排序方式: 共有29条查询结果,搜索用时 296 毫秒
11.
Based on hydrological data observed at Lijin gauging station from 1950 to 2008, the temporal changes of water discharge and sediment load of the Yellow River into the sea were analyzed by the wavelet analysis, and their impacts on the estuary were investigated in different periods based on the measured coastline and bathymetry data. The results show that: (1) there were three significant periodicities, i.e. annual (0.5-1.0-year), internnual (3.0-6.5-year) and decadal (10.1-14.2-year), in the variations of water discharge and sedi- ment load into the sea, which might be related to the periodic variations of El Nino and Southern Oscillation at long-term timescales. Variations of water discharge and sediment load were varying in various timescales, and their periodic variations were not significant during the 1970s-2000s due to strong human disturbances. (2) The long-term variation of water discharge and sediment load into the sea has shown a stepwise decrease since the 1950s due to the combined influences of human activities and precipitation decrease in the Yellow River Basin, and the human activities were the main cause for the decrease of water discharge and sediment load. (3) The water discharge and sediment load into the sea greatly influenced the evolution of the Yellow River Estuary, especially the stretch rate of coastline and the deposition rate of the sub-aqueous topography off the estuary which deposited since 1976. 相似文献
12.
黄河三角洲岸线及现行河口区水下地形演变 总被引:2,自引:0,他引:2
根据实测的岸线和水深数据,利用Surfer 和Mapinfo 等软件进行数据处理,结合不同阶段利津站输沙量,分析了黄河三角洲岸线及现行河口区水下地形演变。结果表明:1953-2000年,68%左右的入海泥沙淤积在口门和滨海区。由于入海流路变迁,不同岸段的岸线变化具有各自的特征。刁口河流路以西岸线基本稳定;刁口河流路以东—孤东油田以北岸线经历先淤后冲,属于强侵蚀岸段,但在防潮大堤的保护下得到人为控制下的稳定;清水沟流路形成的岸线整体向海淤进,但清8 出汊后,清水沟老河口沙嘴南侧出现侵蚀。1976-1996 年,现行河口(清水沟流路) 水下地形总体上表现为淤积,顶坡段变缓,前坡段变陡。1996-2005 年,清水沟老河口水下地形顶坡段和前坡段发生侵蚀,底坡段呈现淤积;出汊新河口水下地形继续淤积,但程度和范围都比1976-1996 年的小。孤东油田近岸侵蚀加剧。 相似文献
13.
14.
15.
16.
莱州湾南岸浅层地下水特征的空间变异性研究 总被引:1,自引:0,他引:1
以整个莱州湾南岸区域作为研究对象,运用经典统计学和地统计学相结合的方法研究了该区2007-2009年浅层地下水埋深及矿化度的空间变异特征,并绘制了其空间分布图.结果表明:地下水矿化度和埋深在东西和南北两个方向都呈二阶趋势效应,具有强的空间自相关性,说明主要受自然因素影响;kriging插值表明:离海岸线距离越近地下水矿化度越大,地下水埋深表现为西南部较深,而东南部和西北部较浅,地质构造、河流及海水入侵等自然因素作用是形成该空间格局的重要因素.地下水特征的空间结构性和定量化研究对莱州湾南岸地区地下水资源评价和区域水盐迁移调控有着直接的现实意义. 相似文献
17.
文章运用地统计学的方法对山东滨海盐渍土年际空间变异和分布特征差异进行分析研究,结果表明:黄河三角洲表层土壤的盐渍化程度较高且在年际变化上呈积盐趋势,莱州湾南岸则呈脱盐趋势但盐渍化面积增加;山东滨海低平原区盐渍土受结构因素的影响加剧;表层土壤盐分的分布规律与地形有密切关系,盐渍化类型与盐渍化程度的分布特征基本吻合;莱州湾南岸应注意防止土壤碱化。由此提出因地制宜综合开发、减少土壤盐分输入、加强盐分淋洗、改善土体性质和防止土地碱化等建议,对滨海地区后备土地水土资源的开发利用具有指导作用。 相似文献
18.
19.
1950-2008年黄河入海水沙变化(英文) 总被引:1,自引:0,他引:1
Based on hydrological data observed at Lijin gauging station from 1950 to 2008, the temporal changes of water discharge and sediment load of the Yellow River into the sea were analyzed by the wavelet analysis, and their impacts on the estuary were investigated in different periods based on the measured coastline and bathymetry data. The results show that: (1) there were three significant periodicities, i.e. annual (0.5-1.0-year), internnual (3.0-6.5-year) and decadal (10.1-14.2-year), in the variations of w... 相似文献
20.
近60 年黄河入海水沙多尺度变化及其对河口的影响 总被引:9,自引:0,他引:9
基于1950-2008 年利津站月均径流量和输沙量的时间序列资料,采用小波分析的方法研究了黄河入海水沙多尺度变化,并结合不同年份的黄河口岸线和口门地形资料分析了水沙变化对河口演变的影响。结果表明:黄河入海水沙具有3 个不同时间尺度的显著周期变化,其与厄尔尼诺事件有关,不同尺度下的入海水沙丰枯变化不同;受流域降水和人类活动的影响,入海水沙长期呈减少趋势,并具有阶段变化的特征;入海水沙变化深刻影响着河口演变,不同时期行水河口的岸线延伸速率与河口来沙量有关,亿t 泥沙岸线延伸量与来沙系数显著相关,自1976 年清水沟流路入海以来,河口水下三角洲表现为淤积,淤积程度与入海水沙量密切相关。 相似文献