期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
索引顺序文件初探 被引量:1
1
作者 贺玲勇 《现代图书情报技术》 1981年第4期10-16,共7页
关键词 索引顺序文件 记录键 磁道索引 溢出 主数据区 指示字 记录信息 柱面索引 溢出记录 倒排文件
下载PDF
Dynamic analysis of mainstream area and vegetation coverage degree of Songhua River based on RS and GIS techniques
2
作者 CHANG Cheng ZHANG Yuanqing ZHU Cong 《Global Geology》 2012年第1期66-73,共8页
Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action... Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action method.The results show that the area of Songhua River mainstream was 738 102 km 2 in 1990,and was 810.451 km 2 in 2000.From 1990 to 2000,the increased area of river mainstream is up to 72.349 km2 due to soil erosion and water loss.Meanwhile,the dynamic changes of surrounding vegetation cover are also studied.It is estimated that the trend of surrounding soil erosion and water loss of Songhua River mainstream becomes worse in Jilin Province. 展开更多
关键词 water loss and soil erosion vegetation cover RS GIS Songhua River mainstream
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部