等效沙厚度研究进展

风、沉积物和地表覆盖是控制沙丘地貌的三大要素.沉积物尤其是沙源供应对沙丘地貌的影响仍有待深入研究.沙丘体积的研究促使了等效沙厚度(equivalent sand thickness,EST)概念的提出.EST研究经历了多个沙丘和亚沙丘尺度2个研究阶段.多个沙丘EST研究发现,EST与沙丘高度之间具有较好的一致性,其与方...     

华南石炭纪中期白云岩地层分布及其形成模式

石炭纪是地质演化历史上重要的时期,发生了全球规模的海西造山运动,晚古生代大冰期（LPIA）达到峰值,全球海平面频繁波动,导致古气候和古环境的剧烈变化。在华南,石炭纪中期,浅水碳酸盐岩台地相区广泛发育一套白云岩沉积。本文系统总结华南3个主要碳酸盐台地内白云岩的厚度及时代,识别出白云岩时空分布的差异性。结合石炭纪中期全球气候环境特征,认为冰期兴盛引发了全球海平面下降,导致华南各沉积盆地形成利于白云岩化的环境,白云岩得以发育。而白云岩时空分布的差异性可能与各沉积盆地独特的构造演化以及不同成岩模式有关。中下扬子碳酸盐岩台地白云岩的形成模式主要为萨勃哈模式和成岩早期浅埋藏的渗透回流模式,形成相对较薄的白云岩沉积;中南部和西南部碳酸盐岩台地白云岩的形成模式为渗透回流模式,成岩规模较大,沉积较厚。     

Study of isotopic seasonality to assess the water source of proglacial stream in Chhota Shigri Glaciated Basin,Western Himalaya

The impact of surface melt patterns and the Indian summer monsoon (ISM) is examined on the varying contributions of end member (snow, glacier ice, and rain) to proglacial streamflow during the ablation period (June–October) in the Chhota Shigri glaciated basin, Western Himalaya. Isotopic seasonality observed in the catchment precipitation was generally reflected in surface runoff (supraglacial melt and proglacial stream) and shows a shift in major water source during the melt season. Isotopically correlated (δ¹⁸O–δD) high deuterium intercept in the surface runoff suggests that westerly precipitation acts as the dominant source, augmenting the other snow- and ice-melt sources in the region. The endmember contributions to the proglacial stream were quantified using a three-component mixing. Overall, glacier ice melt is the major source of proglacial discharge. Snowmelt is the predominant source during the early ablation season (June) and the peak ISM period (August and September), whereas ice melt reaches a maximum in the peak melt period (July). The monthly contribution of rain is on the lower side and shows a steady rise and decline with onset and retreat of the monsoon. These results are persistent with the surface melt pattern observed in Chhota Shigri glacier, Upper Chandra basin. Moreover, the role of the ISM in Chhota Shigri glacier is unvarying to that observed in other glacierized catchments of Upper Ganga basin. Thus, this study augments the significant role of the ISM in glacier mass balance up to the boundary of the central-western Himalayan glaciated region.     

Optimal lake-marsh pattern determination in lake-marsh systems based on the eco-hydrological processes management

The major hydrological factors in lake-marsh systems are water level (depth), water surface area, and water volume. The key index for determining the lake-marsh pattern is water level, which leads to the variation of lake-marsh patterns under natural hydrological alternations. In addition, the vegetation structure also affects the lake-marsh pattern. With socioeconomic development and climate change, the ‘land use’ and ‘water use’ competitions appear more seriously between a lake-marsh system and its surrounding socioeconomic system, also inside the lake-marsh system. The possible optimal lake-marsh pattern could solve the contradictions mentioned above. As few studies focus on this issue, this study proposed an optimal lake-marsh pattern determination method with eco-hydrological management on relieving the land use and water use competitions. The optimal lake-marsh pattern determination method considers the protection objects (water depth demands), water supply (precipitation, surface water, and groundwater), and water demand (especially evapotranspiration) in the system at annual and monthly scales. Calculation and analysis were performed for the optimal pattern of the Wolonghu Wetlands as an example. The results mainly showed that the lake-marsh pattern of the Wolonghu Wetlands cannot be achieved on meeting both the maximum ecological services values and minimum water shortage amount under present natural condition. With artificial regulation measures, the possible optimal annual lake-marsh patterns can be obtained based on both ecological and hydrological objectives, with the area ratio of lake and marsh in the range of 0.650:0.350 and 0.726:0.274, the corresponding water level of lake body was of 86.85 to 87.0 m. This study could provide references for the Wolonghu Wetlands management, also for similar lake-marsh systems and other ecological systems.     

BOOK REVIEWS

Books reviewed in this article: The Mexican Colonial Copper Industry. Elinore M. Barrett . The Control Revolution: Technological and Economic Origins of the Information Society . James R. Beniger . Land Degradation and Society . Piers M. Blaikie And Harold C. Brookfield , Eds . La carte, mode d'emploi. Roger Brunet . France: les dynamiques du territoire . Roger Brunet AND Jacques Sallois , EDS. At the Crossroads—The Mineral Problems of the United States . Eugene N. Cameron . A Census of One Billion People , Papers for International Seminar on China's 1982 Population Census. Li Chengrui , ED. Les Milieux “Naturels” du Globe . Jean Demangeot . The Geophysiology of Amazonia: Vegetation and Climate Interactions : Robert E. Dickinson , ED. Tenn-Tom Country . James F. Doster And David C. Weaver . Family Farming in Europe and America . Boguslaw Galeski And Eugene Wilkening , EDS. The Geography of Urban Transportation . Susan Hanson , Ed. Combating Desertification in Developing Countries . J. K. Jain , ED. Cartography in France—1660–1848. Science, Engineering and Statecraft . Josef W. Konvitz . Distribution of Distances in Pregeographical Space . Hans Kuiper . Physical Geography Lab Manual: A New Experimental Approach . Neal G. Lineback And John M. Harlin . Physical Geography: A Landscape Appreciation , 2nd ed. Tom L. Mc Knight . The Desert Is No Lady: Southwestern Landscapes in Women's Writing and Art . Vera Norwood And Janice Monk , EDS. France: A Geographical, Social, and Economic Survey . Philippe Pinchemel , translated, by D. Elkins and T. H. Elkins. Gene Banks and the World's Food . Donald L. Plucknett , Nigel J. H. Smith , J. T. Williams , And N. Murthi Anishetty . Latin American Development: Geographical Perspectives . David Preston , Ed. Making Sense of Development: An Introduction to Classical and Contemporary Theories of Development and Their Application to Southeast Asia . P. W. Preston . The History of the Countryside. Oliver Rackham . The Third World in Perspective . H. A. Reitsma AND J. M. G. Kleinpenning . The Industrial Geography of Australia . David C. Rich . The Recruiting Game , 2nd Ed., revised. John F. Rooney , JR. A Cultural Geography of North American Indians . Thomas E. Ross AND Tyrel G. Moore , EDS. Eastern Europe . Dean S. Rugg . Human Territoriality: Its Theory and History . Cambridge Studies in Historical Geography: 7. Robert David Sack . Experimental Fluvial Geomorphology . Stanley A. Schumm , M. Paul Mosley , AND William E. Weaver . The New Urban Landscape . David Schuyler . Atlas of American Women . Barbara Gimla Shortridge . Impacts of Hazardous Technology: The Psycho-Social Effects of Restarting TMI-1 . John Sorensen , Jon Soderstrom , Emily Copenhaver , Sam Carnes AND Robert Bolin . Modern Physical Geography , 3rd Ed., (Third Edition). Arthur N. Strahler AND Alan H. Strahler . India: Economic Resource Base and Contemporary Political Patterns . B. L. Sukhwal .     

不同选样方法对Pilgrim&Cordery设计暴雨雨型的对比研究

采用宜昌市主城区国家基本站长序列的逐分钟降雨过程资料,利用PilgrimCordery法(简称"PC法")比较通过自然降雨过程和最大历时过程两种降雨场次样本选样方法推求的设计暴雨雨型,并分析结果差异。结果表明:基于自然降雨过程和最大历时过程选样,利用PC法推求的宜昌市主城区短历时设计暴雨雨型基本都为单峰型,且雨峰均出现在整场降雨过程的前1/3时段。两种选样方法推求的短历时设计暴雨雨型的雨量分配比例存在较大差异,自然降雨过程选样推求的雨型雨峰峰值占总雨量的比例相较于最大历时过程的数值偏大,更为突出。实际工程设计中,设计师应当根据最大历时过程的选样规则进行推求,结合一定重现期下各个历时的降雨量值,进而得到各历时时程分配的具体雨强;计算得到宜昌市主城区重现期2a历时60、120、180 min的雨峰时段雨强分别为1.16、0.86、0.72 mm/min。     

2013年重庆秋季连阴雨期间暴雨过程对比分析

2013年8月29日9月11日,重庆各地出现不同程度的连续降水天气,持续614天,降水日数多、日雨量大,连阴雨期间重庆出现两次区域性暴雨天气过程,为较严重连阴雨天气。利用NCEP 1°×1°的再分析资料及重庆地区逐日、逐时降水资料及雷达回波资料,对连阴雨天气期间两次暴雨过程进行对比分析。结果表明：此次连阴雨过程中欧亚地区中高纬500 hPa呈“两脊一槽”型,连阴雨过程中两次暴雨过程的500 hPa中高纬形势有所不同,但影响系统均为短波槽;两次过程都存在强大的水汽输送带,因副热带高压位置不同,暴雨区水汽来源也不同,一次来源于南海,一次来源于南海与孟加拉湾。近地层弱冷空气及中层暖湿气流的持续影响使连阴雨天气得以维持,两次暴雨过程产生前或产生时都伴有低层冷空气和中层暖湿气流的加强。由于“9·10”暴雨过程在暴雨区附近有明显的θse锋区,而“9·2”暴雨却不存在θse锋区,因此连阴雨过程中两次暴雨的降水性质不同。在对流并不特别强的暴雨过程中,雷达资料对影响系统强度的判断同样有指导意义。     

Circulation Features Associated with the Record-breaking Typhoon Silence in August 2014

Climatologically, August is the month with the most tropical cyclone(TC) formation over the western North Pacific(WNP) during the typhoon season. In this study, the reason for abnormal TC activity during August is discussed—especially August 2014, when no TCs formed. The large-scale background of August 2014 is presented, with low-level large-scale easterly anomalies and anticyclonic anomalies dominating over the main TC genesis region, a weak monsoon trough system,and a strong WNP subtropical high(WPSH), leading to significantly reduced low-level convergence, upper-level divergence,and mid-level upward motion. These unfavorable large-scale conditions suppressed convection and cyclogenesis. In August2014, equatorial waves were inactive within the negative phase of the Madden–Julian Oscillation(MJO), with fewer tropical disturbances. Although the low-level vorticity and convection of those disturbances were partly promoted by the convective envelopes of equatorial waves, the integral evolution of disturbances, as well as the equatorial waves, were suppressed when propagating into the negative MJO phase. Moreover, the upper-level potential vorticity(PV) streamers associated with anticyclonic Rossby wave breaking events imported extratropical cold and dry air into the tropics. The peripheral tropospheric dryness and enhanced vertical wind shear by PV streamer intrusion combined with the negative MJO phase were responsible for the absence of TC formation over the WNP in August 2014.     

Predictable and Unpredictable Components of the Summer East Asia–Pacific Teleconnection Pattern

The East Asia–Pacific(EAP) teleconnection pattern is the dominant mode of circulation variability during boreal summer over the western North Pacific and East Asia, extending from the tropics to high latitudes. However, much of this pattern is absent in multi-model ensemble mean forecasts, characterized by very weak circulation anomalies in the mid and high latitudes. This study focuses on the absence of the EAP pattern in the extratropics, using state-of-the-art coupled seasonal forecast systems. The results indicate that the extratropical circulation is much less predictable, and lies in the large spread among different ensemble members, implying a large contribution from atmospheric internal variability. However,the tropical–mid-latitude teleconnections are also relatively weaker in models than observations, which also contributes to the failure of prediction of the extratropical circulation. Further results indicate that the extratropical EAP pattern varies closely with the anomalous surface temperatures in eastern Russia, which also show low predictability. This unpredictable circulation–surface temperature connection associated with the EAP pattern can also modulate the East Asian rainband.     

景观尺度、过程及格局（LSPP）研究的内涵及特点

景观尺度、过程与格局（LSPP）及其相互作用是景观生态学研究的核心内容。在分析景观尺度及效应、景观生态过程、景观格局及变化的基础上,凝练出了LSPP一体化理念的主要特征,并探索了LSPP中各要素之间的耦合关系。研究表明：LSPP一体化具有一定的理论价值,景观时空尺度是LSPP的重要基础,LSPP体现了景观过程及其生态效应。景观生态研究所涉及的结构、功能、动态与LSPP一体化等的理论与应用问题,随着新时代生态环境的复杂化,在情景模拟技术、大数据挖掘技术,以及生态物联网等技术支撑下,促进了景观生态学机理研究与应用范式的拓展与深化,对于当前区域发展与生态文明建设具有重要指导意义。