首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   255篇
  免费   5篇
  国内免费   2篇
测绘学   32篇
大气科学   10篇
地球物理   8篇
地质学   36篇
海洋学   16篇
综合类   11篇
自然地理   149篇
  2023年   3篇
  2022年   11篇
  2021年   8篇
  2020年   12篇
  2019年   20篇
  2018年   8篇
  2017年   17篇
  2016年   11篇
  2015年   8篇
  2014年   8篇
  2013年   32篇
  2012年   14篇
  2011年   7篇
  2010年   4篇
  2009年   3篇
  2008年   11篇
  2007年   9篇
  2006年   7篇
  2005年   11篇
  2004年   5篇
  2003年   8篇
  2002年   10篇
  2001年   6篇
  2000年   8篇
  1999年   5篇
  1998年   1篇
  1997年   2篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   4篇
  1983年   1篇
排序方式: 共有262条查询结果,搜索用时 15 毫秒
191.
规则格网DEM是DEM的主要表示方式,应用最为广泛,影响DEM质量的关键因素便是内插过程,包括内插精度和效率两个方面。现有的诸多规则格网DEM内插方法基本都不能兼顾内插精度和效率,很大程度上制约了DEM的生产。本文在分析已有方法的基础上,提出了基于Delaunay冲突区域搜索策略的TIN内插规则格网DEM方法,并以实验对该方法进行验证和分析。实验结果表明文中所提方法对规则格网DEM内插精度与效率行之有效。  相似文献   
192.
基于可持续性视角的建设用地适宜性评价及其应用   总被引:1,自引:0,他引:1  
建设用地适宜性是土地资源利用与管理决策的依据。本文基于土地利用可持续性界定建设用地适宜性内涵,从灾害风险、地形地貌、生态环境和区位条件4个维度,构建了较规范的适宜性指标体系;针对已有评价方法的不足,构建了整合极值法、条件函数法、线性加权综合的“多要素分布式算法——情景矩阵”评估框架;进而基于适宜性识别冲突空间,以空间冲突面积占总建设用地面积的比重作为空间冲突强度来刻画区域建设空间布局的合理性与可持续性。本文以新疆玛纳斯县为例开展研究,结果表明玛纳斯县适宜建设空间(达230 km2以上)约占全县总面积的26%;最适宜和比较适宜性建设用地主要分布于中部及中北部乡镇及农(团)场驻地附近,基本适宜建设区主要分布在比较适宜建设空间的外围及中南部山前平原地带;该县冲突空间达4.21 km2,占建成区面积的22.74‰;冲突空间主要分布在河流沿岸和中部城镇化发展区;南部、北部的生态脆弱区及中部工业化发展区的乡镇空间冲突强度也较高。研究表明,本文提出的建设用地适宜性评估框架与方法逼近客观现实,简单易行,能弥补以往评价方法的不足;适宜性在空间冲突分析与可持续性土地利用管理中具有较好的应用价值。  相似文献   
193.
相比于正交T-Snake算法,传统Balloon Snake算法不受格网约束,能够更加精确提取高分辨率遥感影像上水体,然而尚不能解决河中岛引起的拓扑冲突问题。由此,本文提出了一种改进Balloon Snake算法(T-Balloon Snake),设计了目标内部由于空洞引起的拓扑冲突检测与处理机制。算法首先在目标水体内部手动设置一个初始轮廓,在曲线每次膨胀前对曲线进行自相交检测,若存在拓扑冲突则对曲线进行分裂与合并处理,最终直至迭代停止。实验选取了三类湖泊与河流高分影像,实现了复杂遥感影像水体矢量边界的一次性精确提取。实验结果表明,该方法可直接有效提取水体中深凹以及岛状边界,在提取结果正确性和完整性上都优于传统Balloon Snake算法。  相似文献   
194.
C. Gdaniec 《GeoJournal》2000,50(4):379-387
In a former industrial part of Barcelona, as in the de-industrialising neighbourhoods of many big cities, the ‘new’ economy and the ‘cultural’ economy have started to replace the ‘old’ economy, bringing new life into a declining district but also causing conflicts of land use, housing or the preservation of architectural heritage. The latter is an important part of regeneration and marketing policies of city governments, whereby the ‘new’ economy not only emerges from the old but the physical space of the old industrial quarter becomes the tool and setting in which the city can re-present itself and its success story of transformation and regeneration. Through the increasing use of information and communication technologies, which are at the same time driving this transformation - an industry as such as well as business-aid in various sectors, cultural industries in particular - the city has acquired a second, virtual presence. The city exists and ‘lives’ on numerous websites. Those by city government and city organisations often have the express purpose of marketing and presenting the city, while those by (cultural) businesses and other organisations in the district add to the mosaic of the virtual city. As a result, the old industrial space continues to live and be productive, its economic value having changed largely into a cultural value. This coexistence of the real and the virtual, old and new, also meets with a conflict at certain junctures. There is the positive representation of plans and events on the city's websites on the one hand, and the undercurrent of protest and disenchantment among the local population who find themselves marginalised from the profits and success of development, on the other. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
195.
云南自然保护区与周边社区冲突的形式与原因分析   总被引:1,自引:0,他引:1  
在概括了云南省自然保护区与周边社区的冲突形式后,深入分析了冲突的深层次原因,认为云南省自然保护区大多设立在少数民族集聚的偏远山区,当地居民生活水平低下,生产生活严重依赖当地的自然环境和自然资源,保护区的建立打断了居民与环境的紧密联系,使得社区居民生存空间狭小,生活水平下降,丧失部分发展机会,在保护区建设和开发中得不到利益分配。基本结论是冲突和矛盾的解决必须基于体制的改善,必须充分考虑保护区周边社区居民的基本权益。最后针对云南省的情况提出一些改善意见。  相似文献   
196.
197.
地图数据库图形输出中要素关系处理   总被引:3,自引:2,他引:3  
刘纪平 《测绘学报》1994,23(3):222-228
本文提出了利用地图数据库的检索功能,建立要素图形输出的定量优先级、地理要素图形大小,及基于地图数据库的图形冲突位置的探测方法,并将要素图形输出中的关系划分为五种进行分别处理。  相似文献   
198.
We examine environmental aspects of the conflict between the Turkish state and the insurgent Kurdistan Workers Party (Partiya Karkerên Kurdistan or PKK). Since the early 1990s, several civil society groups have claimed that the Turkish army burned forests and destroyed other livelihood resources in the Kurdistan region of Turkey as it evacuated settlements. We report the results of a case study of destruction in Tunceli, eastern Turkey, undertaken in order to evaluate support for such claims. We demonstrate the use of geospatial techniques in case-specific approaches to the study of armed conflict. Through the analysis of satellite images, we verified eyewitness reports and confirmed that substantial burnings did indeed take place in the study area between 1991 and 1994. We argue that this destruction was not irrational or wanton, but that it was part of a strategy used by the Turkish army in the early 1990s that aimed at actively transforming the war environment.  相似文献   
199.
Monica V. Ogra   《Geoforum》2008,39(3):1408-1422
Human–wildlife conflict (HWC) is a growing problem for communities located at the borders of protected areas. Such conflicts commonly take place as crop-raiding events and as attack by wild animals, among other forms. This paper uses a feminist political ecology approach to examine these two problems in an agricultural village located at the border of Rajaji National Park in Uttarakhand (formerly Uttaranchal), India. Specifically, it investigates the following three questions: What are the “visible” and “hidden” costs of such conflict with wildlife? To what extent are these costs differentially borne by men and women? How do villagers perceive any such differences? Survey and interview data were collected from over 100 individuals in the study site over a period of 9 months in 2003–2004. It was found that for participants in this study, costs of HWC included decreased food security, changes to workload, decreased physical and psychological wellbeing, economic hardship, and at times an increase in illegal or dangerous activities. The research also showed that although women in the study area bore a disproportionate burden of these effects, roughly half of survey respondents perceived that men and women were equally affected. A possible explanation for this gap considers the relationships between gendered uses of space, work, status, and identity. The findings illustrate the importance of addressing both visible and hidden costs of HWC for members of park communities and support a call for increased gender-sensitivity in HWC research.  相似文献   
200.
Qualitative methods are important to gain a deep understanding of complex problems and poorly researched areas. They can be particularly useful to help explain underlying conservation problems. However, the significance in choosing and justifying appropriate methodological frameworks in conservation studies should be given more attention to ensure data are collected and analysed appropriately. We explain when, why, and how qualitative methods should be used and explain sampling strategies in qualitative studies. To improve familiarity with qualitative methods among natural scientists, we recommend expanding training in social sciences and increasing collaboration with social scientists. Given the scale of human impacts on the environment, this type of nuanced analytical skill is critical for progressing biodiversity conservation efforts.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号