国家西部测图工程产品模式设计与实践——以1:50000影像地形图为例     

苏山舞  于荣花  殷红梅  李维庆  陈代蓉 《地球信息科学学报》2011,13(6):763-769

为实现国家西部1∶50 000地形图空白区测图工程:丰富产品种类,拓展服务领域的设计宗旨,根据ISO 9000对产品的概念,提出了西部测图工程整体产品模式,并对其进行细化,建立了国家两部测图工程地形图产品模式.本文以西部测图工程1∶50 000影像地形图的设计与实现为实例,详细介绍了1∶50 000影像地形图测绘新产品...  相似文献   

基于HJ-1B/IRS的重庆市热岛效应监测应用     

罗小波  陈丹  刘明皓  刘强 《地球信息科学学报》2011,13(6):833-839

本文利用MODIS数据反演大气透射率,利用HJ-1B/CCD进行分类,并反演地表比辐射率.在此基础上,借鉴单窗算法,利用HJ-1B/IRS数据反演得到地表温度,并利用MODIS温度产品对反演结果进行了初步验证.最后利用热场变异指数进一步分析重庆的热岛空间分布特征,并对NDVI与NDBI对热岛效应的影响进行了分析.其结论...  相似文献   

Landscape Controls on Structural Variation in Eucalypt Vegetation Communities: Woronora Plateau,Australia     

Ross B. Jenkins  Nicholas C. Coops 《The Australian geographer》2011,42(1):1-17

Quantification of landscape-based vegetation structural variation and pattern is a significant goal for a variety of ecological, monitoring and biodiversity studies. Vegetation structural metrics, derived from airborne laser scanning (ALS or aerial light detection and ranging—LiDAR) and QuickBird satellite imagery, were used to establish the degree of plot-based vegetation variation at a hillslope scale. Topographic position is an indicator of energy and water availability, and was quantified using DEM-based insolation and topographic wetness, respectively, stratifying areas into hot-warm-cold and wet-moist-dry topographic classes. A range of vegetation metrics—maximum and modal canopy height, crown cover, foliage cover, NDVI and semivariance—were compared among randomly selected plots from each topographic class. NDVI increases with increasing landscape wetness, whereas ALS-derived foliage cover decreases with increasing insolation. Foliage cover is well correlated with crown cover (R ² =0.65), and since foliage cover is readily calculable for whole-of-landscape application, it will provide valuable and complementary information to NDVI. Between-plot heterogeneity increases with increasing wetness and decreasing insolation, indicating that more sampling is required in these locations to capture the full range of landscape-based variability. Pattern analysis in landscape ecology is one of the fundamental requirements of landscape ecology, and the methods described here offer statistically significant, quantifiable and repeatable means to realise that goal at a fine spatial grain.  相似文献   

Plant Area Index and microclimate underneath shrub species from a Chilean semiarid community     

Y. Tracol  J.R. Gutiérrez  F.A. Squeo 《Journal of Arid Environments》2011,75(1):1-6

In drylands, environmental conditions under shrub canopy differ from those found in open sites. We should expect that microclimate conditions under shrubs with distinct canopy architecture should also be different. Plant Area Index (PAI) of the three most abundant shrubs species (Porlieria chilensis, Adesmia bedwellii and Proustia cuneifolia) in Bosque Fray Jorge National Park, north-central Chile was measured using a Plant Canopy Analyzer. During two years (2004-2005), we recorded the Relative Humidity and Air Temperature underneath and away from the canopy of the shrubs.The three shrub species showed significant differences in PAI. Microclimate at 30 cm and 2 m above the soil in the open conditions were drier and warmer than underneath shrub canopies. Vegetation patches generate moderate microclimate conditions.Canopy structure can buffer climatic variability, contributing to high herbaceous productivity as well as shrub recruitment. Reflecting shrub architecture and observed PAI values, the lowest microclimate variations were observed under the canopies of P. chilensis, followed by P. cuneifolia and finally A. bedwellii. We bring a novel approach quantifying the Plant Area Index instead of the Plant cover and using a low cost method that integrates the distribution of leaves and may be derived from remote sensing products.  相似文献   

不同预处理方法对尕海沉积物粒度测试的影响   总被引：2，自引：0，他引：2  

李华勇  潘安定  明庆忠 《干旱区地理》2011,(4)

湖泊沉积物粒度是研究湖区古环境演化的一个重要代用指标,粒度测量结果与预处理方法密切相关。从柴达木尕海湖岩心钻孔取48个样品,采用五种预处理方法,运用马尔文2000激光粒度仪进行粒度分析。结果显示经过预处理后平均粒径有不同程度的变细。单独加入H2O2除去样品中的有机质后,粒度分散变细最为明显,变幅可达10%左右,单独加入(NaPO3)6或H2O2处理后,>63μm(粗颗粒组分)粒径百分含量降低8个百分点左右。单独加蒸馏水浸泡、单独加HCl除去碳酸盐类胶结物和先后加H2O2、HCl(、NaPO3)6处理这三种方法分散效果不明显。23～33号样品对预处理的灵敏度最差,其他样品灵敏度稍好,但总体上尕海湖沉积物对预处理作用不敏感。对于性质类似的盐湖沉积物粒度测试,本文推荐加H2O2进行预处理。  相似文献   

地形湿度指数算法误差的定量评价   总被引：2，自引：0，他引：2  

包黎莉  秦承志  朱阿兴 《地理科学进展》2011,30(1):57-64

地形湿度指数(TWI)能够定量指示地形对土壤湿度空间分布的控制,是一种应用广泛的地形属性.目前基于栅格DEM的TWI计算方法结果各异,因此有必要对'TWI算法进行定量评价.对TWI算法通常是应用实际DEM数据进行评价.但实际DEM中存在的数据源误差会干扰对算法误差的评价.针对该问题,本文介绍了一种用不含数据源误差的人造...  相似文献   

城市景观公园对城市热岛调控效应分析——以哈尔滨市为例   总被引：4，自引：0，他引：4  

周东颖  张丽娟  张利  范怀欣  刘栋 《地域研究与开发》2011,30(3):73-78

采用哈尔滨市2007年9月30日Landsat TM数据,基于哈尔滨市地表温度反演结果,对城市公园对热岛效应的影响进行了分析。研究结果表明:哈尔滨市主城区热岛效应明显,高温区呈现集中分布,市区内的公园在高温区域内形成明显的热岛空洞;公园对周围区域降温作用明显,降温效应随距离增加呈递减趋势;在公园周围120 m范围内,不同面积的公园对周围环境温度影响存在明显差异,不同缓冲带的降温幅度存在极显著差异;公园面积和内部平均温度呈显著负相关,即公园面积越大,内部平均温度越低,反之亦然,二者存在显著的回归关系,因此可以通过设计不同面积公园,以实现城市高温区降温效应。研究表明一个大的景观公园的降温效应要强于总面积相等的多个小公园的降温效应。  相似文献   

中国陆地海岸线尺度效应研究(英文)   总被引：2，自引：0，他引：2  

苏奋振  高义  周成虎  杨晓梅  费鲜芸 《地理学报(英文版)》2011,21(6):1101-1111

Spatial scale is a fundamental problem in Geography. Scale effect caused by fractal characteristic of coastline becomes a common focus of coastal zone managers and researchers. In this study, based on DEM and remote sensing images, multi-scale continental coastlines of China were extracted and the fractal characteristic was analyzed. The results are shown as follows. (1) The continental coastline of China fits the fractal model, and the fractal dimension is 1.195. (2) The scale effects with fractal dimensions of coastline have significant differences according to uplift and subsidence segments along the continental coastlines of China. (3) The fractal dimension of coastline has significant spatial heterogeneity according to the coastline types. The fractal dimension of sandy coastline located in Luanhe River plain is 1.109. The dimension of muddy coastline located in northern Jiangsu Plain is 1.059, while that of rocky coastline along southeastern Fujian is 1.293. (4) The length of rocky coastline is affected by scale more than that of muddy and sandy coastline. Since coastline is the conjunction of sea, land and air surface, the study of coastline scale effect is one of the scientific bases for the researches on air-sea-land interaction in multi-scales.  相似文献   

一种基于空间对象的缓冲区分析算法     

崔爽  苏鸿  叶良松  李景文 《地理与地理信息科学》2011,27(1)

在传统缓冲区分析基本思想的基础上,提出基于空间对象缓冲区分析定义,区别在于邻域半径:前者为常量,后者为变量。设计实现基于空间对象缓冲区分析算法,该算法以空间对象为计算粒度,分为计算缓冲区边界点、生成缓冲区多边形、筛选缓冲区多边形内空间对象3个步骤,并从算法执行机理的角度对其做定性与定量评估。结果表明,该算法解决了传统缓冲区分析难以处理图层内以空间实体为分析粒度的问题,时间和空间复杂度亦优于传统缓冲区分析算法。  相似文献   

塞曼石墨炉原子吸收法测定地球化学样品中银元素     

白志斌 《西部资源》2011,(5):55-56

对塞曼效应石墨炉原子吸收法对地质样中痕量银的测定进行了研究。简化了样品处理过程。对地质标样及实际样品分析获得了满意的结果加标回收率为96.2%-103.5%,相对标准偏差为3.04%-4.77%所采用的方法快速、简便,准确。  相似文献