苏州土地利用及热岛效应的时空变化

选取苏州作为研究区,分别利用1986年和2004年2个时相的Landsat5 TM影像数据对研究区土地利用/覆盖类型进行分类,并采用热红外波段进行地表温度反演,在此基础上分析了下垫面类型与热岛效应的时空变化,深入研究了下垫面类型改变对热岛效应的影响。结果表明,近20a苏州市城区大范围扩张,土地利用变化剧烈,整体表现为水体、植被向不透水下垫面的高强度转化;城市热岛范围由老城区向四周成倍扩大,热岛强度由3.12°增至4.76°,热岛效应变化与土地利用时空变化之间具有明显的对应关系。     

不同土地利用类型的城市热环境效应研究——以广州市为例

利用2005年Landsat TM遥感卫星数据,对广州市不同土地利用类型与城市热环境之间的关系进行研究,发现不同土地利用类型对地表温度(LST)的影响具有明显的差异。草地、林地及耕地的LST与归一化植被覆盖指数(NDVI)呈现明显的负相关,水域的LST与归一化水体指数(MNDWI)之间呈现明显负相关,而城镇建设用地指数(NDBI)、未利用土地指数(NDBaI)则与LST呈现明显正相关。最后建立了LST与各土地利用类型表征指数及DEM之间的多元线性回归方程,可用来指示一个地区不同地表覆盖及地形差异导致的地表温度分布,为城市热环境的评价和分析提供依据。     

Monitoring Spatial and Temporal Land Use/Cover Changes; a Case Study in Western Black Sea Region of Turkey

Rapid land use/land cover changes have taken place in many cities of Turkey. Land use and land cover changes are essential for wide range of applications. In this study, Landsat TM satellite imageries date from 1987, 1993, 2000 and 2010 were used to analyse temporal and spatial changes in the Western Black Sea Region of Turkey. Zonguldak and Eregli two largest and economic important cities which have been active coal mining and iron fabric areas. Maximum Likelihood Classification technique was implemented and the results were represented in classes of open area, forest, agricultural, water, mining, urban and pollution in the sea. Urban areas on both cities increased from 1987 to 2010. The agricultural and open areas from 1987 to 2010 decreased in parallel to land use and land cover change in both cities. Meanwhile, forest areas increased continuously with about 20 % from 1987 to 2010 in both cities. As industrial activity, the coal fields doubled from 1987 to 2010.     

Relationship Between Land Cover Ratio and Urban Heat Island from Remote Sensing and Automatic Weather Stations Data

Urban heat island (UHI) effect has a close relation to land covers type. This paper investigates the relationship between land cover ratio and UHI in Guangzhou, south of China using remote sensing and automatic weather stations data. The temperature data were obtained by Automatic weather stations (AWS) of Guangzhou in October, 2004, at the same time with the CBERS remote sensing image acquired. Firstly, the hourly mean temperature was computed from hourly AWS data. Secondly, the CBERS remote sensing image was classified using support vector machine (SVM) and land covers classification were output. Thirdly, the classification result was overlapped with a round buffer with 1.5 KM radius centered on the AWS, and then the land cover ratio, Edge Density (ED) and Mean Fractal Dimension (MFRACT) of buffers were computed out. Finally, the correlation coefficient between hourly mean temperature and land cover ratio, ED and MFRACT was calculated. It concluded that UHI intensity was heavier during nighttime than daytime. Stations with higher vegetation ratio and higher ED had lower heat island effect. On the contrary, stations with higher impervious ratio and lower ED had more serious heat island effect. The positive–negative of correlation coefficient between hourly mean temperature and vegetation ratio during 11:00–17:00 h (local time) was opposite to that during other time. ED was negatively correlated with hourly mean temperature except during 11:00–17:00 h. On the contrary, MFRACT was positively correlated with hourly mean temperature. It implied that fragmentations of patches were favorable to UHI alleviation, and complexities of patch were unfavorable factors.     

长株潭主城区热岛效应时空演化与土地利用变化关联分析

近年来,由快速城市化过程引起的城市生态环境问题日益突出,热岛效应为最显著的现象之一。本文针对长株潭主城区,采用1994、2000、2006、2010与2015年5个时相的Landsat影像进行地表温度反演,通过热岛强度与等级分析比较了长株潭三市的热岛效应时空演化特征;结合各时相土地利用数据,利用灰色关联模型量化分析了热岛效应时空演化与土地利用变化之间的关系。结果表明:长株潭主城区热岛强度与等级均呈增长趋势;2010与2015年,湘潭市热岛强度大于长沙市与株洲市;建设用地有显著增温效应,而草地、水域与未利用地对强热岛区的降温作用明显。     

支持向量机的北京城市热岛模拟:热岛强度空间格局曲面模拟及其应用

将支持向量机(SVM)曲面拟合算法引入城市热岛强度曲面模拟研究,以MODIS的地表温度产品(LST)数据为例,对2006～2008年北京地区城市热岛强度进行支持向量机(SVM)曲面拟合.敏感性分析和精度评价表明该算法精度较高,能够用来表征城市热岛的空间格局特征.应用结果表明,凭借该算法可对地表城市热岛制图.在年内和年际...     

城市热岛时空变化特征及演变规律研究——以扬子江城市群为例

使用MODIS地表温度夏季影像,通过均值-标准差法和空间叠加分析,研究了扬子江城市群2000—2017年城市热岛时空变化与演变规律特征.结果表明:扬子江城市群热岛效应逐年增强,且强热岛主要体现在长江以南的苏州市、无锡市、常州市、南京市4个城市;城市群中各个城市的城市热岛都呈现由主城区向周围扩展的特征,其中,南京市呈现"...     

Spatial and Temporal Relationships among NDVI,Climate Factors,and Land Cover Changes in Northeast Asia from 1982 to 2009

This study uses a multiple linear regression method to composite standard Normalized Difference Vegetation Index (NDVI) time series (1982-2009) consisting of three kinds of satellite NDVI data (AVHRR, SPOT, and MODIS). This dataset was combined with climate data and land cover maps to analyze growing season (June to September) NDVI trends in northeast Asia. In combination with climate zones, NDVI changes that are influenced by climate factors and land cover changes were also evaluated. This study revealed that the vegetation cover in the arid, western regions of northeast Asia is strongly influenced by precipitation, and with increasing precipitation, NDVI values become less influenced by precipitation. Spatial changes in the NDVI as influenced by temperature in this region are less obvious. Land cover dynamics also influence NDVI changes in different climate zones, especially for bare ground, cropland, and grassland. Future research should also incorporate higher-spatial-resolution data as well as other data types (such as greenhouse gas data) to further evaluate the mechanisms through which these factors interact.     

Area Delineation and Spatial-Temporal Dynamics of Urban Heat Island in Lanzhou City,China Using Remote Sensing Imagery

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.     

烟台市海岸地区土地利用变化时空分异研究

海岸线的大规模开发利用活动,加剧了海岸带土地利用/覆被变化,这种变化因离海岸线距离的不同而呈现出明显差异。以烟台市海岸地区为例,利用遥感和GIS空间分析方法揭示这种因海岸区位差异引起的土地利用变化时空格局特征,以期为地方土地资源与海岸线资源合理开发利用提供参考。结果表明:①近20年来烟台海岸地区土地利用变化较为活跃,城镇和其他建设用地扩展明显;海岸区位深刻影响着海岸地区土地利用动态变化率和不同用地类型间的转移特征;②与海岸区位密切相关的自然地理条件和岸线开发利用活动,以及人口增加、经济增长、政策与管理因素是导致烟台海岸地区土地利用变化产生时空分异的主要因素。     

晋城市植被覆盖时空变化与地形效应耦合

植被作为生态系统的基础,是生态循环系统中重要的研究对象,位于黄土丘陵南部的晋城盆地,由于其特殊的地形地貌特征,植被对环境变化极为敏感.基于2006—2015年MOD13的NDVI植被数据和DEM数据,本文选取山西省晋城市作为研究区,获取植被覆盖度的时间序列数据、晋城行政区县界矢量数据,对其数据进行趋势分析和稳定性分析,...     

基于定量遥感的武汉城市热岛强度时空格局演变分析

应用定量遥感揭示武汉市热岛强度在不同季节和不同年份的时空格局演变.首先,选取2002年(1月,3月,7月,10月)及2000年,2004年,2010年7景ETM数据反演地表温度;其次,经热岛强度指数归一化地温数据,使数据间更具可对比性.对比2002年不同季节地温反演数据,分析武汉市热岛强度在不同季节的变化情况及形成原因.比较2000年,2004年,2010年三个不同年份地温数据,探讨热岛强度年际时空格局演变,建立LST与ndvi、城市热岛强度与水域面积间的相关关系,分析武汉市城区多年ndvi均值以及水域面积的时间变化趋势.结果显示:武汉市城市热岛强度存在明显的季节差异;年际热岛强度空间演变格局表现为以沿江地带为中心,以西北和东南两个方向为主向外延展;LST同ndvi呈负相关关系,其中ndvi值下降0.1,则地表温度上升约1.4℃;热岛强度同城市内水域面积大小亦呈负相关;对比分析了城区多年植被覆盖及水体面积变化趋势,总结出绿地等植被覆盖面积逐渐减小及湖泊面积逐步萎缩是造成武汉城市热岛强度增强的主要因素.     

基于遥感影像的城市热岛容量模型及其应用——以北京地区为例

城市热岛的定量化分析对于客观刻画热岛的物理特征、了解其对城市人居环境质量的影响等具有重要意义.针对区域尺度上城市热岛遥感研究缺乏定量、有效衡量指标的状况,为充分反映热岛信号的空间变化特征,按照热岛检测-热岛信号函数模拟-热岛容量建模的思路,建立了城市热岛容量模型.以北京城市热岛为对象的应用实例证明该模型能够综合热岛强度和热岛面积等多方面信息,满足城市热岛定量化分析的需求.研究结果表明,由于不同主导因子的影响,北京城市热岛存在显著的昼夜和季节差异.     

地表覆盖时空分布定量分析与生态荷载评价——以若尔盖湿地国家级自然保护区为例

对若尔盖湿地国家级自然保护区地表覆盖的空间分布格局、变化幅度、主要地类的变化原因以及生态环境状况进行综合分析。研究结果表明:2010、2014年保护区地表覆盖类型主要为草地,占总面积95%以上;过度放牧、鼠虫害、旅游、挖药等多重因素影响,致使保护区地表覆盖类型之间转移较为频繁。目前,保护区人均生态足迹明显小于人均生态承载力,发展处于一种相对可持续的状态。     

城市地表典型遥感参数与热岛效应时空分析研究——以桂林市为例

利用桂林市1991年和2013年的卫星遥感影像数据,分别提取两个时期的归一化建筑指数(NDBI)、归一化植被指数(NDVI)和改进的归一化差异水体指数(MNDWI)3个地表典型参数,并利用回归分析方法,分析了3个地表典型参数与利用Landsat卫星(热红外波段)反演的地表温度(LST)的相关关系。研究结果表明:桂林市中、高、极高温区3个温度类别的变化趋势与桂林市城市扩张趋势基本一致;NDBI与LST成显著的正相关关系,而NDVI、MNDWI则与LST成负相关关系,且各参数对地表温度响应的程度各有差异。该研究成果对于揭示桂林市热岛效应现状、缓解热岛效应及推进桂林市生态城市建设具有一定的参考意义。     

时空约束性GeoCA模型在城市土地利用预测中的应用

通过在传统GeoCA（地理元胞自动机）模型的基础上添加时空影响因素,建立了时空约束性GeoCA模型,对城市土地利用变化进行了预测;在保证土地利用类型转化率精度的前提下,兼顾了时间跨度因素和邻近用地分布因素的影响,实现了真正意义上的土地利用变化预测。     

Land surface temperature and emissivity estimation for Urban Heat Island assessment using medium- and low-resolution space-borne sensors: A review

The Urban Heat Island (UHI) phenomenon, a typical characteristic on urban landscapes, has been recognised as a key driver to the transformation of local climate. Reliable retrieval of urban and intra-urban thermal characteristics using satellite thermal data depends on accurate removal of the effects of atmospheric attenuations, angular and land surface emissivity. Several techniques have been proposed to retrieve land surface temperature (LST) from coarse resolution sensors. Medium spatial resolution sensors like the Advanced Space-borne Thermal Emission and Reflection Radiometer and the Landsat series offer a viable option for assessing LST within urban landscapes. This paper reviews the theoretical background of LST estimates from the thermal infrared part of the electromagnetic spectrum, LST retrieval algorithms applicable to each of the commonly used medium-resolution sensors and required variables for each algorithm. The paper also highlights LST validation techniques and concludes by stipulating the requirements for LST temporal and spatial configuration.     

时序遥感影像的时空特征在土地分类中的应用

基于Landsat时间序列数据的土地覆盖检测成为当前研究热点,但基于时间序列数据空间纹理特征的应用及不同时序特征重要性评估较少.基于时间序列Landsat8数据,在时序光谱特征、指数特征和地形特征基础上引入时序纹理特征,利用随机森林算法建立八种分类模型,对北京密云区进行土地覆盖分类并比较其分类精度,进而基于袋外(OOB...     

长株潭城市群核心区域土地利用/覆盖变化驱动机制定量研究

采用Logistic回归分析法,以长株潭城市群核心区域为研究区域,结合由遥感与GIS方法得到的地形与社会空间数据,在7个空间尺度上构建建设用地、耕地、林地变化的驱动力模型,探讨土地利用/覆盖变化的尺度效应,并在最佳模拟尺度上定性定量分析区域土地利用/覆盖变化的驱动机制。结果表明:不同尺度模型的拟合优度差异明显,呈现波动变化趋势;当模拟尺度为180 m×180 m时,建设用地、耕地和林地的拟合优度均达到最高。对建设用地变化有重要影响的解释变量是到主要道路的距离、到市区环线的距离、到各级政府的距离;对耕地变化有重要影响的解释变量是高程、到市区环线的距离;对林地变化有重要影响的解释变量是到主要道路的距离、到各级政府的距离、到市区环线的距离。