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   40篇
  免费   1篇
测绘学   1篇
大气科学   5篇
地球物理   10篇
地质学   11篇
海洋学   7篇
天文学   2篇
自然地理   5篇
  2021年   4篇
  2020年   1篇
  2017年   1篇
  2014年   1篇
  2013年   3篇
  2011年   3篇
  2010年   3篇
  2008年   5篇
  2007年   1篇
  2006年   2篇
  2005年   1篇
  2003年   2篇
  2001年   3篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1991年   1篇
  1990年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
排序方式: 共有41条查询结果,搜索用时 0 毫秒
41.
In this study, historical landscape dynamics were investigated to (i) map the land use/cover types for the years 1972, 1987, 2000 and 2014; (ii) determine the types and processes of landscape dynamics; and (iii) assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies (and Kappa statistics) were of 68.86% (0.63), 91.32% (0.79), 90.66% (0.88) and 91.88% (0.89) for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of–2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation.  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