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1.
环渤海滨海湿地时空格局变化遥感监测与分析 总被引:8,自引:2,他引:8
基于多期Landsat TM 等遥感数据, 采用目视解译和实地样点采集相互支撑的方法, 完成了环渤海
地区2000 年、2005 年及2008 年湿地提取和分类; 运用单一类型变化率模型、区域动态度模型和动态转移矩
阵, 揭示了环渤海湿地的时空格局、变化特点和驱动机制。研究显示环渤海地区的8 类湿地中, 属于人工湿
地类型的盐场和水库坑塘面积比例大且近8 年增长速度也最快, 年均分别增加205.52 km2 和146.10 km2, 滩
地和海涂减少最明显; 环渤海地区的三大流域中, 黄河流域湿地变化最显 相似文献
2.
Alan T. Murray 《Journal of Geographical Systems》1999,1(4):367-383
Spatial analysis is an important area of research which continues to make major contributions to the exploratory capabilities
of geographical information systems. The use and application of classic clustering methods is being pursued as an exploratory
approach for the analysis of spatially referenced data. Numerous potential clustering approaches exist, so research assessing
the relative differences of these approaches is important. This paper evaluates the median and central points optimization
based clustering approaches for use in the context of exploratory spatial data analysis. Functional and visual comparisons
using three spatial applications across a range of cluster values are carried out. The empirical results suggest that these
two clustering approaches identify very similar groupings. The significance of this finding is that the development of clustering
tools for exploratory analysis may be limited to the median based approach given relative computational and solvability considerations.
Received: 28 September 1998/Accepted: 9 August 1999 相似文献
3.
利用夜间灯光数据的城市群格局变化分析 总被引:3,自引:0,他引:3
针对传统的统计数据具有行政单元统计约束的缺点、DMSP/OLS夜间灯光数据存在分辨率低、像元辐射值饱和的问题,该文使用NPP/VIIRS夜间灯光数据、城区边界、列车时刻表、百度地图API等数据,通过空间统计、标准差椭圆、位序-规模分布、空间联系测度研究中国九大城市群2012与2017年的空间格局变化。结果表明:长三角、珠三角、京津冀城市群的灯光总量和平均灯光均位于前列;长三角、珠三角、成渝、哈长、关中平原城市群灯光变分散,京津冀、长江中游、中原、北部湾城市群灯光变集中,成渝城市群夜间灯光重心移动最大,向重庆方向移动;长江中游城市群接近捷夫分布,中原城市群为序列分布,其他城市群为首位分布;长三角、珠三角、京津冀城市群的总体联系强度最高,各城市群边缘中小城市与核心城市空间联系较弱。 相似文献
4.
The aims of this study were to apply, verify and compare a frequency ratio model for landslide hazards, considering future climate change and using a geographic information system in Inje, Korea. Data for the future climate change scenario (A1B), topography, soil, forest, land cover and geology were collected, processed and compiled in a spatial database. The probability of landslides in the study area in target years in the future was then calculated assuming that landslides are triggered by a daily rainfall threshold. Landslide hazard maps were developed for the two study areas, and the frequency ratio for one area was applied to the other area as a cross-check of methodological validity. Verification results for the target years in the future were 82.32–84.69%. The study results, showing landslide hazards in future years, can be used to help develop landslide management plans. 相似文献
5.
Comparison between two time points of the same categorical variable for the same study extent can reveal changes among categories over time, such as transitions among land categories. If many categories exist, then analysis can be difficult to interpret. Category aggregation is the procedure that combines two or more categories to create a single broader category. Aggregation can simplify interpretation, and can also influence the sizes and types of changes. Some classifications have an a priori hierarchy to facilitate aggregation, but an a priori aggregation might make researchers blind to important category dynamics. We created an algorithm to aggregate categories in a sequence of steps based on the categories’ behaviors in terms of gross losses and gross gains. The behavior-based algorithm aggregates net gaining categories with net gaining categories and aggregates net losing categories with net losing categories, but never aggregates a net gaining category with a net losing category. The behavior-based algorithm at each step in the sequence maintains net change and maximizes swap change. We present a case study where data from 2001 and 2006 for 64 land categories indicate change on 17% of the study extent. The behavior-based algorithm produces a set of 10 categories that maintains nearly the original amount of change. In contrast, an a priori aggregation produces 10 categories while reducing the change to 9%. We offer a free computer program to perform the behavior-based aggregation. 相似文献
6.
利用AIRS产品分析中国地区近地面甲烷浓度时空特性 总被引:1,自引:0,他引:1
甲烷(CH4)作为仅次于二氧化碳(CO2)的第二大温室气体,不仅在全球和区域尺度光化学反应中起着重要作用,而且在能量收支平衡及气候变化方面有着重要的影响。2013年,Auqa/EOS的大气红外探测仪(AIRS)热红外近地表CH4产品在AIRS Version6.0产品中发布,其结果尚未在中国进行验证,利用热红外传感器分析中国近地表CH4浓度的时空分布还处于初始阶段。本文利用中国青海瓦里关(WLG)、中国台湾鹿林山(LLN)及蒙古乌兰乌勒(UUM)地基观测资料对AIRS V6.0近地面CH4浓度产品进行了验证,误差在2%以内,二者相关系数r分别为0.68、0.5、0.69,变化趋势一致,进而从地域、季节变化和年际变化3个方面探讨了2003年—2013年中国地区近地面CH4浓度的时空分布特征。结果表明:CH4浓度最低值位于西藏地区(1800 ppbv),高值区位于新疆维吾尔自治区北部、内蒙古自治区及黑龙江北部(1920 ppbv);夏季高,冬季低,季节性变化明显,年际变化基本上呈增长趋势。 相似文献
7.
Yin Hui 《地球空间信息科学学报》2013,16(3):69-72
The methods of deformation analysis and modeling at single point are realized easily now, but available approaches do not make full use of the information from monitoring points and can not reveal integrated deformation regularity of a deformable body. This paper presents a fuzzy clusetering method to analyze the correlative relations of multiple points in space, and then the spatial model for a practical dangerous rockmass in the area of Three Gorges, Yangtze River is established, in which the correlation of six points in space is analyzed by geological investigation and fuzzy set theory. 相似文献
8.
YIN Hui 《地球空间信息科学学报》2000,3(3):69-72
The methods of deformation analysis and modeling at single point are realized easily now,but available approaches do not make full use of the information from monitoring points and can not reveal integrated deformation regularity of a deformable body.This paper presents a fuzzy clusetering method to analyze the correlative relations of multiple points in space,and then the spatial model for a practical dangerous rockmass in the area of Three Gorges,Yangtze River is established,in which the correlation of six points in space is analyzed by geological investigation and fuzzy set theory. 相似文献
9.
利用Landsat TM和IRS P6 LISS III卫星影像及GIS对耕地和耕种模式的时空动态分析(英文) 总被引:2,自引:0,他引:2
The study of the spatial patterns and temporal changes of cropland is important to understand the underlying factors and the
functional effects of the agricultural landscape. On the other hand, crop dynamics mapping is essential to know the overall
agro-spatial diversity of the area. Therefore, this paper addressed a spatio-temporal analysis of cropland and cropping pattern
change in the Bogra district of Bangladesh over the last 16 years (between 1988/89 and 2004/05). In this paper, crop mapping
from multi-temporal and multi-sensor satellite images was described. Landsat TM and IRS P6 LISS III satellite images were
used with GIS for spatial dynamics of cropland and cropping pattern change analysis. First, seasonal cropland maps were derived
from object-based classification of satellite images, then two-date classified image differencing with GIS overlay technique
and decision rules were applied. Cropping pattern change was analyzed in a spatial and quantitative way for the 16 years and
for this, Integrated Land and Water Information System (ILWIS) and Land Change Modular (LCM) of IDRISI Andes were used. The
results showed that in the area, mono crop cultivation was found in summer, but in winter, areas under different crop cultivation
had changed dramatically. Change analysis showed that the changes mainly occurred in the north northwest and southwest of
the areas, and during the time the highest change area was found under the rice-potato pattern.
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10.
11.
针对多时相遥感影像变化检测存在数据不确定性、检测精度不高等问题,提出了一种结合变化向量分析(CVA)和直觉模糊C均值聚类算法(IFCM)的多时相遥感影像变化检测方法. 首先通过CVA构建两个时相遥感影像的差异影像;然后采用直觉模糊C均值聚类算法对差异影像进行聚类得出变化区域和未变化区域;最后对变化检测结果进行二值化处理并进行精度评价. 选取两个时相的高分一号遥感影像和Szada数据集影像作为实验数据. 实验结果表明,采用提出的方法可有效解决传统方法存在的数据不确定性问题,变化检测精度达到了95.92%和92.70%,是一种可行的遥感影像变化检测方法. 研究结果可用于森林动态变化监测、土地复垦利用规划变化分析以及灾损评估. 相似文献
12.
Marie-Hélène Vandersmissen Anne-Marie Séguin Marius Thériault Christophe Claramunt 《Journal of Geographical Systems》2009,11(1):37-65
The research presented in this paper analyzes the emergent residential behaviors of individual actors in a context of profound
social changes in the work sphere. It incorporates a long-term view in the analysis of the relationships between social changes
in the work sphere and these behaviors. The general hypothesis is that social changes produce complex changes in the long-term
dynamics of residential location behavior. More precisely, the objective of this paper is to estimate the propensity for professional
workers to move house after a change of workplace. Our analysis draws on data from a biographical survey using a retrospective
questionnaire that enables a posteriori reconstitution of the familial, professional and residential lifelines of professional
workers since their departure from their parents’ home. The survey was conducted in 1996 in the Quebec City Metropolitan Area,
which, much like other Canadian cities, has experienced a substantial increase in “unstable” work, even for professionals.
The approach is based on event history analysis, a Temporal Geographic Information System and exploratory spatial analysis
of model’s residuals. Results indicate that 48.9% of respondents moved after a job change and that the most important factors
influencing the propensity to move house after a job change are home tenure (for lone adults as for couple) and number of
children (for couples only). We also found that moving is associated with changing neighborhood for owners while tenants or
co-tenants tend to stay in the same neighborhood. The probability of moving 1 year after a job change is 0.10 for lone adults
and couples while after 2 years, the household structure seems to have an impact: the probability increased to 0.23 for lone
adults and to 0.21 for couples. The outcome of this research contributes to furthering our understanding of a familial decision
(to move) following a professional event (change of job), controlling for household structure, familial, professional and
spatial contexts.
相似文献
Marius ThériaultEmail: |
13.
Use of Landsat imagery for the preparation of small scale thematic maps has proved a quicker and economic device. Visually interpreted Land use categories supported by intensive ground truth have been classified for Idukki district in Kerala State. With this quicker device, Landuse and Land Cover clasess are made, considering all the geographical conditions of the area. The classified map can certainly prove a good tool to the planners for acquiring optimal Land use of the area. 相似文献
14.
Spatio-temporal pattern analysis of land use/cover change trajectories in Xihe watershed 总被引:1,自引:0,他引:1
Dongchuan Wang Jianhua Gong Liding ChenLihui Zhang Yiquan SongYujuan Yue 《International Journal of Applied Earth Observation and Geoinformation》2012,14(1):12-21
Human-induced land use/cover change has been considered to be one of the most important parts of global environmental changes. In loess hilly and gully regions, to prevent soil loss and achieve better ecological environments, soil conservation measures have been taken during the past decades. The main objective of this study is to quantify the spatio-temporal variability of land use/cover change spatial patterns and make preliminary estimation of the role of human activity in the environmental change in Xihe watershed, Gansu Province, China. To achieve this objective, the methodology was developed in two different aspects, that is, (1) analysis of change patterns by binary image of change trajectories overlaid with different natural geographic factors, in which Relative Change Intensity (RCI) metric was established and used to make comparisons, and (2) analysis based on pattern metrics of main trajectories in the study area. Multi-source and multi-temporal Remote Sensing (RS) images (including Landsat ETM+ (30 June 2001), SPOT imagery (21 November 2003 and 5 May 2008) and CBERS02 CCD (5 June 2006)) were used due to the constraints of the availability of remotely sensed data. First, they were used to extract land use/cover types of each time node by object-oriented classification method. Classification results were then utilized in the trajectory analysis of land use/cover changes through the given four time nodes. Trajectories at every pixel were acquired to trace the history of land use/cover change for every location in the study area. Landscape metrics of trajectories were then analyzed to detect the change characteristics in time and space through the given time series. Analysis showed that most land use/cover changes were caused by human activities, most of which, under the direction of local government, had mainly led to virtuous change on the ecological environments. While, on the contrary, about one quarter of human-induced changes were vicious ones. Analysis through overlaying binary image of change trajectories with natural factors can efficiently show the spatio-temporal distribution characteristics of land use/cover change patterns. It is found that in the study area RCI of land use/cover changes is related to the distance to the river line. And there is a certain correlation between RCI and slope grades. However, no obvious correlation exists between RCI and aspect grades. 相似文献
15.
近邻指数的城管案件全局分布模式分析 总被引:1,自引:0,他引:1
城市管理案件量化分析是城市管理水平提升的技术支撑。针对城市管理典型案件(街面秩序、市容环境及宣传广告),该文提出了一种热点探测流程和方法,并分析城市管理案件全局分布模式。针对传统量化研究的权重确定未考虑研究对象空间分布的问题,该文提出了基于城管案件近邻指数的权重确定方法,并以此为基础开展城管案件的全局分布模式研究。实验结果表明:3种典型城市管理案件呈显著的聚集分布,并且热点区域符合实验区的实证考察;近邻指数作为权重指标具有客观性、计算高效性,合理反映了城管案件的空间分布。 相似文献
16.
Michael L. Humber Luigi Boschetti Louis Giglio Christopher O. Justice 《International Journal of Digital Earth》2019,12(4):460-484
We characterize the agreement and disagreement of four publically available burned products (Fire CCI, Copernicus Burnt Area, MODIS MCD45A1, and MODIS MCD64A1) at a finer spatial and temporal scale than previous assessments using a grid of three-dimensional cells defined both in space and in time. Our analysis, conducted using seven years of data (2005–2011), shows that estimates of burned area vary greatly between products in terms of total area burned, the location of burning, and the timing of the burning. We use regional and monthly units for analysis to provide insight into the variation between products that can be lost when considering products yearly and/or globally. Comparison with independent, contemporaneous MODIS active fire observations provides one indication of which products most reasonably capture the burning regime. Our results have implications for the use of global burned area products in fire ecology, management and emissions applications. 相似文献
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18.
This paper provides an empirical framework that applies spatial statistics methods to assess the relation between the change
in the geographical clustering of firms and the emergence of urban form. We contend that where firms locate and eventually
cluster give rise to the way commercial and industrial land uses are organized over space, which in turn defines the shape
of urban form. Accordingly, the objectives of our work are twofold: (1) to identify the extent and shape of firm clustering
and co-location at the intra-metropolitan level, and (2) examine how the change in the geographic clustering of different
industries contributes to decentralization and the evolution of urban form. Spatial statistics methods and tools were vital
and helped to fulfill these objectives.
相似文献
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20.
成都市城市扩展时空变化研究 总被引:6,自引:0,他引:6
为了揭示成都市在城市发展过程中产生的变化,该文以成都市多时相、多源空间数据为基础,采用RS与GIS技术提取城市扩展信息,基于空间叠置和缓冲分析技术、运用城市扩展模型对1978年—2010年成都市城市扩展的时空分异特征与城市扩展的驱动力进行分析。结果表明:1978年—2010年,成都市城市扩展呈快速增长的态势,呈"紧凑型圈层式"扩展模式,中心城区扩展主要方向是西北、西和西南;1978年—2002年和2002年—2010年两时段城市扩展时空差异显著;经济发展和城市化发展是成都市城市扩张的主要驱动力。 相似文献