植被波谱空间尺度效应及尺度转换方法初步研究

基于遥感图像的地物识别需要大量地物波谱数据的支持,而现有地物波谱库中收集到的同一地物的波谱,由于其测量尺度和方法的差异,波谱也存在很大差异.以冬小麦为例,首先介绍了材料波谱、端元波谱和像元波谱这3种不同尺度波谱的概念,并以实验数据分析了不同测量尺度下波谱的差别,以此说明波谱尺度转换的必要性.然后利用物理模型和统计模型建立不同测量尺度下的波谱转换关系.分别验证了SAILH模型和线性光谱混合模型在波谱转换中的精度.研究表明,在大尺度上采用统计模型,在小尺度上采用非线性的物理模型可以解释不同尺度观测植被波谱之间的差异.     

黑河流域水环境演变及其驱动机制研究进展

基于近几十年来诸多学者对西北干旱区典型内陆河流域——黑河流域水环境演变诸方面研究成果,综述了上游山区成水环境、中游绿洲用水环境和下游荒漠天然绿洲水成环境在不同时间尺度上的演变过程及其驱动机制。通过对各种古环境代用指标的对比研究表明：在大尺度上,流域上下游表现出阶段性的一致性水环境演变趋势;在小尺度上,则表现水环境演变的时空异质性。驱动机制方面,在空间上,流域上、中、下游水环境演变的气候变化和人类活动影响驱动作用各有侧重;在时间上,表现为不同尺度上气候变化与流域人类活动耦合作用的驱动机制。     

经验模式分解的尺度阈值滤波在变形分析中的应用

本文将信号处理领域的经验模式分解算法应用于变形信息的提取中,通过引入阈值函数,建立了基于经验模式分解的尺度阈值滤波模型,采用优化模型确定了经验模式分解的次数。分别通过模拟试验和实测数据与小波阈值法和多项式拟合法进行了比对,分析表明:在低噪声情况下,三种方法都有一定的滤波效果;在高噪声情况下,经验模式分解的尺度阈值滤波法具有与小波阈值去噪法相等的精度,而且瞬时强噪声识别能力更好,优于多项式拟合法。     

试论我国城市发展方针

在执行重重工业的发展战略和城乡分割体制的计划经济背景下,我国制定了“控制大城市规模,合理发展中等城市,积极发展小城市”的城市建设方针。但是分析表明,这一方针不能适应市场经济和对外开放形势的需要,也不符合我国人多地少、农村剩余劳动力多的国情,必须调整现有的城市发展方针,选择适宜的城市化发展道路。因此,本文就适度发展大中城市,提高城市现代化水平;加速乡村城市化,积极合理发展小城镇;以及根据不同地区的具体情况,因地制宜地指定城市化途径等方面作了探讨。     

山东省日照市蓝色经济区工程建设适宜性评价

本文以山东省日照市蓝色经济区为研究区, 通过野外地质调查和室内综合分析, 选取场地稳定性、工程地质条件、地下水条件, 地形排水条件、地质灾害及其他因素6个一级评价因子, 构造活动、场地土类型、建筑场地类别等13个二级评价因子, 利用专家-层次分析定权法进行区内工程建设适宜性评价, 得到了相应工程建设评价分区图。评价结果表明, 日照市场地工程建设适宜性总体较好, 大部分地区适宜进行高层建筑工程建设, 占84.50%; 地下空间开发利用条件优越, 全区多数地区属于城市地下空间建设适宜区, 适宜性差及不适宜区主要分布在付疃河两岸附近和海岸附近、大型高速公路和铁路沿线一带区域及城区; 轨道交通建设适宜性良好, 小部分不适宜区主要集中在付疃河下游夹仓和小古镇一带及其沿海地区。评价结果可有效地服务于该地区规划布局、建设发展和工程选址, 具有重要的理论和实践指导意义。     

Timing effects on the fragmentation of small scale blocks of granodiorite

A series of small scale tests, simulating multi-hole blasts have been performed to establish the effect of delays on blast fragmentation. The blasts were performed in high quality granodiorite blocks, which were cut from stone prepared by dimensional stone quarry operations. The pattern used was equilateral triangular, with a distance of 10.2 cm between boreholes, which had a diameter of 11 mm, were loaded with detonating cord and the coupling medium was water. The delays used were achieved using different lengths of detonating cord for the cases of delays between 0 and 100 μs between holes and a sequential blasting machine firing seismic detonators for larger delays up to 4 ms. All fragments were collected and screened. The experiments showed that the worst fragmentation was achieved with simultaneous initiation of all charges. Fragmentation improved with the delay time between holes up to 1 ms between holes. If the experiments are scaled up, the results show that in granodiorite, fragmentation optimization requires delays of few milliseconds per metre of burden. The findings, agree with previously published work, involving larger scale experiments and other rock types.     

Comparative Seismic Risk Studies for German Earthquake Regions on the Basis of the European Macroseismic Scale EMS-98

Within the framework of recent research projects, basic tools for GIS-based seismic risk assessment technologies were developed and applied to the building stock and regional particularities of German earthquake regions. Two study areas are investigated, being comparable by the level of seismic hazard and the hazard-consistent scenario events (related to mean return periods of 475, 2475 and 10000 years). Significant differences exist with respect to the number of inhabitants, the grade and extent of urbanisation, the quality and quantity of building inventory: the case study of Schmölln in Eastern Thuringia seems to be representative for the majority of smaller towns in Germany, the case study of Cologne (Köln) stands for larger cities. Due to the similarities of hazard and scenario intensities, the considerable differences do not only require proper decisions concerning the appropriate methods and acceptable efforts, they enable conclusions about future research strategies and needs for disaster reduction management. Not least important, results can sharpen the focus of public interest. Seismic risk maps are prepared for different scenario intensities recognising the scatter and uncertainties of site-dependent ground motion and also of the applied vulnerability functions. The paper illustrates the impact of model assumptions and the step-wise refinements of input variables like site conditions, building stock or vulnerability functions on the distribution of expected building damage within the study areas. Furthermore, and in contrast to common research strategies, results support the conclusion that in the case of stronger earthquakes the damage will be of higher concentration within smaller cities like Schmölln due to the site-amplification potential and/or the increased vulnerability of the building stock. The extent of damage will be pronounced by the large number of masonry buildings for which lower vulnerability classes have to be assigned. Due to the effect of deep sedimentary layers and the composition of building types, the urban centre of Cologne will be less affected by an earthquake of comparable intensity.     

Kaleidoscoping Landscapes,Shifting Perspectives

Landscapes change in complex ways, creating surface patterns reminiscent of forms seen through a kaleidoscope. On the Earth's surface, those forms are linked to, and caused by, processes that originate with bedrock‐soil‐vegetation‐atmosphere interactions. Human‐caused alterations to landscapes are additionally tied to socioeconomic processes. Evaluation of landscape‐level processes can benefit from examining (1) the influence of disturbance regimes in altering landscape patterns, (2) the importance of considering surficial processes, (3) the subtle and cryptic spatial relations that may be present, (4) the reciprocal relationships among local processes and regional consequences, (5) the increased likelihood of some land cover transitions compared to others, and (6) the special case of landscapes with long histories of human use. These are all examples of potential fruitful arenas for interactions and represent a path for expansion of landscape ecology through accommodation of a broad range of content covered by the international GIScience community.     

The place of individuals in the politics of scale

Conceptualizations and re-conceptualizations of scale have been powerful tools for explaining spatial processes that transcend traditionally-bounded territories. Examining the role of individuals within a politics of scale can do even more to explain multi-scalar conflicts. This paper does so by examining struggles over airport expansion in the US, showing how an understanding of the various roles of individuals in the politics of scale – as sites of multiple scales, as actors constituting other scales, and as scales in and of themselves – better explains multi-scalar conflicts and offers more opportunities for resolving them.     

The Earthquake Readiness Scale: The Development of a Valid and Reliable Unifactorial Measure

Preparedness is a key dependent variable in many studies examining people’s response to disasters such as earthquakes. A feature of many studies on this issue, however, is the lack of attention given to psychometric issues when constructing measures of preparedness. With regard to earthquake preparation, for example, many studies could be greatly improved by the use of a valid and reliable measure of preparedness. This research developed such a measure that assessed both low-level preparedness, such as having an emergency kit, and high-level preparedness, such as altering home structures to mitigate damage. Studies of Wellington (New Zealand) residents using two samples totalling n=652 showed that 23 items measuring these different aspects of earthquake preparation could be combined into a reliable, valid, unifactorial scale. This brief scale should have utility in multivariate studies of earthquake preparation, either as a dependent variable, where preparation is the outcome variable of primary interest, or as one of several independent variables, where preparation and other measures predict another outcome variable.