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1.
环境变化对黄河下游来水来沙的影响   总被引:5,自引:0,他引:5  
本文探讨了到下世纪中叶时,由于环境变化对黄河下游来水来沙的影响,考虑了三方面的因素,即:全球性变暖,温度、降水、径流和泥沙的长周期变化,和人类。最后得出,届时来水来沙将分别比目前减少19%-29.6%和增减+26.3%--34.0%。  相似文献   

2.
珠江口红树群落钙的累积和循环研究   总被引:1,自引:0,他引:1  
在测定珠江口红树群落生物量和生产力的基础上,进一步测定红树群落各组分的钙含量,计算群落钙的贮量、年存留量、年归还量、年吸收量、周转期和富集经,以了解珠江口红树群落钙元素的累积和循环状况。结果表明,珠江口5个红树群落钙的贮存总量为197-640.1kg/hm^2,平均为382.4kg/hm^2。年存留量为20.3-58.6kg/hm^2.a,平均为39.3kg/hm^2.a;年归还量为24.1-75.5kg/hm^2.a,平均为44.9kg/hm^2.a;年吸收量为44.4-134.1kg/hm^2.a,平均为84.2kg/hm^2.a;周转期为7-10a,平均8a;存留率为43.7%-52.7%,平均46.7%,归还率为47.3%-56.3%,平均53.3%。乔木型红权群群落有较高的存留率和较低的归还率。  相似文献   

3.
周兆德  郑剑非 《地理学报》1989,44(4):407-419
本文从海南热带作物生物特性、现实生产结构和地区气候条件出发、对热作种植业进行了模湖区域性划分;在计算构成各区产量基本参数的基础上,应用多目标规划方法,建立了热作结构优化的近期分区模型;并通过近期基础模型和对未来参数的预测,建立了远期灰色规划模型。结果表明,近期方案可提高收益5.1-55.7%,远期方案可提高54-90%,远近期方案均取得了明显的经济效果。  相似文献   

4.
李玉祥 《自然资源》1993,11(5):75-79
砂生槐是藏南河各地带分布极广的一种多年生豆科灌木,具有极强的抗旱,耐瘠,抗风沙等生态适应性。目前当地群众挖其植株作为生活燃料,嫩枝叶或干叶为牲畜放牧和越冬饲料,破坏相当严重。为充分开发其利价值,首次取其不同时期嫩枝和种子进行营养成份分析,发现其富含蛋白质16.82-30.60%;脂肪1.60-9.39%;17种氨基酸含量达16.13-24.53%;除色氨酸未能测量外,其余7种必须氨基酸含量均高于…  相似文献   

5.
盐湖形成过程中银的迁移形式及富集条件   总被引:1,自引:1,他引:1  
郑大中 《盐湖研究》1994,2(2):28-35
本文研究了盐湖形成过程中银的迁移形式及富集条件.在热液中银主要以Ag(HS) ̄-_2·Ag(NH3)·AgCl络合物形式迁移;在表生条件下银主要以Ag(S2O3)络合物形式迁移.它们在盐湖中被演化为AgCl络合物,由于湖水大量蒸发、盐类大量结晶析出,导致盐湖卤水中银的富集.  相似文献   

6.
试论第四纪晚期中国古人类三次迁移与气候变化   总被引:6,自引:1,他引:6  
陆巍  吴宝鲁 《地理学报》1997,52(5):394-402
本文整理了旧石器晚期以来石陶文化的特征,提出了一个“第四纪晚期中国古人类三次迁移”猜想,即五万年以来中国古文化发生过三次南北大融合;第一次,50kaBP-40kaBP,南民北移;第二次,18kaBP-13kaBP,北民南移;,第三次,10kaBP-8.3kaBP,南民又北移,成为中原新石器文化的南源;以瓦皮岩人迁到关中为典型,促进了中原新石器文化的敏荣和中华文明的兴起。  相似文献   

7.
针对燕山东段土石山区黄绵土坡耕地面积较大,水土流产严重且许多地方不便梯地建设等现实情况,在滦平试区进行了秋季免耕的试验研究,结果表明,玉米地免去秋耕,比对照区减少土壤冲刷量79.3%,减少地表径流量18.8%,土壤水分提高1%左右,土壤碱解氮和速效磷分别提高1.4ppm和38.7ppm产量提高2%-10%,每公顷节省耕作费用150-225元,具有良好推广前景。  相似文献   

8.
藏北高原地气之间的水分循环   总被引:12,自引:7,他引:12  
利用GAME-Tibet期间所取得的高分辨率土壤温度、含水量以及降水量资料,对藏北高原地气之间的水分循环过程进行了分析。结果表明,唐古拉山以南平坦地表7-8月份地表蒸发的水汽量可达177.1mm,占同期降水量的73.2%;唐古拉山以北平坦地表7-8月份地表蒸发的水汽量可达73.3mm,占同期降水量的57.7%。地表土壤通过蒸发不但将大量的水分输送给其上的大气,而且将热量传给了其上的大气,从而抑制了土壤温度的升高。如果仅就唐古拉山南北地表蒸发而言,引起其较大差异的原因主要是降水量的不同。  相似文献   

9.
迁移八律与中国人口迁移   总被引:3,自引:0,他引:3  
中国人口迁移具有下列八个特征:1,提高生活质量是经济目的迁移的主要原因,非经济目的迁移违反经济规律时不能巩固;2,在城市化过程中,乡村迁往城市是主要迁移方向;3,整体男性迁移多,轻工劳务和婚姻迁移突出地区女性迁移多;4,独身青年迁移多;5,短距离迁移多,高素质人口迁移距离较长;6,迁移有圈层递补现象;7,强迁移方向必然带来较弱的迁移回流,当两地经济势能接近和递转时,回流加强;8,城市化过程中大城市迁入人口比重大,吸引迁移的范围广。可见,列文斯坦提出的人口迁移规律基本上适合中国的实际,中国人口迁移的实际又丰富了列文斯坦的人口迁移规律。  相似文献   

10.
紫色丘陵区典型小流域氮素迁移及其环境效应   总被引:17,自引:0,他引:17  
选择四川盆地中部紫色土丘陵区典型小流域,通过2002~2004年3 a对主要土地利用地类氮素流失、小流域地表水和井水氮素迁移形态、途径与通量的连续观测,研究非点源氮素的来源、去向、迁移特征及其环境效应。结果表明,紫色土坡地氮素主要通过径流与泥沙迁移,坡耕地、居民点氮素流失是小流域非点源氮的主要贡献者,其氮素流失负荷分别为150.4kg、73.84 kg,占小流域氮素迁移总负荷的52.4%、25.7%;紫色丘陵区小流域地表水已呈现明显氮索富营养化特征,地下水硝酸盐污染较为严重,应重视该地区非点源污染控制;小流域氮素迁移的尺度差异明显,坡地以颗粒态氮为主,小流域以硝酸盐为主,氮素迁移的尺度效应可能导致非点源氮污染的异地效应,从而加剧长江三峡水体富营养化压力。  相似文献   

11.
BOOK REVIEWS     
Book Reviewed in this article: Development and Environment in Peninsular Malaysia . S. Robert Aiken, Colin H. Leigh, Thomas R. Leinbach, Michael R. Moss. The Rural-Urban Fringe: Canadian Perspectives . Ken B. Beesley and Lorne H. Russwurm, eds. Women and Development . Lourdes Benería, ed. The Border that Joins: Mexican Migrants and U.S. Responsibility . Peter G. Brown and Henry Shue, eds. Cities of the World: World Regional Urban Development . Stanley D. Brunn and Jack L. Williams, eds. Time Resources, Society, and Ecology: On the Capacity for Human Interaction in Space and Time (Vol. I, Preindustrial Societies). Tommy Carlstein. Urban Geography . David Clark. Spanish City Planning in North America . Dora P. Crouch, Daniel J. Garr, and Axel I. Mundigo. Not On Our Street: Community Attitudes to Mental Health Care . M. J. Dear and S. M. Taylor Unequal growth: Urban and Regional Employment Change in the U.K. Stephen Fothergill and Graham Gudgin. Agricultural Land in an Urban Society . Owen J. Furuseth and John T. Pierce. The Petroleum Industry in Oil-Importing Developing Countries . Fariborz Ghadar. Historical Understanding in Geography, An Idealist Approach . Leonard Guelke. Regional Planning in Europe . R. Hudson and J. R. Lewis, eds. Remote Sensing for Resource Management . Chris J. Johannsen and James L. Sanders, eds. Geography and The State . R. J. Johnston. Texas Graveyards: a Cultural Legacy . Tlrry G. Jordan. The Politics of Location: An Introduction . Andrew Kirby. A Social Geography of the City . David Ley. Energy and the Future . Douglas MacLean and Peter Brown, eds. The Natural Environment of Newfoundland Past and Present . A. G. Macpherson and J. B. Macpherson, eds. Tourism: Economic, Physical and Social Impacts . Alister Mathieson and Geoffrey Wall. Railroads and Land Grant Policy: A Study in Government Intervention . Lloyd J. Mercer. Progress in Rural Geography . Michael Pacione, ed. Progress in Urban Geography . Michael Pacione, ed. Models of Spatial Inequality: Settlement Patterns in Historical Archaeology . Robert Paynter. Natural Hazard Risk Assessment and Public Policy, Anticipating the Unexpected . William J. Petak and Arthur A. Atkisson. The Nature of Geomorphology . Alistair F. Pitty. Regional Conflict and National Policy . Kent A. Price Women and Spatial Change: Learning Resources for Social Science Courses . Arlene C. Rengert and Janice J. Monk, eds. Urban and Regional Analysis for Development Planning . Richard Rhoda. Rivers: Form and Process in Alluvial Channels . Keith Richards. This Remarkable Continent: An Atlas of United States and Canadian Society and Culture . John F. Rooney, Jr., Wilbur Zelinsky, and Dean R. Louder, gen. eds. The Origins of Open-Field Agriculture . Trevor Rowley, ed. Residential Location Determinants of the Older Population . Gundars Rudzitis. Borderland Sourcebook: A Guide to the Literature on Northern Mexico and the American Southwest . Ellwyn R. Stoddard, Richard L. Nostrand, and Jonathan P. West, eds. Arctic and Antarctic . David Sugden. Tall Timbers Ecology and Management Conference, February 22–24, 1979, Proceedings No. 16 . Graphic Communication and Design in Contemporary Cartography (Progress in Contemporary Cartography , Vol. II). D. R. Fraser Taylor, ed. Living with Energy Shortfall: A Future for American Towns and Cities . Jon Van Til. The United States: Habitation of Hope . J. Wreford Watson. Air Photo Interpretation for Archaeologists . D. R. Wilson. Urban and Rural Change in West Germany . Trevor Wild, ed. Population and Resources . Harry Robinson.  相似文献   

12.
BOOK REVIEWS     
Book Reviewed in this article: Geography and the Third World. International Seminar, 14–18 May 1980, Kuala Lumpur, Malaysia . Ishmail Ahmad and Jamaluddin Md Jahi, eds. The Growth Dilemma: Residents' Views and Local Population Change in the United States . Mark Baldassare. Sport and Place: A Geography of Sport in England, Scotland & Wales . John Bale. The Deindustrialization of America: Plant Closings, Community Abandonment, and the Dismantling of Basic Industry . Barry Bluestone and Bennett Harrison. Selected Essays 1963–1975: Carl O. Sauer . Bob Callahen, ed. Housing and Planning in the Countryside . G. Clark. Conflict, Politics and the Urban Scene . Kevin R. Cox and R. J. Johnston, eds. Thematic Maps: Their Design and Production . David J. Cuff and Mark T. Mattson. Wine: A Geographic Appreciation . Harm Jan de Blij. USSR in Maps . J. C. Dewdney. Political Geography: A Contemporary Perspective . Ramesh D. Dikshit. Rethinking Human Adaptation . Rada Dyson-Hudson and Michael A. Little, eds. Sacred Sands: The Struggle for Community in the indiana Dunes . J. Ronald Engel. Geography of the Biosphere . A. Furley and Walter W. Newey. Disaster and Reconstruction . Robert Geipel. Glasgow: The Making of a City . Andrew Gibb. Design for Arid Regions . Giden S. Golany, ed. Urbanization and Cancer Mortality: The United States Experience, 1950–1975 . Michael R. Greenberg. Geology in the Nineteenth Century: Changing Views of a Changing World . Mott T. Greene. Colonización y Destrucción de Bosques en Panamá . Stanley Heckadon Moreno and Alberto McKay, eds. Urban Geography: A First Approach . David T. Herbert and Colin J. Thomas. The Visual and Spatial Structure of Landscapes . Tadahiko Higuchi. Climate from Tree Rings . M. K. Hughes, P. M. Kelly, J. R. Pilcher, and V. C. LaMarche, Jr., eds. The structure of Nineteenth Century Cities . James H. Johnson and Colin G. Pooley, eds. The American Planner: Biographies and Recollections . Donald A. Krueckeberg, ed. Urban Land Policy For the 1980s, the Message for State and Local Government . George Lefcoe, ed. Regional Planning: Evolution, Crisis and Prospects . Gill C. Lim, ed. Relevance and Ethics In Geography . Bruce Mitchell and Dianne Draper. China: The Geography of Development and Modernization . Clifton W. Pannell and Laurence J. C. MA. The Urban Retailing System . Robert B. Potter. Hants. Nonconventional Energy Resources . Philip R. Pryde. Caribbean Migrants: Environment and Human Survival on St. Kitts and Nevis . Bonham C. Richardson. Population and Resources . Harry Robinson. East Los Angeles: History of A Barrio . Ricardo Romo. Integrated Impact Assessment . Frederick A. Rossini and Alan L. Porter, eds. Environmental Aesthetics: Essays in Interpretation . Barry Sadler and Allen Carlson, eds. Earthwatch . Charles Sheffield. Field Techniques and Research Methods in Geography . Robert H. Stoddard. Haiti: Land of Poverty . Robert J. Tata. Weathering and Erosion: Sources and Methods in Geography . Stephen T. Trudgill. Once Beneath the Forest. Prehistoric Terracing in the Río Bec Region of the Maya Lowlands . B. L. Turner, II. The Historical Geography of Scotland since 1707 . David Turnock.  相似文献   

13.

Reviews of geographic software in this article:

DEMO-GRAPHICS: WORLD POPULATIONS AND PROJECTIONS.

ESP

GAUSS.

CEMODEL S. Damus

LIMDEP. William H. Greene

MICROSTAT 4.1

OTIS

PCIPS. (Personal Computer Image Processing System). H.J. Meyers and R. Bernstein.

REGRESSION ANALYSIS OF TIME SERIES (RATS)

SPSS/PC+

URBAN DATA MANAGEMENT SOFTWARE (UDMS)  相似文献   

14.
Desertification is a global phenomenon that affects about two billion people. It occurs in arid zones where the annual precipitation is below 400 mm, partic- ularly in the marginal areas of the world's largest deserts. It is a result of water and wind erosion, over- grazing, global warm-ing, improper soil cultivation, and increased pressure ot population growth, and it causes degradation of soil and natural and agricultural vegetation. The direct result is less food for people and livestock, which influences pop- ulation and animal husbandry fluctuations. Despite ef- forts to combat and reduce desertification, the affected areas are annually increasing.  相似文献   

15.
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   

16.
BOOK REVIEWS     
Book Reviewed in this article: The Rice Economy of Asia . Randolph Barker and Robert W. Herdt with Beth Rose. Using Microcomputers: A Guidebook for Writers, Teachers, and Researchers in the Social Sciences . Blaine A. Erie—the Lake that Survived . Noel M. Burns. Geology and Society . Donald R. Coates. Caves and Karst of Kentucky . Percy H. Dougherty, ed. Altered Harvest: Agriculture, Genetics, and the Fate of the World's Food Supply . Jack Doyle. The Middle East and North Africa, A Political Geography . Alasdair Drysdale and Gerald H. Blake. Clamor at the Gates. The New American Immigration . Nathan Glazer, ed. Development and the Landowner: An analysis of the British experience . Robin Goodchild and Richard Munton. Discovering Landscape in England and Wales . Andrew Goudie and Rita Gardner. The Modern Plantation in the Third World . Edgar Graham and Ingrid Floering. Social Relations and Spatial Structures . Derek Gregory and John Urry, eds. The World Food Problem 1950–1980 . David Grigg. Costa Rica: A Geographical Interpretation in Historical Perspective . Carolyn Hall. The Urbanization of Capital: Studies in the History and Theory of Capitalist Urbanization . David Harvey Consciousness and the Urban Experience: Studies in the History and Theory of Capitalist Urbanization . David Harvey. Reviving Main Street . Deryck Holdsworth, ed. Rural Roads and Poverty Alleviation . John Howe and Peter Richards, eds. Uneven Development in Southern Europe: Studies of Accumulation, Class, Migration and the State . Ray Hudson and Jim Lewis, eds. Karst Geomorphology . J. N. Jennings. The Geomorphology of North-west England . R. H. Johnson, ed. Climate Impact Assessment: Studies of the Interaction of Climate and Society . Robert Kates, Jesse Ausubel, Mimi Berberian, eds. Public Service Provision and Urban Development . Andrew Kirby, Paul Knox, and Steven Pinch, ed. State and Market: The Politics of the Public and the Private . Jan-Erik Lane, ed. Living Cities . Twentieth Century Fund Task Force on Urban Preservation Policies. World Climatic Systems . John G. Lockwood. Urban Ethnicity in the United States. New Immigrants and Old Minorities . Lionel Maldonaldo and Joan Moore, eds. Culture and Conservation: The Human Dimension in Environmental Planning . Jeffrey A. McNeely and David Pitt, eds. The Andean Past. Land, Societies, and Conflicts . Magnus Mörner. Gaia: An Atlas of Planet Management . Norman Myers, ed. Progress in Industrial Geography . Michael Pacione, ed. Progress in Political Geography . Michael Pacione, ed. Rivers and Landscape . Geoff Petts and Ian Foster. Urbanization and Planning in the 3rd World: Spatial Perceptions and Public Participation . Robert B. Potter. One Island, Two Nations? A Political Geographical Analysis of the National Conflict in Ireland . D. G. Pringle. Circulation in Third World Countries . R. Mansell Prothero and Murray Chapman. The Ozarks Outdoors: A Guide for Fishermen, Hunters, and Tourists . Milton D. Rafferty. Suburban Burglary: A Time and a Place for Everything . George Rengert and John Wasilchick. Geomorphology and Soils . K.S. Richards, R.R. Arnett, and S. Ellis, eds. The Homes and Homeless of Post-War Britain . Frederick Shaw. Indochinese Refugees in America . Paul J. Strand and Woodrow Jones, Jr. Wild Horses and Sacred Cows . Richard Symanski. Forever Wild: Environmental Aesthetics and the Adirondack Forest Preserve . Philip G. Terrie. The Regional Economic Impact of Technological Change . A.T. Thwaites and R.P. Oakey, eds. The Good Life . Yi-Fu Tuan.  相似文献   

17.
Reviews of geographic software in this article: DEMO-GRAPHICS: WORLD POPULATIONS AND PROJECTIONS. ESP GAUSS. CEMODEL S. Damus LIMDEP. William H. Greene MICROSTAT 4.1 OTIS PCIPS. (Personal Computer Image Processing System) . H.J. Meyers and R. Bernstein. REGRESSION ANALYSIS OF TIME SERIES (RATS) SPSS/PC+ URBAN DATA MANAGEMENT SOFTWARE (UDMS)  相似文献   

18.
19.
《寒旱区科学》2014,(4):I0002-I0003
1. Aims and scope
Sciences in Cold and Arid Regions (SCAR) is a bimonthly journal that publishes in English the latest research achievements in processes and the pattems of the Earth surface system in cold and arid regions. Researches in cold regions emphasize particularly on the cold-region-characterized physical,  相似文献   

20.
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