Multi-designated geoparks face challenges in China’s heritage conservation     

WANG Lianyong 《地理学报》2007,17(2):187-196

The author selects a thorny issue of doubled designations that bother pol-icy-makers, professional planners and managers in the field of conservation for protected areas. The analyzed case study areas cover 5 National Geoparks of China in Sichuan Prov-ince, 18 UNESCO Global Geoparks in China, and 219 World Heritage sites in China and 8 European nations. Through analysis and synthesis, the author concludes that doubled des-ignation, which also leads to unbalanced park distribution, is particularly prevalent in China other than in Europe. Therefore, on-site management agencies and related governments in China should carefully translate the doubled designations into responsibilities and harmoni-ous partnerships between all stakeholders in order to enhance the management effectiveness and avoid paper park phenomenon.  相似文献   

From the kitchen and the field: Gender and maize diversity in the Bajío region of Mexico     

Kimberlee J. Chambers  Janet Henshall Momsen 《Singapore journal of tropical geography》2007,28(1):39-56

The conservation of crop genetic diversity in farmers' fields is important for future food security. Recent research on women and biodiversity has emphasized the importance of women's knowledge in plant domestication and biodiversity conservation. This paper presents a case study of the differences in women's and men's knowledge of maize landraces in four different environments in the Bajío region of Mexico. We argue that research on crop diversity and conservation needs to include both men and women farmers' knowledge. Gendered knowledge results from men and women in a household being responsible for different tasks and sometimes for farming separate plots. In addition, as economic pressures increasingly force men to work away from their communities for extended periods, women become the primary agricultural decision-makers.  相似文献   

Artificial screen for reducing seismic vibration generated by blasting     

Dragan Bogunovic  Vladislav Kecojevic 《Environmental Geology》2007,53(3):517-525

The purpose of blasting operations is rock fragmentation. Blasting is a key component in the overall rock fragmentation system - the first element of the ore extraction process. It provides appropriate rock material granulation or size that is suitable for loading and transportation. However, in spite of many advantages explosives have, their usage may cause environmental problem such as seismic vibration. One of the solutions to this particular problem may be application of an artificial screen as a barrier to the seismic wave path. The results of experimental research on the artificial screen concept, its characteristics and role in attenuation of seismic effects generated by blasting are presented. The experiment is based on two physical phenomena: (1) the size and degree of discontinuity and (2) the reflection and refraction of seismic waves. More than 1,500 laboratory measurements were conducted with different combinations of screen sizes, positions of the screen to blasting source, and intensities of blasting impulses. The results of the study show reduction of generated vibrations up to 58% by employment of artificial screens.  相似文献   

Scaling Laws and Experimental Modelling of Contaminant Transport Mechanism through Soils in a Geotechnical Centrifuge     

P. R. Kumar 《Geotechnical and Geological Engineering》2007,25(5):581-590

This paper presents the results of a research program conducted on the geotechnical centrifuge to investigate contaminant transport mechanism through the soil mass. The mechanism that governs contaminant transport through soil mass is discussed, the principles of geotechnical centrifuge modelling are outlined, and relevant scaling laws that govern the relationship between a centrifuge model and the prototype, with respect to the problem of contaminant transport, are presented. Modelling of models has been established to validate the experimental results. It has been concluded that the geotechnical centrifuge can be used as an experimental tool to simulate field scale problems.  相似文献   

THE DISTRIBUTION OF PREFERENTIAL PATHS AND ITS RELATION TO THE SOIL CHARACTERISTICS IN THE THREE GORGES AREA, CHINA   总被引：1，自引：0，他引：1  

Hongjiang ZHANG Jinhua CHENG Yuhu SHI Yun CHENG 《国际泥沙研究》2007,22(1):39-48

To study the characteristics of the distribution of the preferential paths and the affecting factors in the Three Gorges area, four soil profiles were dug to observe the distribution of preferential paths in the Quxi watershed in the Yangtze River basin. The Morisita exponential test method was used to examine the distribution type of preferential paths. The physical properties and infiltration characteristics of the soil were also measured to evaluate their relationship to preferential paths. The results showed that in this area, preferential paths clustered and mainly distributed in the 80-100 cm soil layer, and along the interface between the weathered layer and semi-weathered layer. There were more non-capillary pores in the 83-110 cm layer than in the other layers. It can be derived that most non-capillary pores in this layer were preferential paths caused by geological processes and rotten plant roots. The percentage of coarse soil particles increased with the depth of the soil layer. In the deeper soil layer, the coarse soil particles helped the formation of preferential paths. The fastest steady infiltration rate was observed in the of 83-110cm layer, which is inferred to be due to the greater number of preferential paths.  相似文献   

A semi-implicit semi-Lagrangian global nonhydrostatic model and the polar discretization scheme   总被引：2，自引：0，他引：2  

YANG XueSheng  CHEN JiaBin  HU JiangLin  CHEN DeHui  SHEN XueShun  ZHANG HongLiang State Key Laboratory of Severe Weather  Chinese Academy of Meteorological Sciences  Beijing  China  State Key Laboratory of Numerical Modeling for Atmospheric Sciences  Geophysical Fluid Dynamics  Institute of Atmospheric Physics  Beijing  China 《中国科学D辑(英文版)》2007,50(12):1885-1891

The Global/Regional Assimilation and PrEdiction System(GRAPES) is a newly developed global non-hydrostatic numerical prediction model,which will become the next generation medium-range opera-tional model at China Meteorological Administration(CMA).The dynamic framework of GRAPES is featuring with fully compressible equations,nonhydrostatic or hydrostatic optionally,two-level time semi-Lagrangian and semi-implicit time integration,Charney-Phillips vertical staggering,and complex three-dimensional pre-conditioned Helmholtz solver,etc.Concerning the singularity of horizontal momentum equations at the poles,the polar discretization schemes are described,which include adoption of Arakawa C horizontal grid with ν at poles,incorporation of polar filtering to maintain the computational stability,the correction to Helmholtz equation near the poles,as well as the treatment of semi-Lagrangian interpolation to improve the departure point accuracy,etc.The balanced flow tests validate the rationality of the treatment of semi-Lagrangian departure point calculation and the polar discretization during long time integration.Held and Suarez tests show that the conservation proper-ties of GRAPES model are quite good.  相似文献   

暴雨落区的统计与分析研究   总被引：4，自引：5，他引：4       下载免费PDF全文

任敏  郝莹  陈焱 《气象科学》2007,27(2):214-219

用34 a的降水资料对安徽省4—9月暴雨落区进行了统计分析,结果表明安徽暴雨主要集中在6月到7月,暴雨日数多寡和暴雨范围大小,基本决定了汛期降水多少和旱涝趋势。汛期暴雨落区集中出现在582—584 dagpm的500 hPa等压面斜坡上,因此暴雨带的位置预报大致可以用584 dagpm线的移动作参考。并用2003年梅雨期20场暴雨与一些实况物理量场进行对比,得出西风急流北侧以及500 hPa上升运动中心南侧到850 hPa上升运动中心北侧,有利于暴雨发生发展。  相似文献   

信息系统安全外联接入平台初探     

王建法  谢朝海 《国土资源信息化》2007,(4):44-46

根据信息系统内外网络业务数据交换的需要,本文提出一种基于主动数据交换的安全外联接入平台。安全外联接入平台不但具有安全的网络物理隔离功能,而且能提供一系列安全服务认证、授权、安全审计、入侵检测和病毒防范等。  相似文献   

改进APEX算法在图像增强中的应用     

孙雷  张艳  徐青  张春美 《测绘学院学报》2007,(1)

APEX是一种基于快速傅立叶变换的直接盲解卷积算法,能够快速复原复杂纹理图像。该算法适用于平移不变且以2维放射对称Le’vy Stable概率密度函数(G类点扩散函数)作为卷积核的图像。论述了A-PEX算法的原理,并针对APEX在适应性和稳定性方面的不足提出了改进方法。实验表明,改进的APEX算法能够有效应用在多种真实模糊图像上,增强图像对比度和锐化图像细节,使图像的视觉效果得到明显改善。  相似文献   

Towards a gender conscious counter-discourse in comprehensive physical planning     

Tora Friberg 《GeoJournal》2006,65(4):275-285

This article is based on a research project “Gender perspectives in comprehensive planning” where the aim is partly to ascertain how planners incorporate a gender perspective in comprehensive physical planning, and partly to identify the conceptions of gender/sex held by planners in this area. In our investigation, the question is raised whether comprehensive planning is perceived as neutral in terms of gender, if there are discussions or reflections that question this point of view and if there have been any contributions from a gender equality point of view. The aim is to expose how these discussions take place, examine reflections on this topic and to report and analyse how efforts to achieve gender equality in comprehenisve planning are shaped. To accomplish this goal, the study draws more on feminist theorization than on planning theory.  相似文献