传统聚落景观基因的地理信息特征及其理解     

胡最 《地球信息科学学报》2020,22(5):1083-1094

传统聚落是民族传统文化遗产的重要组成部分,对社会经济和文化建设具有重要的价值。针对现有研究缺乏探讨传统聚落景观基因（简称景观基因）蕴藏的地理信息特征及理解方法,论文从以下方面开展了深入分析：① 地理信息包含了语义描述、几何形态、属性特征、维度、时空框架、尺度、要素相互关系（空间关联）、演化过程（存在状态）等属性;② 景观基因是一种特殊的文化因子,蕴含着丰富的哲理,是认识传统聚落特征的分析方法,也是文化符号的集合;③ 景观基因包含了空间定位、载体特征、历史与文化特征等丰富的地理信息。根据前述分析结果,论文从符号化、数据挖掘、谱系分析与空间格局制图等途径系统地探讨了景观基因地理信息特征的理解方法。论文认为：在地理时空大数据与地理服务日益深化发展的背景下,结合GIS原理探讨景观基因的地理信息特征对于延伸地理信息科学的内涵,深化传统聚落的地学认识,促进人文GIS的发展具有积极的意义,今后应该继续加强相关方法探索。  相似文献   

Decumbent development: Urban sprawl in the Guwahati Metropolitan Area,India     

Chandra Kant Pawe  Anup Saikia 《Singapore journal of tropical geography》2020,41(2):226-247

Urban sprawl has become a global phenomenon as an outcome of growing population and rapid urbanization. Previous studies have addressed the rising incidence of uncontrollable urban development, particularly in peri-urban areas of cities, leading to chronic urban sprawl. The city of Guwahati, a million city in north east India, has expanded significantly in recent years. In this article, the links between population and growth of built-up areas were examined using geo-spatial techniques and remotely sensed datasets. The results indicate that the sprawl has accentuated in recent years. The intensity of land use remained uneven due to marked variations in the distribution of built-up areas, plausibly an outcome of unplanned urban growth. If current trends are anything to go by, future urban sprawl could pose serious threats to the vulnerable eco-sensitive and peri-urban areas of Guwahati. Secondary cities have unfortunately received scant attention in urban policy research, and Guwahati, epitomizes urban woes in a developing country.  相似文献   

基于参考台的盲源分离法在抑制地磁场近场噪音中的应用研究   总被引：2，自引：0，他引：2       下载免费PDF全文

周媛媛  常莹  陈浩  周勇  马永辉  谢成良  何展翔  服部克巳  韩鹏 《地球物理学报》2019,62(2):572-586

随着城市建设的不断发展,地磁场观测受到的人文干扰越来越严重.汽车、地铁、高铁等产生的近场噪音造成了地磁脉动等空间场源信号难以被精确观测,严重影响了地磁观测资料的实际使用价值.因此抑制这些近场噪音、提取空间场源信号具有科学意义和应用价值.本研究将远场参考法和盲源信号分离法相结合,提出了一种能有效分离空间场源信号和近场噪音的方法.首先,基于仿真分析,我们准确分离了不同特征的源信号,阐明了此方法的有效性.然后,我们将该方法应用于日本千叶地区受电车干扰较为严重的实际磁场观测数据,并选用数据质量较高的KAK国际基准台作为远场参考,实现了地磁脉动和电车干扰信号的分离,并在此基础上对观测台站的近场噪音进行了抑制.这些结果表明基于参考台的盲源信号分离法在抑制近场噪音、提取地磁场信号中是有效的,可能在电磁法勘探中具有潜在的应用价值.  相似文献   

高铁震源地震信号的挤压时频分析应用          下载免费PDF全文

王晓凯  陈文超  温景充  宁杰远  李嘉琪 《地球物理学报》2019,62(6):2328-2335

我国每天有数千趟高铁列车驰骋在纵横交错的高铁线路上,构成了十分理想的均布震源,但寻找适合高铁震源地震信号的处理方法是充分挖掘信息的关键.传统的频谱分析结果表明高铁震源所产生的地震信号具有明显的窄带分立谱特征,但无法精确获得高铁震源地震信号的时频变化规律.本文首次将挤压时频分析这种分析工具引入到高铁震源地震信号处理中,对中国南方某高铁沿线采集到的高铁震源地震数据进行了分析.处理结果表明:利用挤压时频分析能够更加精确地刻画频率成分随时间的变化,能够利用单检波器精确刻画高铁列车的运行状态(匀速、加速等);同时利用挤压时频变换还可高精度地重构出所需频带的信号,为提取高铁震源地震信号的特征成分提供了一种有力工具.  相似文献   

全张量磁梯度数据的斜导数特征值边界识别方法研究   总被引：1，自引：0，他引：1       下载免费PDF全文

郭华  韩松  郑强  梁韧  段然  刘浩军  李西子 《地球物理学报》2019,62(9):3580-3590

本文提出了一种全张量磁梯度数据的斜导数边界识别方法，该方法利用全张量磁梯度数据定义了北向斜导数、东向斜导数和垂向斜导数.模型试验表明，北向和东向斜导数无法有效识别磁性异常体边界，异常形态复杂虚假异常较多，而垂向斜导数在高纬度斜磁化或者垂直磁化条件下可以清晰而准确得识别地质体的边界，具有一定的深度识别能力.与现有磁张量梯度的边界识别方法相比，识别效果好，可以有效均衡不同深度地质体的响应.将上述方法应用于大兴安岭地区实测航磁三分量数据转换得到的全张量数据，获得了研究区浅部磁性体的分布，并与三分量数据进行联合解释，取得良好的地质效果.  相似文献   

Three-parameter Radon transform in layered transversely isotropic media     

Mohammad Mahdi Abedi  Mohammad Ali Riahi  Alexey Stovas 《Geophysical Prospecting》2019,67(2):395-407

Radon transform is a powerful tool with many applications in different stages of seismic data processing, because of its capability to focus seismic events in the transform domain. Three-parameter Radon transform can optimally focus and separate different seismic events, if its basis functions accurately match the events. In anisotropic media, the conventional hyperbolic or shifted hyperbolic basis functions lose their accuracy and cannot preserve data fidelity, especially at large offsets. To address this issue, we propose an accurate traveltime approximation for transversely isotropic media with vertical symmetry axis, and derive two versions of Radon basis functions, time-variant and time-invariant. A time-variant basis function can be used in time domain Radon transform algorithms while a time-invariant version can be used in, generally more efficient, frequency domain algorithms. Comparing the time-variant and time-invariant Radon transform by the proposed basis functions, the time-invariant version can better focus different seismic events; it is also more accurate, especially in presence of vertical heterogeneity. However, the proposed time-invariant basis functions are suitable for a specific type of layered anisotropic media, known as factorized media. We test the proposed methods and illustrate successful applications of them for trace interpolation and coherent noise attenuation.  相似文献   

Analysis of Spatio-temporal Land Surface Temperature and Normalized Difference Vegetation Index Changes in the Andassa Watershed,Blue Nile Basin,Ethiopia     

Melkamu Meseret Alemu 《资源与生态学报(英文版)》2019,10(1):77-85

Analysis of the nexus between vegetation dynamics and climatic parameters like surface temperature is essential in environmental and ecological studies and for monitoring of the natural resources. This study explored the spatio-temporal distribution of land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) and the relationship between them in the Andassa watershed from 1986 to 2016 periods using Landsat data. Monthly average air temperature data of three meteorological sites were used for validating the results. The findings of the study showed that the LST of the Andassa watershed has increased during the study periods. Overall, average LST has been rising with an increasing rate of 0.081°C per year. Other results of this study also showed that there has been a dynamic change in vegetation cover of the watershed in all seasons. There was also a negative correlation between LST and NDVI in all the studied years. From this study we can understand that there has been degradation of vegetation and intensification of LST from 1986 to 2016.  相似文献   

离散Fréchet距离在强震台站场地分类中的应用     

梁基冠  程印  赵岑 《震灾防御技术》2019,14(4):731-741

当强震台站场地资料不完整时，所收集到的强震数据因缺乏准确的场地类别信息而难以有效利用。为解决这一问题，本文提出一种基于离散Fréchet距离的强震台站场地分类方法。将获取到的664个KiK-net台站场地按照《建筑抗震设计规范（GB 50011—2010）》进行分类，并构建2个数据集。利用数据集1得到Ⅰ、Ⅱ、Ⅲ类场地标准谱比曲线，并结合离散Fréchet距离对数据集2中的台站进行场地分类，统计分类成功率与误判率。统计结果表明，本文方法能较准确地对场地进行分类，且误判率在可接受范围内。将本文方法分类统计结果与斯皮尔曼秩相关系数法分类的成功率与误判率进行对比，结合本文方法分类后得到的平均谱比曲线，均可表明应用本文方法进行强震台站场地分类具有合理性。  相似文献   

A spatio-contextual probabilistic model for extracting linear features in hilly terrains from high-resolution DEM data     

Xiran Zhou  Samantha T. Arundel 《International journal of geographical information science》2019,33(4):666-686

  相似文献   

Mitigating the effects of sand dunes on seismic data from the Rub al Khali basin,Saudi Arabia     

Mustafa Al-Marzooq  Mamadou S. Diallo  Vincent Etienne  Thierry Tonellot  SanLinn I. Kaka 《Geophysical Prospecting》2019,67(7):1825-1837

The Rub Al Khali region in Saudi Arabia is characterized by the presence of sand dunes separated by salt flats, also called Sabkhas. In general, the elevation of dunes in this region varies between 90 and 250 m above sea level. The presence of these sand dunes, along with the rapidly changing surface topography poses challenges for seismic data acquisition and processing. The high contrast in acoustic impedance between the dune base and the underlying formation often results in amplification of seismic waves that are recorded at stations located on the surface of sand dunes. Attempts to address the issue using conventional surface-consistent amplitude scaling methods without reducing these amplification effects generally fail, thus compromising the suitability of the processed data for amplitude versus offset analysis. In this study, we propose a new reference site technique to reduce the effects of sand dune amplification, enabling the production of data sets that are suitable for amplitude versus offset processing. The proposed technique uses a deterministic approach to derive surface-consistent, frequency-dependent de-amplification functions for shots and stations located on the dunes only. Two-dimensional synthetic and field data examples show that the technique significantly reduces the effects of sand dune amplification.  相似文献