Impact of land use change on soil resources in the peri-urban area of Suzhou city

The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Yangtze River from Shanghai up to Nanjing as well as their satellite cities and towns, forming one of the most densely distributed urban areas in China. This is a case study done in Suzhou city at the center of the Yangtze delta to reflect the impact of urban sprawl on soil resources using satellite images and digital soil databases. The extent of the developed land in the studied area and the impact of development on soil resources at 1:100,000 scale are estimated and the soil types impacted most by urbanization development are determined through overlaying the soil map on the satellite images (Landsat-7) of the studied area at different times (1984, 1995, 2000 and 2003). The methodology for this study consists of analyzing data resulting from using a geographic information system (GIS) to combine urban land use maps of different times derived from satellite images with data on soil characteristics contained in the established soil databases by which some results come into being to present the fast expanding trend of urbanization in the Yangtze delta area, the urban spread and the soils occupied by the urbanization process, and also the quality of the occupied soils.     

基于CBERS-2遥感数据的艾比湖流域景观生态分类系统

景观生态分类是景观生态学研究的一项重要内容,是开展景观评价、规划与管理等工作的基础。应用CBERS-2遥感影像数据,以地质地貌、土地利用/土地覆被状况、地表植被等因子为分类依据,对艾比湖流域景观生态类型进行了自上而下地划分。研究认为:景观生态分类是建立在尺度的基础之上,不同尺度上的分类单元在纵向上构成了景观带至景观元的多等级景观生态分类体系;艾比湖流域景观生态类型可划分为2个景观类(4个景观亚类)、14个景观系、27个景观型,且该分类系统属于景观生态分类等级阶梯中的中尺度分类段;艾比湖流域景观生态分类系统,对进一步认识和科学合理地利用、规划及管理干旱区内陆湖泊流域的景观具有重要意义。     

Spatial predictions of geological rock mass properties based on in-situ interpretations of multi-dimensional seismic data

The article presents a statistical approach to characterize and predict engineering geological conditions in the up to 2000 m deep Faido tunnel and Gotthard base tunnel in Switzerland. Seismic investigations were conducted to improve the technology of interpreting seismic tomographic images. Overall, the goal of this study was to predict spacial maps of geological rock mass properties, such as, uniaxial compressive strength or total fracture spacing, by using up to six seismic features in combination, e.g., compression-wave and shear-wave velocities and dynamic Poisson's ratio. Self-Organizing Mapping (SOM), an artificial intelligent method, was used for the purposes of interpreting multi-dimensional geophysical attributes derived from seismic profiles of tomographic images along tunnel sidewalls. The SOM-method was applied in the Faido tunnel to delineate complex physical relations between the geological and seismic parameters. Then, the method was applied to predict geological properties around a segment of the Gotthard base tunnel with unknown geological–geotechnical conditions. The results illuminate that correlation analyses (pairwise parameter classification) are substantially less powerful than the SOM-method (multi-parameter classification) in order to interpret geological features from seismic in-situ data. Moreover, predicted spatial distributions of the total fracture spacing and the uniaxial compressive strength, for example, corresponded well with drill core and tunnel mapping results. The SOM-approach was a helpful tool for practitioners in predicting zones of instabilities and geological complexity during underground excavation processes of the Gotthard base tunnel. It is suggested to use such an interpretation method as decision support for purposes of sub/surface exploration and long-term geophysical monitoring of large-scale geoengineering projects, such as, disposals of nuclear waste and greenhouse gases or geopower plants for renewable energy (geothermal, biosoils).     

Microstructure characteristics of illite from Chuanlingou Formation of Changcheng System in Jixian County,Tianjin City

The microstructure charateristics of illite from the Chuanlinggou Formation of Changcheng System (Chch) in Jixian County, Tianjin City has been studied by means of high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), X-ray energy dispersive spectrum (EDS) and X-ray powder diffraction (XRD). The Kübler index of "illite crystallinity" is 0.505°△2θ, which indicates that the host rock is in a middle diagenetic stage. The chemical analyses of EDS for illite studied indicate a heavily absent in interlayer cation and an average chemical formula of K0.57(Al1.80Mg0.42Fe2 0.12)∑=2.34 (Si2.92Al1.08)∑=4O10(OH)2. It is found, from one-dimensional lattice images, that the layers of illite not only stack in a flat way but also in a curving way. A "matting fabric" illite structure results from stacking faults. Combined with SAED analysis the illite studied can be affirmed as 1M illite. The two-dimensional lattice images are obtained from [100] and [110] incidences, whose lattice images have the same d-values but different intersecting angles. The two-dimensional lattice image with [100] incidence is orthogonal to each other, whilst that with [110] incidence is oblique. This paper provides some important structure information of authigenic clay minerals for the well-known mesoproterozoic section of Jixian County.     

基于灰度-基元共生矩阵的多光谱遥感影像分类

提出了基于灰度-基元共生矩阵的遥感影像纹理分析的方法,分析了提取的纹理特征,实现了利用模糊C-均值算法对多光谱影像和纹理特征影像进行分类,比较和讨论了各种不同的分类结果.     

激光扫描深度数据配准方法的研究

在对最近对应点迭代方法研究的基础上,提出了数据格网化重组织策略和基于ICP的多级配准方案,在效率和精度上均取得了好的结果。     

高光谱影像能量边缘提取

高光谱影像的能量边缘提取方法的本质是利用高光谱信号的能量相似性与能量分布特征来寻找边缘，从能量边缘图可以提取属于不同地物类别的主要边缘，这些边缘都比较明显与完整。实验结果表明，能量边缘对噪声信号不敏感，与用其他方法寻找边缘的结果相比，能量边缘具有更好的效果。     

基于局域同质性梯度的遥感图像分割方法及其评价

提出了一种针对多波段遥感图像的快速分割方法.该方法首先对遥感图像进行量化,然后提取局域同质性梯度图像,进而利用快速分水岭变换进行初始分割,最后利用改进的区域合并方法获得最终的分割结果.利用Quickbird图像进行了相关的实验,并在像素数量误差准则的指导下进行了分割评价,结果表明所提出的方法是一种有效的遥感图像分割方法,在分割速度和精度等方面优于多分辨率分割方法.     

卫星影像的云雾检测及干扰去除

云雾检测及去除是光学遥感图像处理的难题。厚云雾因具高反射特性，可通过阈值的设定将其检测并去除； 薄云因混有地物 光谱特性而较难检测，需先对影像做相对辐射校正处理，再将影像由RGB转换成HIS彩色模型，并假设薄云雾的加入等于白色颜料的加 入，即仅改变光谱的亮度或饱和度值，色相并无改变，藉此，可用多时段方式检测。实践证明，在HIS系统中可简化薄云雾的检测准 则，大大提高自动化检测云雾的可能性。