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991.
内蒙古东部近54年气候变化对生态环境演变的影响   总被引:14,自引:2,他引:14  
利用4个代表站1951—2004年温度和降水资料,通过气候统计诊断分析方法,从气候要素变化趋势、基本气候状态特征以及生态环境演化趋势等方面,研究气候变化对生态环境演变的影响。结果表明:(1)近54年来东部区温度呈显著的升高态势。降水量波动性较大,总体上呈缓慢的增加趋势,但趋势不明显,属于气候自然波动的范围,而1998年至本世纪降水量呈下降趋势,并存在11年和22年的周期性变化。(2)无论是温度还是降水,目前都处于高的气候基本态和高气候变率时期,致使极端气候事件呈增加趋势。气候的变干、变暖以及变率的增大,加剧了内蒙古东部地区干旱化的程度。由此引起一系列生态环境问题,如湿地萎缩、草场退化等。(3)从示范区卫星遥感资料获悉,固定沙地面积的增加,说明科尔沁沙地沙漠化整体出现生态良性好转,但各类沙地图斑数的增加,表明在目前的气候条件下,沙地破碎化程度加剧,沙漠化局部有所恶化。  相似文献   
992.
The dynamics of water and energy fluxes in the high mountains of central Norway was studied along micro-spatial topographic gradients in different altitudes and regions of the Scandes. Landscape ecological processes like snow accumulation during winter, snow melting, evaporation, percolation, soil moisture variability and temperature variations were quantified. Combining spatio-temporal data on physical environment functioning and vegeta-tion patterns resulted in a process-oriented characterisation of high mountain ecosystems. Extensive data from long-term measurements were synthesised illustrating the influence of micro-climate, snow cover, and soil moisture on high mountain ecosystem functioning. The results reveal that the micro-climatic impact on the vegetation is predominantly determined by snow cover overlaying soil moisture gradients. Water only becomes superior where near-surface water saturation and flooding occur. A lack of soil moisture availability was not found during any time of the year even under driest site conditions. Contrasting literature, the Norwegian mountain vegetation was found to be interpreted by environmental variable con-stellations excluding drought stress.  相似文献   
993.
Trends of annual and monthly temperature, precipitation, potential evapotranspi-ration and aridity index were analyzed to understand climate change during the period 1971–2000 over the Tibetan Plateau which is one of the most special regions sensitive to global climate change. FAO56–Penmen–Monteith model was modified to calculate potential evapotranspiration which integrated many climatic elements including maximum and mini-mum temperatures, solar radiation, relative humidity and wind speed. Results indicate gen-erally warming trends of the annual averaged and monthly temperatures, increasing trends of precipitation except in April and September, decreasing trends of annual and monthly poten-tial evapotranspiration, and increasing aridity index except in September. It is not the isolated climatic elements that are important to moisture conditions, but their integrated and simulta-neous effect. Moreover, potential evapotranspiration often changes the effect of precipitation on moisture conditions. The climate trends suggest an important warm and humid tendency averaged over the southern plateau in annual period and in August. Moisture conditions would probably get drier at large area in the headwater region of the three rivers in annual average and months from April to November, and the northeast of the plateau from July to September. Complicated climatic trends over the Tibetan Plateau reveal that climatic factors have nonlinear relationships, and resulte in much uncertainty together with the scarcity of observation data. The results would enhance our understanding of the potential impact of climate change on environment in the Tibetan Plateau. Further research of the sensitivity and attribution of climate change to moisture conditions on the plateau is necessary.  相似文献   
994.
Based on temperature reconstruction and proxy data from 14 sites in the Northern Hemisphere, this paper focused on comparing the cycles of temperature variations between the Arctic and other areas, including Atlantic, Europe, China, Asia, Pacific, Indian Ocean, and America during the transition from the last Interstade to the Last Glacial Maximum, from the Last Glacial Maximum to megathermal period in Holocene and the transition of the Little Ice Age (LIA) by the methods of Singular Spectrum Analysis (SSA) and Maximum Entropy Spec-trum (MES). The results showed that environmental changes in the Arctic are most similar to that in the North American and better similar to Asia, Atlantic and Pacific, the least similar to Indian Ocean and Europe. The 1500-year oscillation of temperature existed both in Arctic and Europe.  相似文献   
995.
综合迄今中国境内湖泊沉积、冰心、泥炭、石笋、古土壤和洪积物获得的全新世数据及序列表明,早全新世气候变化是不稳定的,至少存在一次明显的降温事件,且表现为区域差异,其根本原因是受不同气候系统、复杂地形(特别是高原)的制约。但是,将不同地区、存在于9.0~7.6ka BP期间、500a至200a不等的气候突变或波动和记录与环北大西洋的8.2ka BP气候突变事件相对应,并归因于Laurentide冰盖的崩塌冰融水注入北大西洋造成的降温显然是草率的。中国主要地处季风气候区,加上目前我们所得序列的不同年代、样品精度、不同材料以及缺乏对气候事件前后精确的年代数据的控制,对于中国是否存在相同的或相似的气候降温事件是值得商榷的。如果真的存在,其时间跨度、降温幅度以及诱发机制又是什么,均需进一步认真研究。  相似文献   
996.
BOOK REVIEWS     
Book Reviewed in this article: Rabat: Urban Apartheid in Morocco . Janet Abu -Lughod . Marketplaces in a Developing Country: The Case of Western Nigeria . Isaac Ayinde Adalemo . Farming Development and Space: A World Agricultural Geography . Bernd Andreae . Section and Party: A Political Geography of American Presidential Elections, from Andrew Jackson to Ronald Reagan . J. Clark Archer and Peter J. Taylor . Women and Space: Ground Rules and Social Maps . Shirley Ardener , ed. European Progress in Spatial Analysis . R. J. Bennett , ed. The Origins of Academic Geography in the United States . Brian W. Blouet Geographic Perspectives on Global Problems . Ronald Reed Boyce . Seasonal Dimensions to Rural Poverty . Robert Chambers , Richard Longhurst and Arnold Pacey eds. The New Nationalism and the Use of Common Spaces: Issues in Marine Pollution and the Exploitation of Antarctica . Jonathan I. Charney , ed. Communications Tomorrow: The Coming of the Information Society . Edward Cornish , ed. The Design of Suburbia . Arthur Edwards . Explorer on the Northern Plains: Lieutenant Gouverneur K. Warren's Preliminary Report of Explorations in Nebraska and Dakota in the Years 1855–56–57. With an Introduction by Frank N. Schubert . The Changing Climate: Responses of the Natural Flora and Fauna . Michael J. Ford . Essentials of Physical Geography . Robert E. Gabler , Robert J. Sager , Sheila Brazier , and Daniel L. Wise. The Road to Jaramillo . William Glen . Valued Environments . John R. Gold and Jacquelin Burgess , eds. Proximity and Preference: Problems in the Multidimensional Analysis of Large Data Sets . Reginald G. Golledge and John N. Rayner , eds. A Search for Common Ground . Peter Gould and Gunnar Olsson , eds. Geography: Its History and Concepts . Arild Holt -Jensen . A Population Geography . Huw R. Jones . The Human Mosaic: A Thematic Introduction to Cultural Geography, 3rd ed. Terry G. Jordan and Lester Rowntree . Urban Social Geography: An Introduction . Paul Knox . The Anatomy of Job Loss: The How, Why and Where of Employment Decline . Doreen Massey and Richard Meegan . The Information Society as Post-Industial Society . Yoneji Masuda . Map Librarianship, 2nd ed. Harold Nichols . India: Cultural Patterns and Processes . Allen G. Noble and Ashok K. Dutt , eds. The God that Limps: Science and Technology in the Eighties . Colin Norman . Geography: An Introductory Perspective . Robert E. Norris , Keith D. Harries and John D. Vitek . The Politics of Technology Assessment . David M. O'Brien and Donald A. Marchand . Ethnic Segregation in Cities . Ceri Peach , Vaughan Robinson and Susan Smith , eds. Churches and Church Membership in the United States, 1980 . Bernard Quinn , Herman Anderson , Martin Bradley , Paul Goetting and Peggy Shriver . Energy in Australia: Politics and Economics . Hugh Saddler . Development from Above or Below? The Dialectics of Regional Planning in Developing Countries . Walter B. Stóuhr and D. R. Fraser Taylor , eds. Human Impact on the Ecosystem . Joy Tivy and Greg O'Hare . Plants and People: Vegetation Change in North America . Thomas R. Vale . The Mapmakers: The Story of the Great Pioneers in Cartography from Antiquity to the Space Age . John Noble Wilford .  相似文献   
997.
在对低温型食用菌生活条件和三明市低温型食用菌气候资源分析的基础上,确定了三明市低温型食用菌的气候指标,并建立气候模式。根据气候模式、地理信息系统、经济效益及交通状况等,综合评价了三明市低温型食用菌的资源状况,并以此为依据,利用G IS软件将三明市分为4个栽培区,即经济效益较低区、适宜栽培区、最适宜发展区和反季节栽培区。  相似文献   
998.
新疆物候(候鸟)与气候因子关系分析   总被引:1,自引:0,他引:1  
通过对新疆10个站4种候鸟物候及相应气候因子变化的关系分析,得出候鸟停留时间与同期日照时数及≥0℃的积温关系密切,并经过数理统计,得出用气候因子预测候鸟停留时间的数学模式,对预知一定生态环境中鸟类的迁徙具有一定指导意义。  相似文献   
999.
统计分析了郑州市7站自建站始至2005年的全部暴雨天气过程,结果显示:暴雨天气发生在夏半年(4~10月);单站暴雨年平均1.3~2.8次,区域性暴雨年平均1.5次;郑州地区暴雨出现次数南部多于北部,东部多于西部,其中登封是郑州市出现暴雨次数最多的测站;暴雨次数的年际变化呈明显波动形势;造成郑州市夏季暴雨的主要天气系统有低槽型、切变线型、副高西伸型、台风或台风倒槽型等。  相似文献   
1000.
采用灰色关联度分析了安阳夏玉米生育期间主要气象要素与夏玉米产量的关系,明确了当地夏玉米产量在年度间的差异主要以积温为主导因素,不同生育期中的气候因素以拔节-乳熟期的光照和降水量对产量影响最大,而乳熟-成熟的降水量对产量的影响程度最弱。  相似文献   
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