新疆洪旱灾害与大尺度气候强迫因子的联系

通过对新疆洪灾灾害历史资料和太阳黑子、ENSO事件年数据以及北大西洋涛动指数的分析,表明在太阳黑子极低值年或不活跃年,新疆易发生重大洪灾,而在太阳黑子低值年或相对不活跃年,新疆也易发生重大旱灾。近200a来,新疆重大洪旱灾害绝大部分都发生在太阳黑子的低谷时期。ENSO事件对新疆夏季降水的影响效应明显。因而该事件对新疆的洪旱灾害也产生了影响。对近50年来灾害统计资料分析显示,与拉尼娜年相比,在厄尔尼诺年新疆更易发生洪旱灾害。20世纪后半段新疆洪旱灾害指数与北大西洋涛动指数进行对比可以发现．夏季NAO指数与新疆洪水灾害之间存在大致上的反相关系。而冬季NAO指数与新疆干旱灾害之间存在比较明显的反相关系。     

Dynamical Tropopause Variability and Potential Vorticity Streamers in the Northern Hemisphere —— A Climatological Analysis

This study presents a 44-year climatology of potential vorticity （PV） streamers in the Northern Hemisphere based upon analyses of the ERA-40 reanalysis data set. A comparison to an existing 15-year climatology yields very good agreement in the locations of PV streamer frequency maxima, but some differences are found in the amplitude of frequencies. The climatology is assessed with the focus on links between PV streamer frequencies and the synoptic- and planetary-scale variability of the dynamical tropopause.
A comprehensive overview is provided on where （zonally） and when （seasonally） short-term variability throughout the extra-tropical and sub-tropical tropopause is enhanced or reduced. Several key processes that influence this variability are discussed. Baroclinic processes, for example, determine the variability in the storm-track areas in winter, whereas the Asian summer monsoon significantly influences the variability over Asia.
The paper also describes links between the frequency of PV streamers in the extra-tropical and subtropical tropopause and three major northern hemisphere teleconnection patterns. The observed changes in the PV streamer frequencies are closely related to concomitant variations of PV and its gradient within the tropopause region. During opposite phases of the North Atlantic Oscillation the location of the streamer frequency maxima shifts significantly in the Atlantic and European region in both the extra-tropics and subtropics. The influence of ENSO on the streamer frequencies is most pronounced in the subtropical Pacific.     

北非地区海-陆热力差异与夏季江淮流域旱涝的关系

基于NCEP/NCAR月均再分析资料和中国743站降水资料,根据夏季江淮流域51 a(1954-2004年)区域旱涝指数的年代际变化特征,确定北非地区作为研究的关键区.分析发现,关键区的地表温度异常在冬季具有较好的持续性,冬季北大西洋涛动是导致这种异常持续性的重要原因之一.通过对前冬北非地区地表温度和夏季江淮流域降水的SVD分析发现:当北非大陆地区偏冷,其西北侧的海区偏暖时,江淮流域夏季的降水将整体偏多;反之,江淮流域夏季的降水整体偏少.进一步研究发现,北非地区海陆地表温度异常的对比,要比其中单一海洋或陆地区域的异常对夏季江淮流域的旱涝有更好的指示能力.文中定义了一个海陆热力差异指数来表征这种地表温度异常的对比程度,该指数和夏季江淮流域旱涝指数呈较好的正相关关系,并且对夏季江淮流域极端旱涝年份也有较好的指示,认为该指数可以作为一个指示江淮流域整体旱涝事件的预报因子.     

潮沟成因类型及其影响因素的探讨

潮沟是潮坪上最活跃的微地貌单元。从成因角度分出了滩面水流冲剧型、潮流辐聚侵蚀型、陆源水流侵蚀继承型和泻湖广海间潮流侵蚀型等四种潮沟类型。根据各地潮沟发育程度的明显差异,提出了影响潮沟发育的七个重要因素。     

长江三峡坝区汛期降水的气候背景分析及其与北太平洋海温的关系

对长江坝区汛期降水的气候背景进行了分析后指出：坝区汛期降水异常与ＥＡＡ相关链,特别是东亚这一段遥相关型有明显联系,进而探讨了它与前期北太平洋海水温度的关系。     

青藏高原东北侧7月少雨流型的研究

根据青藏高原东北侧9个代表站1951—2000年历年7月的降水量资料,确定了5个多、少雨年。再用NCEP／NCAR再分析格点资料,分别求出850,700,600,500,200,100,70,50和30hPa共计9个层次上多、少雨年份7月月平均合成位势高度场。计算了500hPa合成高度场与其余各个层次合成高度场流型的相似性度量以及各个层次的东亚北风指数。结果表明：20世纪80年代提出的1300hPa层次上高原东北侧“西正东负”少雨流型的特征在850～70hPa整层大气中仍然存在。同时．7月少雨流型与平流层低层70,50hPa前期环流特征之间也存在联系,这些结果可供西北干旱形成研究和干旱预测业务参考。     

An approach for quantifying geomorphological impacts for EIA of transportation infrastructures: a case study in northern Spain

A methodological proposal for the assessment of impacts due to linear infrastructures such as motorways, railways, etc. is presented. The approach proposed includes a series of specific issues to be addressed for each geomorphological feature analysed—both ‘static’ and ‘dynamic’—as well as a series of steps to be followed in the process.Geomorphic characteristics potentially affected were initially identified on the basis of a conceptual activities/impacts model that helps to single out geomorphic impacts related to environmental concerns for the area. The following issues were addressed for each individual impact: nature of potential effects; indicators that can be used to measure impacts; criteria of ‘geomorphologic performance’; procedure for measurement/prediction of changes; translation of geomorphologic impacts into significant terms from the viewpoint of human concerns; possible mitigation and/or compensation measures.The procedure has been applied to a case study corresponding to a new motorway in the Basque Country, northern Spain. Geomorphological impacts considered in this analysis included: (1) consumable resources; (2) sites of geomorphological interest; (3) land units with high potential for use, high productivity or value for conservation; (4) visual landscape; (5) slope instability processes. The procedure has been designed for implementation in a Geographic Information System (GIS) environment. Details are given on the application of the method to each individual impact analysed and results are presented in both numerical and map form.Impacts assessed were initially expressed by means of heterogeneous magnitudes, depending on the geomorphological feature considered. Those geomorphological impacts were then translated into significant terms and homogeneous magnitudes. Integration was carried out on the basis of impact values thus obtained. Final integrated results were also expressed in numerical and map form.The method proposed enables comparison of alternatives as well as ‘prediction’ and assessment of impacts in terms directly related to geomorphic characteristics. It also facilitates the expression of those impacts in terms that allow integration with other types of environmental impacts.     

Impacts of Holocene climatic variations on alluvial fan activity below snowpatches in subarctic Québec

In the Lake Guillaume-Delisle area of subarctic Québec, storm-generated alluvial fans have been active sporadically throughout the Holocene. In this study, we propose that the persistence of late-lying snowpatches in fan catchments during Holocene cold episodes promoted alluvial fan activity by lowering the precipitation threshold required to trigger a torrential event. This hypothesis was tested by characterizing the depositional processes responsible for alluvial fan formation below snowpatches, and by reconstructing the Holocene alluvial fan activity. Stratigraphic and sedimentary analyses conducted on seven alluvial fans revealed that they were deposited by torrential activity leading to waterlaid, transient, or hyperconcentrated deposition. The chronology of the storm-generated alluvial fans — based on 22 radiocarbon dates — indicates that torrential activity was enhanced during the cooler Late Holocene (i.e., after ca. 3500 cal. yr BP). Snowier winters and cooler summers were beneficial to nival activity, allowing the persistence of larger snowpatches throughout the summer and fall seasons. Rainfall-induced thaw of such snowpatches during rainstorm events is inferred to have contributed to alluvial fan activity by increasing water availability. Three peaks of alluvial activity occurred during the Late Holocene (2950–2750, 1900–1400, and 800–300 cal. yr BP) and are indicative of increased storminess resulting in higher fan activity. Increased fan activity during cooler episodes was concurrent with increased runoff activity in the immediate pronival area. This stresses the importance of nivation below snowpatches and pinpoints the role of nivation in enhancing geomorphological activity during period of cooler and more humid climate in subarctic environments.     

BOOK REVIEWS

Book Reviewed in this article: Marine Resources of Kuwait: Their Role in the Development of Non-oil Resources . Fatimah H. Y. al -Abdul -Razzak Recollections of a Revolution: Geography as Spatial Science . Mark Billinge , Derek Gregory and Ron Martin Entre l'Eden et l'Utopie . Luc Bureau Developments in Political Geography . M. A. Busteed The Elements of Graphing Data . William S. Cleveland Rural Resource Management . Paul J. Cloke and Chris C. Park Third World Atlas . Ben Crow and Alan Thomas Exploitation, Conservation, Preservation: A Geographic Perspective on Natural Resource Use . Susan L. Cutter , Hilary Lambert Renwick, and William H. Renwick . Wine Regions of the Southern Hemisphere . Harm Jan de Blij Regional Development: Problems and Policies in Eastern and Western Europe . George Demko The Geographer at Work . Peter R. Gould Change in the Amazon Basin . John Hemming Geography Since the Second World War . R. J. Johnston and P. Claval Urbanization in China: Town and Countryside in a Developing Economy 1949–2000 A.D. , R. J. R. Kirkby Transport and Communications for Pacific Microstates: Issues in Organisation and Management . Christopher C. Kissling Fluvial Forms and Processes . David Knighton The Urban Millennium . Josef W. Konvitz Technological Transition in Cartography . Mark Stephen Monmonier Field Guide to Soils and the Environment: Applications of Soil Surveys . Gerald W. Olson Northern Australia: The Arenas of Life and Ecosystems on Half a Continent . Don Parkes A Killing Rain: The Global Threat of Acid Rain . Thomas Pawlick From the Family Farm to Agribusiness: The Irrigation Crusade in California and the West, 1850–1931 . Donald J. Pisani Hybrid Maize Diffusion in Kenya . Franz -Michael Rundquist Warning and Response to the Mount St. Helens Eruption . Thomas F. Saarinen and James L. Sell Coastal Geomorphology in Australia . B. G. Thom Tropical Rain Forests of the Far East , 2nd ed . T. C. Whitmore The Dark Side of the Earth . Robert Muir Wood Categorical Data Analysis for Geographers and Environmental Scientists , Neil Wrigley     

胶州湾北部滨海湿地分布特征及质量评价

以胶州湾北部滨海湿地为研究区域,运用RS和GIS技术提取湿地信息,研究时空变化特征,建立湿地定量评价系统,并对湿地质量进行分析。研究表明,自1997年到2007年,该地湿地类型变化较大,沿岸湿地退化现象严重,人为活动影响增大,非湿地面积大量增加,湿地质量不断下降。