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1.
Area Delineation and Spatial-Temporal Dynamics of Urban Heat Island in Lanzhou City,China Using Remote Sensing Imagery 总被引：2，自引：0，他引：2
Jinghu Pan 《Journal of the Indian Society of Remote Sensing》2016,44(1):111-127
One of the key impacts of rapid urbanization on the environment is the effect of urban heat island (UHI). By using the Landsat TM/ETM+ thermal infrared remote sensing data of 1993, 2001 and 2011 to retrieve the land surface temperature (LST) of Lanzhou City, and by adopting object-oriented fractal net evolution approach (FNEA) to make image segmentation of the LST, the UHI elements were extracted. The G* index spatial aggregation analysis was made to calculate the urban heat island ratio index (URI), and the landscape metrics were used to quantify the changes of the spatial pattern of the UHI from the aspects of quantity, shape and structure. The impervious surface distribution and vegetation coverage were extracted by a constrained linear spectral mixture model to explore the relationships of the impervious surface distribution and vegetation coverage with the UHI. The information of urban built-up area was extracted by using UBI (NDBI-NDVI) index, and the effects of urban expansion on city thermal environment were quantitatively analyzed, with the URI and the LST grade maps built. In recent 20 years, the UHI effect in Lanzhou City was strengthened, with the URI increased by 1.4 times. The urban expansion had a spatiotemporal consistency with the UHI expansion. The patch number and density of the UHI landscape were increased, the patch shape and the whole landscape tended to be complex, the landscape became more fragmented, and the landscape connectivity was decreased. The heat island strength had a negative linear correlation with the urban vegetation coverage, and a positive logarithmic correlation with the urban impervious surface coverage. 相似文献
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泉州市城市化进程中的热岛效应遥感研究 总被引：1，自引：0，他引：1
利用Landsat TM/ETM+ 热红外图像研究了泉州市1989~2000年间城市热岛的分布与变化情况。研究表明，泉州市热岛面积随城市扩展而增大，并与城市扩展方向和发展趋势相同。对不同时相的热力场进行正规化处理以克服不同季节间的温度差异，便于进行比较，并采用景观分析方法对泉州市热力场的形态、特征进行了分析，发现其主要由热团、热环和碎片体组成，最后，提出了治理和改善泉州市热岛效应的有效措施。 相似文献
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本文以河南省漯河市为例,以遥感解译的漯河市近40年来土地利用数据为基础,运用GIS叠置分析、土地利用转移矩阵等空间分析方法,结合景观格局指标,研究其改革开放以来土地利用及景观格局变化特征,为优化土地资源配置及科学的城市规划提供依据。结果表明:(1)1980年至2015年间漯河城镇用地面积呈显著增加趋势,扩张主要占用耕地;(2)林地和农村居民点用地总体呈增加趋势,2000年来其他建设用地面积迅速增加;(3)漯河市各景观类型总体呈平衡发展态势,耕地优势度有所下降,建设用地优势度不断上升;(4)人口增长与经济发展、交通条件改善及政府政策变动是影响漯河市土地利用变化和景观格局演变的主要因素。 相似文献
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Simulation of landscape spatial layout evolution in rural-urban fringe areas: a case study of Ganjingzi District 总被引：2，自引：0，他引：2
In recent years, the rapid expansion of urban spaces has accelerated the mutual evolution of landscape types. Analyzing and simulating spatio-temporal dynamic features of urban landscape can help to reveal its driving mechanisms and facilitate reasonable planning of urban land resources. The purpose of this study was to design a hybrid cellular automata model to simulate dynamic change in urban landscapes. The model consists of four parts: a geospatial partition, a Markov chain (MC), a multi-layer perceptron artificial neural network (MLP-ANN), and cellular automata (CA). This study employed multivariate land use data for the period 2000–2015 to conduct spatial clustering for the Ganjingzi District and to simulate landscape status evolution via a divisional composite cellular automaton model. During the period of 2000–2015, construction land and forest land areas in Ganjingzi District increased by 19.43% and 15.19%, respectively, whereas farmland, garden lands, and other land areas decreased by 43.42%, 52.14%, and 75.97%, respectively. Land use conversion potentials in different sub-regions show different characteristics in space. The overall land-change prediction accuracy for the subarea-composite model is 3% higher than that of the non-partitioned model, and misses are reduced by 3.1%. Therefore, by integrating geospatial zoning and the MLP-ANN hybrid method, the land type conversion rules of different zonings can be obtained, allowing for more effective simulations of future urban land use change. The hybrid cellular automata model developed here will provide a reference for urban planning and policy formulation. 相似文献
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不透水面作为城市发展和生态环境的重要评估因子,在保障生态环境健康和城市可持续发展中具有重大意义。本文以鄂尔多斯为研究区,通过融合多时相Landsat和夜间灯光数据,提取1990—2019年的不透水面信息,并利用重心分析法、标准差椭圆理论和景观指数理论分析时空演变规律。研究结果表明:①1990—2019年鄂尔多斯市不透水面经历了快速扩张;东北部不透水面覆盖度高于西南部;不透水面的扩张模式总体上表现为“向外扩张-向内加密”。②东北部扩张速度减缓,西南部扩张速度增快。③不透水面扩张的方向性减弱;不透水面扩张的方向有由“东北-西南”向“东-西”转变的趋势。④斑块数量及边缘斑块破碎度增加,城市与郊区的连通性增强,城市有向周边郊区扩张的趋势。本文研究对于进一步了解城市生态环境健康与城市可持续发展的相关关系具有一定的参考价值。 相似文献
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James K. Lein 《国际地球制图》2013,28(2):61-70
Abstract The outward expansion of cities in the United States has been a source of concern and policy debate for well over forty years. This sprawling urban landscape has been cited as a contributing factor behind the loss of open space, environmental damage and increased congestion. To better understand urban expansion, monitoring programs are required to facilitate the systematic observation of urban expansion, and to provide critical information in order to adjust urban development policies. Monitoring the urban landscape has been a major application focus of satellite remote sensing technologies. Yet, research has shown that the complexity of the urban landscape frustrates simple characterization of cumulative land cover processes such as sprawl. In this paper an approach to the remote detection and characterization of sprawl is introduced based on the use of Dempster‐Shafer Theory of Evidence. Functioning as a soft‐classification algorithm, Demptster‐Shafer Theory offers a unique solution to the mapping problem when evidence of class structure in underscored by uncertainty. Through the use of this technique it was possible to model uncertainty based on the concept of belief. This conceptualization was instrumental in deciphering the complexities of urban land cover arrangements and offered an alternative logic which enhanced delineation of subtle changes in land cover indicative of sprawl. 相似文献
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城区边界和城区面积是城镇化的重要表征和扩展分析的基础。然而城区边界存在概念和提取标准不统一、精度较低、可比性较差等问题。为此,提出了基于高分辨率影像和地理信息资料辅助的城区半自动化提取方法,充分利用高分辨率影像上的城市景观特征、先验地理信息知识和一系列标准规则,以得到精度高、一致性强的数据。以中国337个地级以上城市为研究区,采用该方法得到了2000年、2005年、2010年、2016年4期城区边界成果,并开展了城区时空扩展及用地效率等相关分析。结果表明:①16年间城区扩展迅速,城区主要集中分布在东部和中部,东西部地区差异大;②城市用地效率与城镇化发展水平显著相关,城区扩展以外延型为主;③大多城市城区扩展超前于人口增长,少量城市城区扩展滞后于人口增长;④城区扩展以占用耕地为主。 相似文献
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基于地理国情数据的城市扩张和生态格局分析——以武汉市为例 总被引：1，自引：0，他引：1
城市扩张是城镇化的主要特征,研究城市扩张规律对城市空间规划、高质量发展提供决策依据。本文以武汉市为研究区,以2015—2018年地理国情监测成果为主要数据源,通过数据整理与提取、计算城市扩张特征指数、提取城市格局变化、计算生态景观指数等处理,对研究区城市扩张和生态格局变化特征进行分析。研究结果表明：2015—2018年间,武汉市从快速扩张阶段逐渐减缓,紧凑度逐渐下降;中心城市扩张主要以种植土地破坏为代价;远城区快速扩张主要以林草面积减少为代价;在生态指数上,各生态景观类型破碎度均有下降,但水域面积保持良好。 相似文献
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Multitemporal land cover classification over urban areas is challenging, especially when using heterogeneous data sources with variable quality attributes. A prominent challenge is that classes with similar spectral signatures (such as trees and grass) tend to be confused with one another. In this paper, we evaluate the efficacy of image point cloud (IPC) data combined with suitable Bayesian analysis based time-series rectification techniques to improve the classification accuracy in a multitemporal context. The proposed method uses hidden Markov models (HMMs) to rectify land covers that are initially classified by a random forest (RF) algorithm. This land cover classification method is tested using time series of remote sensing data from a heterogeneous and rapidly changing urban landscape (Kuopio city, Finland) observed from 2006 to 2014. The data consisted of aerial images (5 years), Landsat data (all 9 years) and airborne laser scanning data (1 year). The results of the study demonstrate that the addition of three-dimensional image point cloud data derived from aerial stereo images as predictor variables improved overall classification accuracy, around three percentage points. Additionally, HMM-based post processing reduces significantly the number of spurious year-to-year changes. Using a set of 240 validation points, we estimated that this step improved overall classification accuracy by around 3.0 percentage points, and up to 6 to 10 percentage points for some classes. The overall accuracy of the final product was 91% (kappa = 0.88). Our analysis shows that around 1.9% of the area around Kuopio city, representing a total area of approximately 0.61 km2, experienced changes in land cover over the nine years considered. 相似文献
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遥感图像的多时相特性为城镇扩展动态监测提供了可供定性及定量分析的丰富来源。本文应用2009~2014年的多源高分辨率遥感卫星影像数据对兰州市城镇扩展进行了年度动态遥感监测分析,监测结果表明:兰州市近几年城镇扩展年际变化明显,与人口、经济和政策的驱动作用紧密相关。基于多源高分辨卫星影像进行城镇扩展年度动态监测的方法具有实用性,并且监测频次高、精度高,更具现势性。 相似文献
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城市扩张的速度和方向已成为社会关注的焦点,利用夜光遥感进行城市扩张驱动力成因分析是近年来的研究热点。本文采用DMSP卫星所获取的年平均中国区域夜光影像数据,首先对1992—2012年共21年的时序夜光影像进行相对辐射定标;其次通过经验阈值法进行城市建成区面积提取,并通过Landsat影像进行精度验证;最后引入计量经济模型,以地级市主政官员政治周期为解释变量,对全国1992—2012年地级市扩张的政策驱动力因素进行了归因分析。通过本文的分析可知,地级市主政官员政治周期的更替对城市扩张方向存在显著影响。 相似文献
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《International Journal of Digital Earth》2013,6(7):675-686
ABSTRACTIn this geo-statistical analysis of change detection, we illustrate the evolution of the built-up environment in Shanghai at the street-block level. Based on two TerraSAR-X image stacks with 36 and 15 images, covering the city centre of Shanghai for the time period from 2008 to 2015, a set of coherence images was created using a small baseline approach. The road network from Open Street Map, a volunteered geographic information product, serves as the input dataset to create street-blocks. A street-block is surrounded by roads and resembles a ground parcel, a real estate property – a cadastral unit. The coherence information is aggregated to these street-blocks for each observation and the variation is analysed over time. An analysis of spatial autocorrelation reveals clusters of similar behaviours. The result is a detailed map of Shanghai highlighting areas of change. We argue that the aggregation and grouping of synthetic aperture radar coherence image information to real-world entities (street-blocks) is comprehensible and relevant to the urban planning process. Therefore, this research is a contribution to the community of urban planners, designers, and government agencies who want to monitor the development of the urban landscape. 相似文献
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Reza Rafiee Abdolrassoul Salman Mahiny Nematolah Khorasani 《International Journal of Applied Earth Observation and Geoinformation》2009
Green spaces play important functions in urban environments. Reducing air pollution, providing shade and habitat for arboreal birds, producing oxygen, providing shelter against winds, recreational and aesthetic qualities and architectural applications are the main functions of urban green spaces. With the rapid change of urban area in Mashad city during the past decades, green spaces have been fragmented and dispersed causing impairment and dysfunction of these important urban elements. The objective of this study was to detect changes in extent and pattern of green areas of Mashad city and to analyze the results in terms of landscape ecology principles and functioning of the green spaces. In this research, we classified a Landsat TM and an IRS LISS-III image belonging to the years 1987 and 2006, respectively. We then used a post-classification comparison to determine the changes in green space areas of Mashad city during the 19 years covered by the images. Then, we applied landscape ecology calculations to derive metrics that quantified pattern of the changes in the green areas. The results showed that during 19 years from 1987, a significant decrease had occurred in the extent of urban green spaces with a concomitant fragmentation resulting in downgrading and destruction of the functions and services these areas provide. We conclude that the general quality of life in the central parts of the city has been diminished. We also state that a combination of remote sensing image classification, landscape metrics assessment and vegetation indices can provide a tool for assessing life quality and its trend for urban areas. 相似文献
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廊坊是京津冀城市群的地理中心,位于京津两个国际都市之间。本文选取廊坊市中心为研究对象,利用高分一号卫星数据和航空影像,分析廊坊市2010~2016年的城市扩张变化情况,为京津冀协同发展制定政策并为城市制订规划提供依据。首先对遥感影像进行预处理,对高分一号卫星影像,按用地类型分别采用监督分类、面向对象和植被指数法提取城市2016年地表现状信息,并进行精度评价;对2010年的航空影像进行数字化,两类数据结合进行基于分类的变化检测和精度评价,分析城市空间变化特征。结果表明,厂房、建筑和未建成区分别采用监督分类、建筑阈值分类和面向对象法分类效果较好;廊坊市城市扩张的驱动力主要为经济发展、政策因素、历史条件、地形等。 相似文献
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基于RS和GIS的北海市城市空间扩展监测分析 总被引：1，自引：0，他引：1
准确判别城市扩展规律、剖析演化过程,对于预测城市未来演化趋势、制定合理的调控政策具有重要的意义。本文以1990年、2000年、2008年和2012年4个具有代表性年份的卫星影像为依据,应用RS和GIS手段提取了北海市城市实体边界,分析了该市扩展空间特征、面积、方向和速度。研究结果表明:22年间北海市城市实体加速扩展,但其建成率基本不变,这种变化反映了城市规划、宏观调控、海岸带利用政策以及交通对城市扩展的影响。 相似文献
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以辽宁省沈抚新城区为研究对象,选择2006、2010及2014年Landsat影像为数据源,利用面向对象方法提取城市生态空间信息,并对研究区内的景观格局动态特征和多方向变化特征进行了相关计算和分析。结果表明:1)多方向变化分析研究区南部城市增长最多,沈抚新城发展中抚顺区域推进较快,不断向沈阳方向发展;2)绿地整体的增加和城市建筑增加呈显著正相关,沈抚新城生态空间结构逐渐靠拢,并向着规划中的打造浑河景观带的目标努力;3)2006~2014年期间,平均斑块面积和最大斑块指数呈增加趋势,散布与并列指数和蔓延度指数逐年递减,说明沈抚同城化过程中景观具有均衡性和规划性。 相似文献
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利用小波变换对影像进行融合的研究 总被引：2，自引：0，他引：2
基于小波变换可以对影像进行正交分解 ,而不丢失原来信号所包含的信息。提出了一种Wallis变换、小波变换和IHS变换相结合用于融合的方法 ,该方法可以有效地提高多光谱影像的空间分辨率 ,同时保持原来多光谱影像的色调。 相似文献