CONCEPTUALIZING SMALL TOWNS AS URBAN PLACES: THE PROCESS OF DOWNTOWN REDEVELOPMENT IN GALENA,ILLINOIS

This research investigates the process through which small-town central business districts (CBDs) are transformed into visitor-oriented attractions. A case study of Galena, Illinois, reveals that the dominant characteristics of the downtown redevelopment process are applicable to metropolis and small town alike. Similar economic “tools,” enabling legislation, and other mechanisms are available to essentially all municipalities regardless of size. Further, growth coalitions and interest groups are formed to promote the particular use and exchange values of CBDs throughout the urban hierarchy. What differs between small town and large metropolis, however, is the way in which contemporary CBDs are perceived by the community. While the metropolitan downtown is now largely viewed as a “command center” within a global economy, the small-town CBD is still varyingly perceived as the community's economic and social center. Such contrasting conceptions of downtown hold implications for the ability to successfully transform Main Street into a tourist attraction without generating substantial inter-community conflict. [Key words: small town, historic district, main street, downtown redevelopment, tourism.]     

水生态屏障适宜宽度界定研究进展

在总结水生态屏障研究历程的基础上,对水生态屏障的概念进行了探讨,提出了水生态屏障的定义。从河流、湖泊、水库3种主要水生态屏障类型说明水生态屏障的主要功能及适宜宽度研究进展,并从生态学、水文学、地理学、遥感学的技术应用评述了水生态屏障宽度的界定方法。目前,对水生态屏障适宜宽度的标准还缺乏统一的认识,流域尺度下水库生态屏障适宜宽度的界定是水生态屏障宽度界定面临的难点问题,提出综合水文学、生态学、环境科学及地形、遥感、地理信息等多学科理论及技术手段构建流域尺度的生态水文模型是界定水生态屏障及其水库生态屏障适宜宽度的有效方法。     

甘肃内陆河流域生态功能及保护对策

从阐述张掖生态功能的重要意义入手,阐明了祁连山森林、湿地、人工绿洲成板块结构镶嵌分布,组成了强大的生态屏障,阻止了沙漠化的进程。针对张掖生态安全屏障保护存在的主要问题和甘肃祁连山国家自然保护区及张掖黑河湿地国家自然保护区建设现状,提出了祁连山自然保护区生态保护与管理及湿地国家级自然保护区生态恢复与综合治理的具体措施,为甘肃内陆河流域生态安全屏障建设提供参考依据。     

浅埋人防隧洞围岩加固处理技术及分析

根据埋深为6～13 m的某浅埋人防隧洞的前期稳定性分析,提出了对该人防隧洞选取灌浆加固处理方法。在工程的具体实施中,进行了两种浆液的配比实验,并分别确定了该人防隧洞在积水段和无积水段的加固材料及其配比。依据工程实际制定了灌浆施工工序,确立了浆液扩散半径以及3套灌浆终止条件。由灌浆扩散半径及岩芯强度测试的工程灌浆效果检验得知,此次加固措施完全达到了预期的效果和目的。     

防护林对沙尘阻滞作用的机理分析──建立微分方程的动态模型

在中国北方干旱一半干旱区,防护林对阻止沙漠化的推进和防止生态环境恶化起了重要的作用。文章试图通过建立微分方程动态模型的方法讨论防护林对风沙扬尘阻滞作用的机理,在对模型进行分析的基础上,进一步说明营建防护林的理论与实践意义。     

基于SRTM地形数据天气雷达地形遮挡分析系统开发及应用

天气雷达是目前对强对流、台风、暴雨等天气过程进行精细探测的重要手段之一,其观测数据对天气预报业务起着关键的作用.天气雷达的探测能力会受到雷达所建位置四周地形遮挡影响.因此合理的雷达选址能更大程度地发挥出雷达的探测能力.基于中国科学院计算机网络信息中心地理空间数据云平台获取的SRTM地形数据,利用MATLAB工具开发天气...     

Characteristics of Habitats Used by Enteroctopus dofleini in Prince William Sound and Cook Inlet,Alaska

Abstract. Habitat characteristics associated with the giant Pacific octopus, Enteroctopus dofleini (Wülker 1910), were studied in Prince William Sound and Port Graham, Alaska, from beach walk, SCUBA and submersible surveys at depths of 0 to 197 m. Octopus counts on beach walk transects were positively correlated with soft substrates (sand, gravel or broken rubble), the presence of boulders, and dense kelp cover immediately offshore of the transect; and negatively correlated with depth on SCUBA transects. No significant habitat correlations were found with counts on submersible transects. On beach walks, octopus counts were reduced on hard substrates to 38 % of the counts on soft substrates. Counts increased five‐fold in the presence of boulders over counts in their absence, and increased fifteen‐fold adjacent to dense (> 75 %) kelp cover over counts adjacent to sparse (< 25 %) kelp cover. On SCUBA transects, the average density at less than 5 m depth was over five times that below 5 m. No trends in octopus size or sex ratio were detected with depth. Den use was inversely correlated with depth although there was no indication that den availability declined with depth. Octopuses were found at densities from 0 to 2.5 per 1000 m². These densities were only 1 to 50 % of densities of the same species recorded in British Columbia in the late 1970s and early 1980s. Few data are available to test recruitment, mortality, and habitat selection hypotheses that would account for differences between habitats. However, the presence of the highest octopus densities in intertidal and very shallow subtidal areas indicates the likely importance of near‐shore, shallow‐water habitats, and highlights the vulnerability of octopus populations to changes in these habitats.     

基于GIS的安庆市应急避难场所空间布局特征分析与优化

随着城市发展步伐的加快,火灾、爆炸、公共卫生事故、工程事故等人为灾害性事件频发,洪水、地震、台风等自然灾害也给城市居民的生命和财产安全造成了极大损失。由于城市规模和人口数量将越来越大,城市应急避难场所在城市规划中就显得更加重要。本文以安庆城区为例,根据城市人口分布状况以及城市总体的空间布局,分析应急避难场所的特征及其与城市的适应程度。采用GIS的空间查询、网络分析、最佳路径分析等功能,检验该市应急避难场所的合理性。针对城市规划中应急避难场所空间布局上不合理的问题,进行方案优化。研究结果将给安庆市应急避难场所的空间布局带来一定的借鉴作用。     

The catastrophic cyclone of April 1991: Its Impact on the economy of Bangladesh

A very severe cyclonic storm with wind speeds of over 240 km/h struck the coastal areas of Bangladesh in the full moon night of 29 April 1991. The path of the eye, close to the shore, raised a storm surge of unusual height, reportedly more than 9 m above the mean sea level, which devastated the offshore islands and the mainland coast. The damage to the physical infrastructure of the port of Chittagong and adjoining industrial area has been colossal, and recovery will take years. Death tolls from the cyclone, storm surge and its aftermath exceeded 145 000 making it one of the world's major natural disasters of this century.This paper is concerned with examining the magnitude and intensity of the disaster. It analyses how the people of Bangladesh, and the environment in which they live, were affected by the cyclone. A brief account is presented of loss of life and of the damage suffered in various sectors, including agriculture, industry, and physical infrastructure.The paper lays emphasis on the need of building a sufficient number of multipurpose cyclone shelters in the disaster-prone coastal areas of Bangladesh. Adequate measures should be taken for evacuating people from vulnerable areas and putting them into these shelters in the event of a cyclonic storm. Simplification of the current cyclone warning system is recommended.The difficulties of providing relief to the survivors are discussed. And finally, the need for improvement of the communication infrastructure in the coastal areas is highlighted.     

一种野外测量方舱及其设计

本文介绍了一种用于野外测量的综合保障方舱及其设计，侧重介绍了泫方舱的基本组成、功能和设计特点。论述了几个关键部件的设计思想和实现方案。最后简要说明了本方舱的两个辅助系统。该方舱适合在艰苦环境，特别是在无人区使用。经使用表明，该方舱满足野外测量保障的需要，结构紧凑，性能可靠。