COMMENT ON “WHO WILL FEED CHINA”     

陈百明 《中国地理科学(英文版)》1997,(1)

I.MR.BROWN'SMAINOPINIONMr.LesterBrown,'presidentoftheWorldWatchinstituteintheU.S.A,publishedalongicicletitledas"WhowillfeedChina"in1994(Brown,1995),whicharousedgreatresponSeSfromhomeandabroadandattractedmuchattentionfromallsides.Theadnideasofthearticleincludethefollowingthreepoints:(1)ItisestimatedthatthepopulationofChinawillincrare490whitionfrom1990tO2030,uptol,600whition;thecultivatedlandofChinaisaffectedbythemedeAnzationoftheeconomy,andisevendisap~ng;inaddition,thepotentiality…  相似文献   

BOOK REVIEWS     

《The Professional geographer》1987,39(1):94-129

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   

云南省怒江傈僳族自治州的人口问题     

周定一 《山地学报》1989,(2)

1964年以来,怒江傈僳族自治州人口增长与经济发展失调,由此而造成诸多社会-经济矛盾,严重妨碍着当地的发展。为改变现状,兹建议:完善和认真执行少数民族地区的计划生育政策,并由政府给予少量资助,在州内或向州外进行适量的人口迁移,以缓和人口压力,促进经济发展。  相似文献   

Regional Comparisons of Metropolitan and Nonmetropolitan Migration in the 1970s and 1980s: Age and Place Implications*     

Peter B. Nelson  Adam Sewall 《The Professional geographer》2003,55(1):83-99

Over the last thirty years, nonmetropolitan regions across the United States have experienced volatile population shifts ranging from rapid growth to persistent decline. Several authors have suggested that the age structure of the population may contribute to these population trends. In the 1970s, the older baby boomers were entering labor and housing markets, while the younger boomers were enrolling in nonmetropolitan colleges and universities. By the 1980s, this large cohort was aging into a different stage in the life course. This article examines metropolitan and nonmetropolitan population shifts during the 1970s and 1980s within an age‐cohort framework. Using Public Use Microsample data from 1980 and 1990, the analysis explores relationships between housing market, labor market, place characteristics, and the migration flows of different age cohorts. The analysis focuses on cohort‐specific in‐migration to two regions: New England and the Four Corners states of Utah, Colorado, Arizona, and New Mexico. The results are consistent with a life‐course understanding of migration behavior, especially during the late 1970s, with older cohort shifts directed towards nonmetropolitan destinations and younger cohort shifts more influenced by labor and housing‐market variables. The results further demonstrate a large potential for future nonmetropolitan population growth, yet these growth experiences are likely to be regionally differentiated. These results have important policy implications for nonmetropolitan regions.  相似文献   

沙坡头地区人工植被油蒿种群结构与更新的研究   总被引：7，自引：7，他引：7  

马凤云  李新荣  龙利群  张景光 《中国沙漠》2002,22(6):571-575

采用野外调查和比较分析的方法,对沙坡头地区人工植被油蒿种群的结构和更新进行了研究.通过对不同固沙起始年代油蒿种群大小结构的分析发现,幼树个体的数量较多,中等大小的成年个体数量少,老龄个体的数量极少.年限较短的人工植被区油蒿幼树个体的数量多于年限较长的人工植被区,而油蒿幼苗的数量则呈相反的趋势.油蒿幼苗在不同的地形中分布数量也不同,丘间地有较多的幼苗,背风坡幼苗特别少.油蒿成年个体在人工植被区中呈均匀分布,油蒿幼苗则呈聚集分布.  相似文献   

南极长城站和中山站贼鸥种群生态学比较研究          下载免费PDF全文

王自磐 《极地研究》2002,14(2):83-92

对南极长城站和中山站两地的贼鸥种群进行包括营巢行为、觅食习性、种群变化、繁殖生态 ,以及贼鸥栖息地的地理和生态环境等的比较研究 ,结果表明两地贼鸥种群存在明显的生态学差异。这种差异不仅反映了贼鸥的生态习性与栖息地自然环境和生态结构的密切相关性 ,更体现了该种海鸟对南极不同生存环境极强的适应能力。人类活动以及贼鸥对人类废弃食物的依赖 ,在一定程度上改变动物食物结构 ,并对贼鸥生态习性乃至种群数量变化均产生一定影响。两地贼鸥种群通过改变觅食对策和调整产卵、孵化时间和延长育雏期等 ,达到对不同地理纬度和气候条件的适应 ,确保物种的延续  相似文献   

北京丰台区农村居住用地变化及与人口相关模型   总被引：12，自引：1，他引：12  

徐勇  沈洪泉  甘国辉  郭腾云 《地理学报》2002,57(5):569-576

采用GIS技术和统计分析技术，基于1984年，1992年，1996年和1999年4期土地利用图件和数据，分析了1984－1999年期间北京丰台区农村居住用地变化过程及地域分异特征；提出并应用特征均值探讨了农村人均居住用地和人居密度变化的过程和趋势，以行政村为基本单元，利用1999年农村居住用地数据与对应的农村人口数据建立了表达式为Sv=11.324e^0.0006pv的农村居住用地与人口相关模型；用1992年数据对模型进行检验和误差分析的结果表明，模型适用地域为北京近郊且不邻近卫星城镇的农村区。  相似文献   

Bisexual populations of the brine shrimpArtemia in Sète-Villeroy and Villeneuve Saltworks (Languedoc,France)     

Alain Thiéry  Florence Robert 《International Journal of Salt Lake Research》1992,1(1):47-63

So far,Artemia populations in solar saltponds of southern France have been considered as belonging to the Old World parthenogenetic strain. However, two populations sampled monthly in abandoned salinas of Sète-Villeroy and Villeneuve appear to be bisexual throughout their life-cycle. Their sex ratio regularly fluctuates near equilibrium, and mating, present throughout life, is very common in early winter. Morphological characteristics, particularly the male frontal knobs structure, are discussed in relation to the diploid bisexual Mediterranean strain,Artemia tunisiana, which is distributed around the Mediterranean basin. The existence of sexual populations is discussed in regard to variation in environmental conditions in abandoned salinas.  相似文献   

Comparisons of two global built area land cover datasets in methods to disaggregate human population in eleven countries from the global South     

Forrest R. Stevens  Andrea E. Gaughan  Jeremiah J. Nieves  Adam King  Alessandro Sorichetta  Catherine Linard 《International Journal of Digital Earth》2020,13(1):78-100

ABSTRACT

Mapping built land cover at unprecedented detail has been facilitated by increasing availability of global high-resolution imagery and image processing methods. These advances in urban feature extraction and built-area detection can refine the mapping of human population densities, especially in lower income countries where rapid urbanization and changing population is accompanied by frequently out-of-date or inaccurate census data. However, in these contexts it is unclear how best to use built-area data to disaggregate areal, count-based census data. Here we tested two methods using remotely sensed, built-area land cover data to disaggregate population data. These included simple, areal weighting and more complex statistical models with other ancillary information. Outcomes were assessed across eleven countries, representing different world regions varying in population densities, types of built infrastructure, and environmental characteristics. We found that for seven of 11 countries a Random Forest-based, machine learning approach outperforms simple, binary dasymetric disaggregation into remotely-sensed built areas. For these more complex models there was little evidence to support using any single built land cover input over the rest, and in most cases using more than one built-area data product resulted in higher predictive capacity. We discuss these results and implications for future population modeling approaches.  相似文献   

蓝致密星系的星族合成     

程福臻  孔旭 《紫金山天文台台刊》1999,18(3):274-278

介绍了简单星族的定义和星族合成方法;简述了蓝致密星系的观测特征和研究意义;列出了我们利用北京天文台２ ．１６ ｍ 望远镜已成功观测蓝致密星系样本。在此基础上,我们运用恒星团星族合成方法,分析了一些蓝致密星系的光学谱。给出了它们中年龄和金属丰度不同的星族对星系５８７ｎｍ 处连续谱流量贡献的百分比;同时还给出星系内部恒星形成的历史和内红化值。  相似文献