我国20世纪地理学发展回顾及新世纪前景展望：祝贺中国地理学会创立9 …   总被引：34，自引：1，他引：33  

吴传钧  张家桢 《地理学报》1999,54(5):385-390

中国地理学会创立９０年来,我国地理学经历了由近代地理学向现代地理学发展的历程,中国地理学会在团结了广大地理工作者为促进学科发展和为国民经济建设服务等方面的重要的作用,展望新世纪,在知识经济时代,我国地理学应加强在基础理论,地理环境的变化和保护,地区资源系统,区域综合发展,地理信息与技术等方面的研究。  相似文献   

21世纪的地球信息科学及其应用   总被引：6，自引：2，他引：6  

廖克 《测绘科学》2001,26(2):1-6

分析了地图学、遥感、地理信息系统及全球定位系统的发展 ,为地球信息科学的建立奠定了基础。论述了地球信息科学的内涵、理论基础、技术体系以及地球信息图谱等基本概念 ,阐述了地球信息科学在资源清查与管理、经济与社会可持续发展规划决策与管理、城市规划与现代化管理、农业规划决策与生产管理、灾害预测与灾情评估、环境污染与生态变化监测、全球变化监测与研究等方面的应用前景。  相似文献   

Assimilation of the FY-4A AGRI Clear-Sky Radiance Data in a Regional Numerical Model and Its Impact on the Forecast of the “21·7” Henan Extremely Persistent Heavy Rainfall     

Lan XU  Wei CHENG  Zhongren DENG  Juanjuan LIU  Bin WANG  Bin LU  Shudong WANG  Li DONG 《大气科学进展》2023,40(5):920-936

Assimilation of the Advanced Geostationary Radiance Imager(AGRI) clear-sky radiance in a regional model is performed. The forecasting effectiveness of the assimilation of two water vapor(WV) channels with conventional observations for the “21·7” Henan extremely heavy rainfall is analyzed and compared with a baseline test that assimilates only conventional observations in this study. The results show that the 24-h cumulative precipitation forecast by the assimilation experiment with the addition ...  相似文献   

汉江中下游突发性水污染事故污染物运移扩散模型   总被引：12，自引：3，他引：9       下载免费PDF全文

王庆改  赵晓宏  吴文军  杨木水  马强  刘坤 《水科学进展》2008,19(4):500-504

以汉江中下游为例,基于MIKE 11模型的降雨径流模块、水动力模块、对流扩散模块建立了汉江中下游的降雨-径流模型、水动力模型和对流-扩散模型,通过对模型进行率定和验证,表明该模型具有较理想的模拟效果;在此基础上运用构建的模型模拟了汉江中下游2003年冬季、夏季不同水文情况下,突发性水污染事故中污染物的运移扩散过程,定量模拟了突发性水污染事故发生后,汉江不同地点处污染物到达的时间和浓度值,并对突发风险事故的影响范围、程度、时间做出定量预报.  相似文献   

社交媒体在“21世纪海上丝绸之路”沿线国家海洋防灾减灾中的应用及借鉴     

解晓茹  武文  郭佩芳 《南京气象学院学报》2018,10(3):386-394

以Twitter、Facebook为代表的社交媒体在防灾减灾方面的作用越来越受到关注.中国是世界上海洋灾害最为严重的国家之一,海洋防灾减灾是目前我国面临的十分紧迫的问题.近年来,智能手机和网络的普及让中国的社交媒体进入了人们的日常生活.借鉴国外社交媒体在防灾减灾方面的经验,我们认为中国的社交媒体在海洋防灾减灾中同样拥有巨大潜力.本文首先介绍了"21世纪海上丝绸之路"沿线的几个国家利用社交媒体开展海洋防灾减灾工作的情况,随后总结了当前中国在海洋灾害预警、灾害信息传播及灾害管理等方面的实际情况.最后,借鉴国外先进的经验和做法,为进一步提升中国社交媒体在海洋防灾减灾工作中的作用提出了启示性的对策建议.  相似文献   

Old open clusters: the interesting case of Berkeley 21     

M. Tosi  L. Pulone  G. Marconi  & A. Bragaglia 《Monthly notices of the Royal Astronomical Society》1998,299(3):834-844

We present CCD BVI photometry of the old open cluster Berkeley 21, one of the most distant clusters in the Galactic anticentre direction, and possibly the lowest metallicity object in the open clusters sample. Its position and metal abundance make it very important for the study of the Galactic disc. Using the synthetic colour–magnitude diagram method, we estimate values for the distance modulus ( m  − M )₀ = 13.4–13.6, reddening E ( B  −  V ) = 0.74–0.78 (with possible differential absorption), and age = 2.2–2.5 Gyr.  相似文献   

滇21井水位微动态特征研究   总被引：1，自引：1，他引：0  

施子岩 《地震研究》1998,21(3):286-291

本文通过对滇２１井的地质构造部位、水文地质条件、井孔结构等方面的论述,应用该井水位观测结果,以地下水微动态理论为指导,分析了气压、固体潮、降雨等干扰因素对水位的影响,归纳出该井水位正常动态特征,探讨了识别震兆异常的方法,为综合分析多井水位异常打下了基础。  相似文献   

Metal distributions and their fluxes at the coastal boundary of a semi-enclosed ria     

Antonio Cobelo-García  Ricardo Prego  Maite DeCastro 《Marine Chemistry》2005,97(3-4):277-292

Water column samples have been collected in the outer channel of the Ferrol Ria (NW Spain) during four occasions over a tidal cycle. The objective was to study the exchange of dissolved and particulate Cd, Cu, Pb and Zn and particulate Al, Fe and Si between the ria and the adjacent coastal waters. This study provides the first extensive dataset on dissolved and particulate metal concentrations in the water column of a Galician ria. Typical concentrations of dissolved Cd (96 ± 31 pM), Cu (8 ± 4 nM), Pb (270 ± 170 pM) and Zn (21 ± 10 nM) were similar than in other European Atlantic shelf and coastal waters. The fraction of metals in the particulate phase followed the trend: Pb > Cu Zn > Cd. The outgoing water from the ria was enriched in dissolved and particulate Cu, Pb and Zn compared with incoming waters, whereas Cd concentrations were similar for both waters. The suspended particulate matter was composed of a mixture of marine and continental material. The latter end-member was found to arise from the metal-rich ria bed sediments, which is diluted by the dominant metal-poor marine end-member. The net output flux of Cu from the channel is balanced by the freshwater inputs to the ria, and the net Zn flux gave a positive output to coastal waters. For Pb, the net flux to the coastal waters is less than that input from the rivers, as a result of its particle reactivity and deposition in sediments. On the contrary, a net input flux of dissolved Cd from coastal waters was observed, highlighting the oceanic source of this metal in the Galician rias. Results from the budget calculations are in agreement with the differential geochemical behavior of these elements in coastal waters.  相似文献   

Spatial patterns and driving forces of land use change in China during the early 21st century     

LIU Jiyuan  ZHANG Zengxiang  XU Xinliang  KUANG Wenhui  ZHOU Wancun  ZHANG Shuwen  LI Rendong  YAN Changzhen  YU Dongsheng  WU Shixin  JIANG Nan 《地理学报》2010,20(4):483-494

Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the “Grain for Green” policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of “Western Development”, “Revitalization of Northeast”, coupled with rapidly economic development during this period.  相似文献   

21世纪初中国土地利用变化的空间格局与驱动力   总被引：33，自引：15，他引：18  

刘纪远  张增祥  徐新良  匡文慧  周万村  张树文  李仁东  颜长珍  于东升  吴世新  江南 《地理学报(英文版)》2010,20(4):483-494

Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the "Grain for Green" policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of "Western Development", "Revitalization of Northeast", coupled with rapidly economic development during this period.  相似文献