期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
河系树的建立及其应用 被引量:8
1
作者 张青年 全洪 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2005年第6期101-104,共4页
从树状河系的结构特点出发,提出了自河源开始向下游追踪,由河段数据构建河流实体、区分左右支流、自动建立河系树的方法,并将其用于河流数据的查询处理与数据质量检查。并在Java环境下编程试验了该方法,在河流检索及数据检查试验研究中... 从树状河系的结构特点出发,提出了自河源开始向下游追踪,由河段数据构建河流实体、区分左右支流、自动建立河系树的方法,并将其用于河流数据的查询处理与数据质量检查。并在Java环境下编程试验了该方法,在河流检索及数据检查试验研究中取得了满意的效果。 展开更多
关键词 状河流 河系树 数据检索 质量检查
下载PDF
基于图论河系树的河网综合
2
作者 张子刚 吴婧 《兰州工业高等专科学校学报》 2011年第6期17-20,共4页
研究了基于图论的由河段数据构建河流实体,建立河系树,并进行河网自动综合和显示的过程.详细介绍了河系树的建立过程,河流的流向、主流和支流的确定方法,在综合过程中应用综合指数的方法确定左右支流的过程等.
关键词 河系树 图论 符号化 地图综合
下载PDF
河网数据渐进式传输的自适应可视化研究 被引量:2
3
作者 杨军 石传奎 +1 位作者 闫浩文 程耀东 《测绘通报》 CSCD 北大核心 2013年第1期45-48,共4页
在构建河系树的基础上,结合河流层次、等级、数量密度和长度等河流描述因子,提出将河流选取数量按河流数量密度逐级分摊到河系与河系内部各级子流域的方法。选取的河流按其层次逐层输出可视化的试验表明,该方法是有效的。
关键词 渐进式传输 河系树 河流选取 自适应可视化
下载PDF
Tree-ring based PDSI reconstruction since 1853 AD in the source of the Fenhe River Basin,Shanxi Province,China 被引量:6
4
作者 SUN JunYan LIU Yu +1 位作者 SUN Bo WANG RuiYuan 《Science China Earth Sciences》 SCIE EI CAS 2012年第11期1847-1854,共8页
A robust tree-ring-width chronology was developed from two Pinus tabulaeformis sampling sites in the source of the Fenhe River,Shanxi Province,China.Based on the tree-ring-width indices,a 157-year long Palmer Drought ... A robust tree-ring-width chronology was developed from two Pinus tabulaeformis sampling sites in the source of the Fenhe River,Shanxi Province,China.Based on the tree-ring-width indices,a 157-year long Palmer Drought Severity Index(PDSI) was reconstructed,which explains 53.7% of the variance of the modeled PDSI over the common period 1957-2008.The drought periods in the study area include 1914-1931 and 1970 to the present,whereas the wet periods were 1866-1892 and 1932-1969.The drought of 1914-1931 was a severe long-lasting drought with a low inter-annual variability,and the drought of 1970-2009 was an overall long-term drought with a high inter-annual variability.The period of 1866-1892 is a continuously wet period with a low inter-annual variability and the period of 1932-1969 is an overall long-term wet period with a high inter-annual variability.The reconstructed PDSI series in the source of the Fenhe River shows synchronous variations with the regional drought/wetness indices.Spatial correlation analyses indicate that the higher correlations lie exclusively in the Fenhe River Basin.This indicates that the reconstructed PDSI has regional representativeness and can represent the drought history of the entire Fenhe River Basin to some extent.Furthermore,the reconstructed PDSI matches with the variability of the per unit yield of summer grain crops in Shanxi Province very well and they have significant correlation.From a long-term perspective the reconstructed PDSI series could supply scientific and valuable information to the water resources management and then help the sustainable development in agricultural production,economic development,and ecosystem balance. 展开更多
关键词 tree-ring-width indices PDSI reconstruction DROUGHT the Fenhe River Basin China
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部