新疆北部地区积雪深度变化特征及未来50a的预估

分析比较参加CMIP3计划的全球气候模式,在20C3M下各模式1961-1999年平均积雪深度和观测资料比较的基础上,检验了模式对积雪深度的模拟能力.在此基础上,选用INM-CM3.0和CGCM-T47_1模式对北疆地区未来50 a的积雪变化进行了预估.由于受GCM的空间分辨率和新疆北部地区地形、盆地沙漠下垫面、水汽来源和干旱气候环境的影响,CMIP3模式的GCM在新疆北部地区的模拟能力有限.通过相关系数和均方差误差的双重检验,选取了在新疆地区模拟能力较好的INM-CM3.0和CGCM-T47_1模式的模拟结果对新疆地区未来的积雪变化进行了预测.结果表明,在A1B、B1情景下,2002-2050年,总体上新疆北部地区的积雪深度均呈减少趋势;A2情景下,INM-CM3.0、CGCM-T47-1模式在准葛尔盆地地区积雪变化的模拟结果存在差异,但未来40 a新疆地区除天山附近外,积雪深度变化呈减少趋势.     

Reviews

Bppks reviewed:
Reginald Appleyard, (ed.) Emigration dynamics in developing countries. Vol. IV: the Arab region
Curt Meine and Richard L. Knight, (eds.) The Essential Aldo Leopold. Quotations and Commentaries
Jyoti Shankar Singh, Creating a New Consensus on Population
Walden Bello, Shea Cunningham and Li Kheng Poh, A Siamese Tragedy
Bart Makaske, Anastomosing Rivers: Forms, Processes and Sediments
Philip Micklin, Managing Water in Central Asia
Iwao Kobori and Michael H. Glantz, (eds.) Central Eurasian Water Crisis: Caspian, Aral, and Dead Seas
John R. Gold and George Revill, (eds.) Landscapes of Defence
Monica Trujillo Amado Ordonez and Carlos Hernandez, Risk Mapping and Local Capabilities: Lessons from Mexico and Central America
R. Dalton, H. Fox and P. Jones, Classic Landforms of the White Peak (second edition), Classic Landforms of the Dark Peak (second edition)
Tatyana Saiko, Environmental Crises: Geographical Case Studies in Post-Socialist Eurasia
F. Brouwer and P. Lowe, (eds.) CAP Regimes and the European Countryside
Andrew Goudie, The Human Impact on the Natural Environment (fifth edition)
Jean Radvanyi, La Nouvelle Russie (second edition)
John Vogler, The Global Commons: Environmental and Technological Governance (second edition)     

农村社会经济因素变化对嘉陵江产沙量的影响

以大量实测资料为基础,通过自然科学与人文科学的跨学科研究,分析了农村社会经济因素变化对嘉陵江产沙量的影响。发现嘉陵江年产沙量与径流量之间的双累积曲线上出现两个下偏转折,分别发生于1983~1984年和1992~1993年。第一转折点的出现与流域社会经济因素的变化有密切的关系;第二个转折点与长江上游水土保持重点治理工程有密切关系,但社会经济因素的影响也不容忽视,因为第二转折点与诸多社会经济因素变化的转折点具有同步性。从嘉陵江北碚站年产沙量与农民人均纯收入、农民人均购买燃料支出和农业产值占GDP百分比的相关关系中查明了3个临界点,即当农民人均收入<400元/a时,由于贫穷所产生的对土地的压力,使得侵蚀产沙量突变式增大;当农民人均燃料支出<20元/a时,农民将主要通过砍伐树木和灌木、收集林下的枯枝落叶、割草甚至于挖掘草根来获取燃料,使得侵蚀产沙量突变式增大;当农业产值占GDP百分比>40%时,农村人口对土地的压力使得侵蚀产沙量突变式增大。建立了北碚站年产沙量和已转移的乡村劳动力数量占乡村劳动力总数百分比、农村人均纯收入和农村人均用于购买燃料的支出之间的多元回归方程,并估算出,上述3个变量的变化对北碚站年产沙量变化的贡献率分别为36.00%,21.59%和42.41%。     

Potential Impacts of Climate Change on Fire Regimes in the Tropics Based on Magicc and a GISS GCM-Derived Lightning Model

Investigations of the ecological, atmospheric chemical, and climatic impacts of contemporary fires in tropical vegetation have received increasing attention during the last 10 years. Little is known, however, about the impacts of climate changes on tropical vegetation and wildland fires. This paper summarizes the main known interactions of fire, vegetation, and atmosphere. Examples of predictive models on the impacts of climate change on the boreal and temperate zones are given in order to highlight the possible impacts on the tropical forest and savanna biomes and to demonstrate parameters that need to be involved in this process. Response of tropical vegetation to fire is characterized by degradation towards xerophytic and pyrophytic plant communities dominated by grasses and fire-tolerant tree and bush invaders. The potential impacts of climate change on tropical fire regimes are investigated using a GISS GCM-based lightning and fire model and the Model for the Assessment of Greenhouse Gas-Induced Climate Change (MAGICC).     

未来气候变化对中国荒漠化的潜在影响

气候变化与荒漠化间的反馈机制已成为全球研究的重点问题之一 ,减缓温室气体增加与防治荒漠化也成为全球协同行动的领域。作为一个发展中国家 ,中国的荒漠化及其防治不仅影响到全球气候变化 ,同时气候变化对中国的荒漠化也会产生显著影响。文中采用全国 1914个气象站的数据作为基线数据 ,在根据植被区划图在青藏高原上对Thornthwaite方程做适当订正的基础上 ,选择未来两个具代表性的年份 (2 0 30年和 2 0 5 6年 )用HadCM 2模型来预测全球变化框架下中国未来荒漠化生物气候类型区的变化。结果表明 ,各生物气候类型区的面积基本上均呈增加的趋势 ,其中以亚湿润干旱区增加为主 ,半干旱区次之。与 1990年的 395 6 5 81万km2 的荒漠化生物气候类型区面积相比 ,在GHGs年增量为 1%且考虑硫酸盐溶胶影响的情况下 ,2 0 30年和 2 0 5 6年分别提高了 11 33%和12 94% ,而在GHGs年增量为 0 5 %且考虑硫酸盐溶胶影响的情况下 ,则分别提高了 3 75 %和6 95 % ,比前者分别减少了 7 5 8和 5 99个百分点。虽然在GHGs年增量 0 5 %的减少情况下 ,中国未来荒漠化生物气候类型区面积扩大和程度加剧的速度有所减缓 ,但其总体增加仍很显著。因此进一步开展气候变化与荒漠化间相互作用的研究 ,并用以指导中国的荒漠化防治工?     

Estimating the confidence of earthquake damage scenarios: examples from a logic tree approach

Earthquake loss estimation is now becoming an important tool in mitigation planning, where the loss modeling usually is based on a parameterized mathematical representation of the damage problem. In parallel with the development and improvement of such models, the question of sensitivity to parameters that carry uncertainties becomes increasingly important. We have to this end applied the capacity spectrum method (CSM) as described in FEMA HAZUS-MH. Multi-hazard Loss Estimation Methodology, Earthquake Model, Advanced Engineering Building Module. Federal Emergency Management Agency, United States (2003), and investigated the effects of selected parameters. The results demonstrate that loss scenarios may easily vary by as much as a factor of two because of simple parameter variations. Of particular importance for the uncertainty is the construction quality of the structure. These results represent a warning against simple acceptance of unbounded damage scenarios and strongly support the development of computational methods in which parameter uncertainties are propagated through the computations to facilitate confidence bounds for the damage scenarios.     

Rigid‐plastic seismic design of reinforced concrete structures

In this paper a new seismic design procedure for Reinforced Concrete (R/C) structures is proposed—the Rigid‐Plastic Seismic Design (RPSD) method. This is a design procedure based on Non‐Linear Time‐ History Analysis (NLTHA) for systems expected to perform in the non‐linear range during a lifetime earthquake event. The theoretical background is the Theory of Plasticity (Rigid‐Plastic Structures). Firstly, a collapse mechanism is chosen and the corresponding stress field is made safe outside the regions where plastic behaviour takes place. It is shown that this allows the determination of the required structural strength with respect to a pre‐defined performance parameter using a rigid‐plastic response spectrum, which is characteristic of the ground motion alone. The maximum strength demand at any point is solely dependent on the intensity of the ground motion, which facilitates the task of distributing required strength throughout the structure. Any artificial considerations intended to adjust results according to empirical observations are avoided, which, from a conceptual point of view, is considered to be an advantage over other simplified design procedures for seismic design. The procedure is formulated using a step‐by‐step format followed by a design example of a 4‐storey‐R/C‐plane‐frame. Results are compared with refined NLTHA and found to be extremely encouraging. Copyright © 2006 John Wiley & Sons, Ltd.     

气候变化国家评估报告(Ⅱ):气候变化的影响与适应

Significant and various impacts of climate change have been observed in China, showing both positive and adverse effects, dominantly the latter, in different sectors and regions. It is very likely that future climate change would cause significant adverse impacts on the ecosystems, agriculture, water resources, and coastal zones in China. Adoption of adaptive measures to climate change can alleviate the adverse impact, therefore such measures should be incorporated into the medium-and long-term national economic and social development plans. Because China has done relatively limited research on impact assessment and our understanding of climate change is incomplete, the current impact assessment methodologies used and results obtained contain many uncertainties. To reduce the uncertainties and develop effective and practical climate change adaptive measures in China, it is necessary to emphasize regional case studies on adaptive measures, enlarge the scope of climate change research, and strengthen the assessment of the impacts resulted from extreme weather/climate events.     

GCM STUDIES ON ANTHROPOGENIC CLIMATE CHANGE IN CHINA*

Impacts of human activities on climate change as simulated by the general circulation models (GCMs)in China for the recent ten years have been summarized and reviewed in this paper.The researches show that it might be getting warmer over China due to the greenhouse effects.The atmospheric circulation and precipitation also might be changed due to the greenhouse effects.The assessments and evaluations of the models over the globe and China have also been presented in this paper.     

Recovery from demographic shock in the New Länder of Germany

After the fall of the Berlin Wall in November 1989, East Germany experienced a demographic shock as the ensuing insecurity and disorientation of the population was mirrored in their demographic behaviour. The situation is examined with respect to marriage, fertility and mortality. There are now signs of recovery but most people in the New Länder are still traumatised by events: nuptiality and fertility are still extremely low, while mortality is rapidly moving towards West German levels. Future demographic development will very much depend on socio-economic development and the provision of both hard and soft infrastructure conducive to stable partnerships and families since the current 'framework' has proved to be particularly unfriendly to women and children.