Paleolimnological records of recent glacier recession in the Rwenzori Mountains,Uganda-D. R. Congo

The status of tropical glaciers is enormously important to our understanding of past, present, and future climate change, yet lack of continuous quantitative records of alpine glacier extent on the highest mountains of tropical East Africa prior to the 20th century has left the timing and drivers of recent glacier recession in the region equivocal. Here we investigate recent changes (the last 150–700 years) in lacustrine sedimentation, glacier extent, and biogeochemical processes in the Rwenzori Mountains (Uganda- Democratic Republic of Congo) by comparing sedimentological (organic and siliciclastic component determined by loss-on-ignition; LOI) and organic geochemical profiles (carbon and nitrogen abundance, ratio, and isotopic composition of sedimentary organic matter) from lakes occupying presently glaciated catchments against similar profiles from lakes located in catchments lacking glaciers. The siliciclastic content of sediments in the ‘glacial lakes’ significantly decreases towards the present, whereas ‘non-glacial lakes’ generally show weak trends in their siliciclastic content over time, demonstrating that changes in the siliciclastic content of glacial lake sediments primarily record fluctuations in glacier extent. Radiometric dating of our sediment cores indicates that prior to their late 19th-century recession Rwenzori glaciers stood at expanded ‘Little Ice Age’ positions for several centuries under a regionally dry climate regime, and that recession was underway by 1870 AD, during a regionally wet episode. These findings suggest that the influence of late 19th century reductions in precipitation in triggering Rwenzori glacier recession is weaker than previously thought. Our organic geochemical data indicate that glacier retreat has significantly affected carbon cycling in Afroalpine lakes, but trends in aquatic ecosystem functioning are variable among lakes and require more detailed analysis.     

Charting the emergence of ‘global water initiatives’ in world water governance

Over the last century, the aperture of water governance has widened beyond local and regional schemes to include a growing number of dynamic organizations and events with a “global” scope. Until recently, little had been written about the historical development of global water governance, institutional connectivity within the field, or key organizational successes and failures as perceived by water experts. This paper provides water scientists, managers, policymakers, and those with an interest in international water issues with an overview of global initiatives. It charts the emergence of a set of institutions and events, referred to as “global water initiatives,” or GWIs, using a survey of water experts and other research. Institutional diversity among GWIs is described by defining four distinct types of initiatives and specific differences in scope and programmatic orientation. This overview also entails the historical paradigms of water management, evaluation of the results of the growth and proliferation of numerous new GWIs in recent decades, and some recommendations for supporting and sustaining GWI efforts in order to foster and improve multilevel water management in the future.     

长白山地区火山机构信息系统的建立

长白山火山机构信息系统是在系统设计与分析基础上建立的,共有5个模块组成:①长白山地区火山岩岩石化学数据库系统;②常量元素岩石化学分析系统;③微量元素岩石化学分析系统;④长白山火山构造信息系统;⑤长白山地区岩性岩相信息系统。数据库系统模块用VB语言开发完成;分析系统模块(2个)的建立是通过界面设计、结构分析、编程实现的;火山机构信息系统及岩性、岩相信息系统模块是在Mapinfo软件的支持下完成的。     

现代地壳运动与地震监测预报研究的现状和发展趋势

综述了近年来美国、日本的GPS连续观测系统和INSAR空间测地技术在现代地壳运动和地震监测预报研究中的应用现状和发展趋势。     

空间GPS无线电掩星反演大气参数方法及其应用

给出了空间无线电掩星反演大气参数的原理及其误差估计方法,介绍了国内外在该领域的研究进展。并针对该技术的一些特点,指出了若干尚需解决的问题。     

基于PCWin98经济网络分布式动力大地测量学数据库的设计与实现

分析了动力大地测量学数据的结构和应用特点,结构现有网络和计算机软硬件状况,兼顾使用者的计算机水平和建库的人物力条件,得出了建立地测量学科数据库的思路和方案,建成基于Ｗｉｎ９８经济网络分布式动力大地测量学数据库。基于Ｗｉｎ９８经济网络、以资源共享方式集成的数据库系统开发环境有很大的在线数据存储能力、灵活分散式的数据库实现模式和调用功能。实现了以往大型计算机才能完成的系统。目前,系统平时能满足一般需要,必要时完成大型复杂任务。已拥有中国及其邻区原始气象数据、全球平均气压数据、超导观测数据、中国邻区重力场数据、地球自转及其有关数据、海潮模型、重力模型、软件等子库,容量达数十千兆,为科研提供快捷的数据服务。为目前普遍使用的区域网用户提供一种可行的科学数据库实现模式。     

资源环境信息系统集成平台的设计、实施与应用

“数字地球”概念的提出对地理信息系统的集成开发提出了新的要求。针对目前一些主流的地理信息系统数据库设计及系统集成技术,比较分析了不同解决方案的特点及存在的问题,并通过具体实例,展示不同方案的实际应用效果。为实用型的地理信息系统应用软件的设计和实施提供参考。     

土壤环境变化与可持续发展

土壤环境的变化在短时间内是缓慢且不易察觉的,但是在地球历史的演化中,它留下了一丝丝印迹,这就是古土壤,它包含了当时环境的大量依据,是５大成土因素的综合产物,当人类出现后,尤其是近百年来在复杂的自然因素上又叠加了人为作用,并且这种作用的强度与日俱增,当它对土壤的影响超过其它作用后,例形成人为土壤,同时,也可能引起土壤退化和土壤污染,这些变化同全球变化和社会持续发展密切相关。     

德国迁都柏林过程中的地球信息技术─-祝贺陈述彭院士2000年2月14日八十华诞生日快乐

联邦德国议会1991年决定, 议会与政府核心部门在2000年前从波恩迁回柏林 ,波恩保留联邦行政管理中心的功能。为了按时准确地规划和完成落实迁都建设工程,在柏林建设国家行政办公设施和国家工作人员生活居住设施,解决波恩地区因国家机关迁离而遭受的损失,参加建设的许多部门应用了地球信息技术。文中介绍了“柏林房地产信息系统”,“联邦议会与政府核心区建设信息系统”,“物业管理信息系统”,“波恩地区经济地理信息系统”以及地球信息技术在交通和环境管理中的应用。     

遥感技术与其全球变化的研究

全球变化是当今地球科学研究的热点。具有全球观测能力的遥感技术成为全球变化研究的重要技术手段。本文对全球变化研究的主要内容进行了简要回顾 ,对遥感技术在全球变化研究当中的地位和作用进行了论述 ,并对一些新一代的传感器作了简要介绍 ,同时对我国遥感工作者在全球变化方面的一些工作作了介绍。