全文获取类型
收费全文 | 93篇 |
免费 | 21篇 |
国内免费 | 26篇 |
专业分类
测绘学 | 11篇 |
大气科学 | 51篇 |
地球物理 | 8篇 |
地质学 | 18篇 |
海洋学 | 8篇 |
综合类 | 15篇 |
自然地理 | 29篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 12篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
排序方式: 共有140条查询结果,搜索用时 78 毫秒
61.
62.
洪湖湿地抗渍蓄洪能力分析 总被引:3,自引:0,他引:3
鉴于洪湖湿地为渍涝灾害的多发区,并在江汉平原具有一定的代表意义,本文以该区为研究对象,利用遥感和地理信息系统技术进行分析,以便正确认识洪湖湿地的抗渍蓄洪能力.建立洪湖湿地的TIN模型以分析该区的抗渍蓄洪能力,并分别计算出洪湖湖泊的调蓄能力和整个洪湖湿地水位同蓄水面积及蓄水容量之间的关系.通过TIN模型与2001年的LandSat-ETM+遥感图像的叠加分析,统计出不同湿地类型的平均高程.依此计算出23. Ini高程线为水稻田的耕作线,由此推算出水稻基本不受影响条件下洪湖湿地的调蓄容量为1.087×109 m3.并提出在该区建立基于地理信息系统的减灾决策体系的建议,以便进行有效的防灾减灾. 相似文献
63.
Assessment of waterlogging risk in Lixiahe region of Jiangsu Province based on AVHRR and MODIS image 总被引:3,自引:0,他引:3
Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on waterlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1 km× 1 km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin. 相似文献
64.
THE STUDIES ON WATERLOGGING DAMAGE IN JIANGHAN PLAIN USING DEM 总被引:3,自引:0,他引:3
喻光明 《中国地理科学(英文版)》1992,2(1):87-93
The waterlogging damage is the pit to agriculture in plain and lake region. This damage is related to the groundwater, ancient lakes, soil, land use and negative landforms, the conventional technique is adopted to the study of this damage. In this paper, we suggest a new technical method, the technique is based on DEM, to study this problem. The DEM is developed on the ECLIPSE MV/ 10000 AOS/ VS system, and the estimation model of waterlogging loss is built on the historical data of the test region in Jianghan Plain. and then, the rice waterlogging loss of test region is estimated by them. 相似文献
65.
川江流域洪涝频繁而危害大。兹以旬、两旬雨量分别为250—350,350—500毫米作主要洪涝指标。流域内洪涝频率、大面积洪涝频率的分布区域差异明显。洪涝的形成受暴雨和大地形结构控制,此外还受四川盆地地形、水系结构与森林遭破坏等的影响。 相似文献
66.
REN Hongzun TANG DengyinInstitute of Geography Chinese Academy of Sciences Beijing CHINA 《地理学报(英文版)》1998,(2)
Mechanismforcontrolingdroughtandsalinity/waterlogginginNorthwestShandongProvinceRENHongzunTANGDengyinInstituteofGeography,Ch... 相似文献
67.
This paper investigates the interplay of the hydrogeological characteristics, soil properties and recent land reclamation projects on the distribution of waterlogging and salinization within the Farafra Oasis. The multi‐temporal remote sensing data and field observations show that new reclaimed areas have been recently cultivated in distant areas from the old agricultural land. These new cultivations have developed widespread waterlogging, seepage channels and soil salinization. Analyses of the Shuttle Radar Topography Mission digital elevation model (DEM) showed that both old and new agricultural areas are located within same closed drainage basin. The fluvial channels of these catchments, which were developed during wet climatic pluvial, have largely been obliterated by the prevailing aridity and often buried under aeolian deposits. However, the new cultivations have been developed on the fingertips of these fluvial channels, while the old fields occupy the low‐level playas. The soil of the new cultivated areas is mainly lithic with a high calcium carbonate content, thus limiting the downward percolation of excess irrigation water and therefore developing perched water table and seepage through the palaeo‐channels. The automatically extracted drainage networks from DEM resemble fluvial patterns and coincide with the seepage channels slowly heading toward old cultivation. The inactive alluvial channels and landforms have to be considered when planning for new cultivation in dryland catchments to better control waterlogging and salinization hazard. It is highly recommended that newly developed seepage channels have to be detected and intercepted before reaching old agriculture areas. Therefore, the ‘dry‐drainage’ concept can be implemented as the seepage water can be conveyed into nearby playas reserved for evaporation. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
68.
利用美国环境预测中心(NCEP)资料,对2005年9月1日至10月10日汉江上游秋涝期500 hPa环流条件和700 hPa水汽场的时空分布特征进行了分析。结果表明:在汉江上游秋涝盛期,500 hPa高度距平场呈现出" ,-, "波列结构。700 hPa主要水汽源在孟加拉湾和南海地区。同时段水汽通量散度场EOF分析表明,汉江上游水汽通量散度同南海和孟加拉湾北部具有相同的变化符号;小波分析进一步揭示出汉江上游和南海地区水汽通量散度都存在准2周和准1周的振荡。强降水一般出现在几种不同频率振荡的负值位相叠加的时段。 相似文献
69.
提出了一个应用水文上降水产生流量过程线的变化原理,仅用降水资料来推算流域洪涝指数,用量化指标来预报未来流域洪涝强度的研究思路和方法。利用流域内测站雨量计算出流域的有效综合面雨量(考虑了前一段时间内的逐日流域面雨量的不同贡献)。复核流量(或水位)等洪涝有关资料与流域有效综合面雨量的关系,最终确定出各级洪涝指数的流域有效综合面雨量的大小。在实际预报业务中,利用流域的实况面雨量和预报面雨量计算出未来流域某日的有效综合面雨量,对其值与已确定的各级洪涝指数的有效综合面雨量大小进行比较分析,最终判断未来流域可能出现的洪涝等级和强度。 相似文献
70.
城市暴雨内涝情景模拟与灾害风险评估 总被引:5,自引:1,他引:4
Scenario modelling and the risk assessment of natural disasters is one of the hot-spots in disaster research.However,up until now,urban natural disaster risk assessments lack common procedures and programmes.This paper selects rainstorm waterlogging as a disaster to research,which is one of the most frequently occurring hazards for most cities in China.As an example,we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing’an District of Shanghai.Based on the basic concept of disaster risk,this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods.Through this analysis of vulnerability and exposure,we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments.A grid-based Geographical Information System (GIS) approach,including an urban terrain model,an urban rainfall model and an urban drainage model,was applied to simulate inundation area and depth.Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys,which were further applied to analyse vulnerability,exposure and loss assessment.Finally,the ex-ceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities.A framework was also devel-oped for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss.This is a new explora-tion for small-scale urban natural disaster scenario simulation and risk assessment. 相似文献