基于环境一号卫星影像的淮南潘集采煤塌陷积水区富营养化评价

通过研究淮南潘集杨庄采煤塌陷积水区水体水质指标与环境一号卫星影像4个波段反射率值之间的关系,针对叶绿素、透明度、总磷、总氮、高锰酸钾指数5项主要水质参数建立了遥感监测模型。采用综合营养状态指数法,评价了该地区水体整体水质富营养化程度。评价结果表明,该塌陷积水区水体为轻度—中度富营养化,与实测水样分析监测的结果基本吻合,证明了水质遥感模型反演技术在当地水质监测中的适用性和可靠性,为实现该地区水质动态监测与预警提供了技术支持。     

Application of an incomplete landslide inventory, logistic regression model and its validation for landslide susceptibility mapping related to the May 12, 2008 Wenchuan earthquake of China

The main purpose of this paper is to present the use of multi-resource remote sensing data, an incomplete landslide inventory, GIS technique and logistic regression model for landslide susceptibility mapping related to the May 12, 2008 Wenchuan earthquake of China. Landslide location polygons were delineated from visual interpretation of aerial photographs, satellite images in high resolutions, and verified by selecting field investigations. Eight factors, including slope angle, slope aspect, elevation, distance from drainages, distance from roads, distance from main faults, seismic intensity and lithology were selected as controlling factors for earthquake-triggered landslide susceptibility mapping. Qualitative susceptibility analyses were carried out using the map overlaying techniques in GIS platform. The validation result showed a success rate of 82.751 % between the susceptibility probability index map and the location of the initial landslide inventory. The predictive rate of 86.930 % was obtained by comparing the additional landslide polygons and the landslide susceptibility probability index map. Both the success rate and the predictive rate show sufficient agreement between the landslide susceptibility map and the existing landslide data, and good predictive power for spatial prediction of the earthquake-triggered landslides.     

基于遥感影像的建筑抗震能力分析

据震害统计,房屋抗震能力是影响灾害的主要因素,抗震能力一般由房屋抗震设防水平、结构类型、建造年代和房屋层数等因素决定,通过对房屋抗震能力的综合评定,以便采取更有针对性的地震灾害对策。本文通过遥感影像实现房屋基本信息的快速提取,提高房屋结构类型获取的便捷性,具有较高的准确度和可靠度,并利用抽样调查得到张家口万全区房屋建造年代和层数分布特点,结合当地抗震设防水平,建立房屋抗震能力指数指标体系,阐述房屋抗震能力现状,为地震灾害损失评估、风险普查、风险区划等工作提供参考。     

Seabird aggregative patterns: A new tool for offshore wind energy risk assessment

The emerging development of offshore wind energy has raised public concern over its impact on seabird communities. There is a need for an adequate methodology to determine its potential impacts on seabirds. Environmental Impact Assessments (EIAs) are mostly relying on a succession of plain density maps without integrated interpretation of seabird spatio-temporal variability. Using Taylor’s power law coupled with mixed effect models, the spatio-temporal variability of species’ distributions can be synthesized in a measure of the aggregation levels of individuals over time and space. Applying the method to a seabird aerial survey in the Ebro Delta, NW Mediterranean Sea, we were able to make an explicit distinction between transitional and feeding areas to define and map the potential impacts of an offshore wind farm project. We use the Ebro Delta study case to discuss the advantages of potential impacts maps over density maps, as well as to illustrate how these potential impact maps can be applied to inform on concern levels, optimal EIA design and monitoring in the assessment of local offshore wind energy projects.     

2013年甘肃岷县漳县6.6级地震触发滑坡及其构造分析

2013年7月22日,甘肃省岷县漳县交界发生了Ms6.6地震.地震触发了大量的、类型各种各样的滑坡.滑坡类型以黄土崖崩、滑、倾为主,还有一些深层连贯型土质滑坡、大型土质流滑、斜坡裂缝等类型.地震滑坡主要分布在一个与临潭-宕昌断裂平行的长条形区域内.该长条形区域面积约为250km2,长度约40km,最大宽度约8km.对应不同构造段落的区域内滑坡发育程度不同,反映了不同段落发震构造的特征差异.滑坡的主体分布范围与震中位置表明了构造破裂是从SEE向NWW方向发展的.最后,分析了该滑坡主体分布区中心线与临潭-宕昌断裂在空间地理位置上相差10km的2种可能的原因.     

Reflection of hydrostatic mountain waves from spatially nonuniform layers

Abstract

The steady, hydrostatic, inviscid, Boussinesq flow of a stably stratified fluid over a bell-shaped ridge is investigated within the framework of a linear model. The three layer model atmosphere introduced is such that the Brunt-Väisälä frequency is constant in each layer but the interfaces of the middle layer are allowed to vary gently in the cross-ridge direction. In essence, the model can be tuned in both vertical and horizontal directions. These cross-ridge variations can produce significant differences in both the cross-ridge surface wind and the surface drag compared to the response obtained by use of a horizontally uniform reflecting layer. These changes are sensitive to both the vertical location of the middle layer and to the slope of its lower interface at the ridge crest. Many of these features are explained by means of a conventional layered-model analysis.     

SeaBat 8101型多波束测深系统在航道整治工程中的应用

基于作者从事航道测量的相关工作经验,介绍了SeaBat 8101型多波束测深系统构成与工作流程,详细探讨了其在乐天溪航道整治工程中的具体应用。     

基于可见性直方图的传递函数在心脏三维显示中的应用

在心脏的三维可视化的研究中,传递函数是一个十分重要的工具。然而,心脏复杂的结构使传递函数的设计十分困难。本文介绍了基于可见性直方图的传递函数设计以用来显示心脏双源CT数据。先对心脏双源CT体数据做预处理,提出在视线投射算法中利用基于可见性直方图的心脏传递函数对心脏数据进行三维显示,并且提出半自动方法来确定传递函数。通过这些方法,用户可以通过调节传递函数突出显示感兴趣的部分,甚至可以观察到心腔的许多细节。最后,利用CUDA技术对计算及显示进行加速,对三维体数据进行实时动态显示。实验表明,利用本文提出的方法可以有效地去掉心脏双源CT中的肋骨,肺静脉等数据,突出显示心肌组织及血液,并且通过传递函数可以看到主动脉瓣等心脏内部结构,对于心外科医生临床诊断有一定的意义。     

Resilience Theory and Thomas Vale's Plants and People: A Partial Consilience of Ecological and Geographic Concepts of Succession

Geography has discovered resilience theory, a body of thought about ecological change that initiated with C.S. Holling in the 1970s. We describe the similarities and differences between resilience theory and a geographical treatise, Thomas Vale's (1982) book Plants and People. Vale's work draws more from the tradition of field botany and plant succession than from the theoretical and mathematical ecology that prompted Holling's ideas. Yet like resilience theory, Vale's model of ecological change emphasized multiple states, the threshold transitions between them, and their irreversibility. Each described how forests and rangelands can flip between stability domains in response to altered fire regimes, modified grazing pressures, and climate change. Plants and People also recognized the dual nature of stability encapsulated in Holling's formalization of engineering and ecological resilience. Although resilience theory predates Vale's work and retains primacy through its citation record, we show how their partial consilience promotes a more critical understanding of resilience theory and the ways in which models, scale, and human values influence our comprehension of ecological change.