evolving from linear-shaped to "T-shaped" pattern gradually since 1949. (2) The structure evolution of China's energy resources development in general has shown a trend of "coal proportion is dominant but decreasing, while oil and gas proportions are increasing" since 1949. (3) At the provincial scale, China's energy resources development potential could be divided into large, sub-large, general and small ranks, four in all. In the future, the spatial pattern of China's energy production will evolve from "T-shaped" to "R-shaped pattern". These conclusions will help to clarify the temporal and spatial characteristics and laws of China's energy resources development, and will be beneficial for China to design scientific and rational energy development strategies and plans, coordinate spatial imbalance of energy production and consumption, ensure national energy supply, avoid energy resources waste and disorderly development, and promote regional sustainable development under the globalization back-ground with changeful international energy market. 展开更多
关键词 energy resources development temporal and spatial patterns potential evaluation China
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Evolution and Spatial Patterns of Spheres of Urban Influence in China 被引量:5
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作者 WANG Kaiyong DENG Yu +1 位作者 SUN Daowei SONG Tao 《Chinese Geographical Science》 SCIE CSCD 2014年第1期126-136,共11页
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimize... This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System(GIS).The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors. 展开更多
关键词 SPHERES of URBAN INFLUENCE types of spatial pattern dynamic EVOLUTION URBAN AGGLOMERATION
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Spatial-temporal evolution of vegetation evapotranspiration in Hebei Province,China 被引量:4
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作者 WANG Qian-feng TANG Jia +6 位作者 ZENG Jing-yu QU Yan-ping ZHANG Qing SHUI Wei WANG Wu-lin YI Lin LENG Song 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第9期2107-2117,共11页
Evapotranspiration (ET) is the sum of soil or water body evaporation and plant transpiration from the earth surface and ocean to the atmosphere, and thus plays a significant role in regulating carbon and water resou... Evapotranspiration (ET) is the sum of soil or water body evaporation and plant transpiration from the earth surface and ocean to the atmosphere, and thus plays a significant role in regulating carbon and water resource cycles. The time-series data set from the remote sensing MOLDS product (MOD16) was used to study the spatial-temporal evolution of vegetation evapotranspiration in salinized areas during 2000-2014 by analyzing the variability, spatial patterns and Mann-Kendall (MK) nonparametric trends for the time series. The results indicate that inter-annual and intra-annual variations of ET across various vegetated areas show seasonal changes, with the abnormal months identified. The Cultivated land displays a greater degree of spatial heterogeneity and the spatial pattern of ET in the area covered by broadleaved deciduous forests corresponds to a higher ET rate and increased water consumption. Awidespread decline of ET is observed only in cultivated areas. However, agricultural cultivation doesn't worsen water shortage and soil salinization problems in the region, and water shortage problems are worsening for other vegetated areas. This research provides a basis of reference for the reasonable allocation of water resources and restructuring of vegetation patterns in salinized areas. 展开更多
关键词 EVAPOTRANSPIRATION Hebei Province MODIS spatial pattern VEGETATION spatial-temporal evolution
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