中国未来人口发展的粮食安全与耕地保障

中国人口发展的粮食安全与耕地保证程度研究表明,随着人口增长和消费扩张,中国未来的耕地规模和人均耕地面积会进一步下降,人均粮食消费水平和粮食需求总量将进一步提高;2020年在人均粮食420~435kg的消费水平上,基于18亿亩耕地保证的粮食生产能力可以基本满足14.36亿人口的粮食需求;在人均450kg的消费水平上,中国未来耕地的粮食生产能力足以支持人口高锋时间的14.73亿人,但受耕地资源有限约束,人均粮食占有水平很难有进一步提高。从耕地、粮食与人口关系看,中国未来人口的粮食安全必须向食物安全转变,从耕地资源约束的粮食生产与人口增长驱动的食物消费两端着眼:一方面要重视耕地与粮食安全——藏粮于土,全面提高土地资源综合生产能力;一方面要关注食物与消费安全——倡导适度消费,建立动植物并重型食物结构;从生产与消费两方面来认识和解决中国中长期人口发展的食物安全与耕地保障问题。     

人口与耕地和粮食问题探讨——天水市人口、耕地、粮食调查分析

人与耕地、粮食的关系十分密切。自从人类开发了土地资源,才有了人类社会。当今社会对人口的增长和粮食的增长给予同样重视每个国家、每个地区都力求生产更多更好的粮食,来促进人口在数量和素质上协调发展。在生活中人们全部所需能量中,88％的靠土地生产品提供,10％是靠草原和牧地供给,仅有2％的来自海洋。可见土地与粮食对人类生存和发展作常重要。解放以来,天水市由于对人口的增长控制不严,耕地减少严重,人口与耕地的矛盾日趋尖锐,人口已超过了土地承载能力,人口与粮食的发展失调。这种情况不但影响着人民生活小康水平的实现,子孙后代的幸福,而且影响着四化     

山东省人口多与耕地少的矛盾越来越尖锐

土地是人们赖以生存的立足之地,耕地则是人们取得粮食必不可少的最基本的生产资料。山东是我国人口最稠密的省份之一,也是人均占有耕地面积较少的省份之一。在人口总数越来越多,耕地面积越来越少的形势下,如何有效地控制人口增长,珍惜和合理利用每一寸土地,缓解人口多、耕地少的     

江西新余市人口与耕地矛盾调查

新余人口与耕地的矛盾是人口多、耕地少。大家都知道耕地是我们的宝贵财富,它是农业生产不可缺少的生产资料,是国民经济基础的基础。新余由于人口的高速增长,耕地面积越来越少。1949年解放时,新余总人口只有339700人,而耕地面积包括水田、旱地共1138259亩,人平耕地为3.35亩。为了扩大耕面积,增产粮食,党和政府曾动员农民开荒改地。到1957年,新余耕地面积增加到1186387亩。随着人口猛增和国家经济建设,开办工厂、修建道路、大修水利、农民建房等占用耕地的增加,到1966年,新余人口猛增到544345人,     

新疆塔里木河流域人口增长、水资源与沙漠化的关系

新疆塔里木河流域土地沙漠化的直接成因是干流和下游来水量的减少,而来水量的减少与上个流域段耕地面积的增加有密切关系。经过定性定量的分析,进一步发现在塔里木河这样典型的内陆河流域,人口增长对耕地面积(在干旱区流域基本等同于灌溉面积)不仅有密切的关系,而且不同的流域段人口增长对耕地增大的驱动效果也不同,人口增长的驱动对土地退化的影响具有从源流向下游的传递性,下游的土地沙化主要通过源流和上中游人口增长对下游来水量的影响传递产生。因此,治理下游严重的土地退化,控制源流和上中游的人口增长将比通过移民减少下游的人口更为重要。     

保护耕地资源,提高粮食供给能力——“人口——粮食”平衡关系的研究(二)

一、耕地是人们获得粮食的源泉提高粮食供给能力,满足人口对粮食的需求,一般说有四种途径:(1)土地或粮食生产资源的外延性扩大,(2)现时利用着的资源收获量的增加,(3)从其它国家进口的能力,(4)代替资源的开发(Ackerman 著:《人口、自然资源与技术》1967年,第88页)。第一,二种办法都属于在耕地上作文章。前者,是传统性方法,即力求扩大耕地面     

对人粮地矛盾的剖析与思考

人口与经济在相互制约和相互影响运动中,经常交替出现平衡与不平衡的现象。这在当前甘肃的反映是:人口增长过快,耕地面积锐减,粮食占有量的提高幅度滞后于人口和耕地的变化幅度,人粮地的矛盾越来越严峻。多方面的情况表明,研究甘肃这     

试论世界人口增长对耕地、粮食的影响及对策

试论世界人口增长对耕地、粮食的影响及对策秦品端俗话说：“民以食为天”。作为人口主食的粮食，依赖耕地生产。因而研究人口增长对耕地、粮食的影响及对策，以保障人口有较充足的粮食，使人口得以生存和发展，将是至关直要的世界性课题。一、世界人口增长对耕地的影响为...     

人口、耕地、粮食变迁启示录

我国素以农业大国著称于世.在不断深化改革的经济发展进程中,粮食生产也有了一定的发展.但随着人口的持续增加和耕地面积的不断减少,今后的粮食供求格局将会如何?这是各级领导和社会方方面面都很关心的问题.本文试就1978年以来的人口、耕地和粮食之间的辩证关系作一初步分析.     

论我国人口增长与粮食问题

论我国人口增长与粮食问题陈剑一、我国人口增长对粮食的压力人口与粮食的关系，实质上是粮食的供给与需求平衡的问题。一般认为，粮食需求量的增长主要来自以下两方面：一是新增人口对粮食的需求，二是现有人口生活水平提高的需要。中国是世界上人口最多的发展中国家。粮...     

Four theories of population change and the environment

Conclusion It is clear from the discussion of the four principal frameworks used to study population and land use that there is no consensus on the relationship. Most of the debate has centered on the two rivalpolicies of the neoclassical economists and the classical economists or natural scientists. Consensus has been difficult to reach mainly because the empirical evidence is weak and inconclusive, and the diverse experiences of different regions make it difficult to generalize for policy. Because the linkage is unclear, it seems premature to conclude that curbing population growth is the only or most important remedy for land degradation.It is relevant to note that this paper has focussed only on land degradation. It may be that population change plays a more conclusive role in affecting other aspects of the environment.The National Research Council is the operating arm of the National Academy of Sciences. The views expressed in this paper are solely those of the author.     

Water Resources,Land Exploration and Population Dynamics in Arid Areas - The Case of the Tarim River Basin in Xinjiang of China

Water resources are the root of life and development in arid areas like the Xinjiang Autonomous Region of China. In the Tarim Basin in Xinjiang, one of the driest places in the world, melting glaciers are the exclusive water source. Population growth, in particular in-migration, has greatly changed the ecological conditions of the Tarim River Basin in the past 2,500 years. Our research aims to study the interactions between population growth and changes in water and land resources, crossing the boundaries of the different reaches in the Tarim River Basin over the past 50 years. Time series data on population changes and economic development, water volume and quality, land use and land cover changes, and prevalence of morbidity relevant to water quality are collected to study the relationship between these factors. Adopting a statistical analysis and systems dynamics approach, we quantify the effect of population growth on water use and land degradation. ¹This paper results from the research project “Population changes and land degradation in Xinjiang of China,” funded by the Wellcome Trust Foundation (grant no. 065867). The authors appreciate the comments from the anonymous reviewers, and wish to extend thanks to the Asian MetaCentre for Population and Sustainable Development Analysis, and to Warren Sanderson, Wolfgang Lutz, Brenda Yeoh, Vipan Prachuabmoh, Min Weifang, Zheng Xiaoying, Brian O’Neill, Steve Hamburg, Laura Sadovnikoff, Verene Koh, and Sam Balakrishnan, for their invaluable support and help.     

Human population as a dynamic factor in environmental degradation

The environmental consequences of increasing human population size are dynamic and nonlinear, not passive and linear. The role of feedbacks, thresholds, and synergies in the interaction of population size and the environment are reviewed here, with examples drawn from climate change, acid deposition, land use, soil degradation, and other global and regional environmental issues. The widely-assumed notion that environmental degradation grows in proportion to population size, assuming fixed per capita consumption and fixed modes of production, is shown to be overly optimistic. In particular, feedbacks, thresholds, and synergies generally amplify risk, causing degradation to grow disproportionally faster than growth in population size. Based on a presentation to the Bixby Symposium on Population and Conservation, UC Berkeley, May 2006.     

Is it necessary to control the population growth of national minorities]

In the process of Socialist construction and modernization, the development of the population of national minorities deserves our attention because it is directly related to the economic and cultural development in the areas inhabited by such national minorities, and it has a great impact on the welfare and future of those people. Moreover, the population growth of the minorities is a key factor in the national population control strategy. A rapid population growth among the minorities has caused serious problems in distribution of farm land and food supply, low personal income, a rise in the unemployment rate, and a rise in the illiteracy rate. This has prevented a rise in the living standard among the minority population. In order to prevent and solve population problems among the minorities, we must take appropriate measures according to local conditions to control population increases. Through popularization of education, population growth may be put under control. For those people who volunteer to practice family planning, the government should provide all kinds of assistance. At the same time, an effort is needed to introduce the necessity of improving birth quality, to popularize new methods of child birth, and to develop health and medical care for the general public, so that the quality of the minority population may be gradually improved.     

The population,agriculture, and environment nexus in Latin America: country-level evidence from the latter half of the twentieth century

Unprecedented population growth and migration accompanied equally unprecedented land use and land cover change in Latin America during the latter decades of the twentieth century. Country-level data are examined with bivariate statistics to determine relationships between changes in population patterns and land use (agriculture and forest cover) from 1961 to 2001. In South America, large forest areas were eliminated during the period, while exceptionally high rates of forest clearing were ubiquitous in the Central America/Caribbean region. These environmental changes accompanied dissimilar initial population densities and different effects of population change on agriculture. While interacting with a host of political, socio-economic, and geographic processes, it appears that both Malthusian and Boserupian demographic processes were important drivers of deforestation. Given continued, though slowing, population growth, increased urban consumption, and future land use constraints, policy makers face myriad challenges in advancing sustainable agriculture-population dynamics in Latin America.     

我国人口-经济-二氧化碳排放的关联研究

通过全国1995～2008年各省区二氧化碳排放和人口发展状况对比发现,人口与二氧化碳排放之间并不呈现简单的正相关关系。本文引入经济系统对人口与二氧化碳排放之间的关系进行关联分析。研究发现,在短时期内,人口增长对二氧化碳排放的影响不可忽视,但从长远来看,经济增长对二氧化碳排放影响更为重要。值得注意的是,虽然人口和经济增长是二氧化碳排放变化的原因,但当滞后期延长,人口和经济系统之间将互为因果,使得人口和二氧化碳排放的关系将更为复杂。     

Causal Relationships among Population and Carbon Dioxide Emissions

The carbon dioxide emissions of the provinces would be calculated from 1995 to 2008.And we compare the provinces’ carbon dioxide emissions and population development.We found that the relationship between population and carbon dioxide emissions are not a simple correlation.In order to probe the relation,we introduce the economic variable into the research,take advantage the cointegration analysis and Granger causality test.The paper found that the population and economic growth is the main reason of carbon dioxide emission change.In short run the population growth would impact the carbon dioxide emissions,and increase in carbon dioxide emissions cannot be simply attributed to overpopulation,economic growth impact on carbon dioxide emissions more strongly.     

A Quantitative Investigation of the Population-Land Inequality-Land Clearance Nexus

This paper provides a quantitative investigation of the population-land inequality-land clearance nexus. Drawing on the literature on farmer optimization behaviour, the study formalizes and empirically tests a model of population-induced agricultural land clearance. The model makes several assumptions about this process: (a) The rate at which agricultural land is brought into production due to rising population pressures accelerates with the level of inequality in access to land, (b) Egalitarian systems have a greater capacity to absorb rising numbers of people per unit of land area and, thus, will have lower rates of agricultural land clearance than higher ones and (c) Irrespective of its degree of egalitarianism, the capacity of any system to hold people in one place will eventually break down once a critical population threshold is reached. Due to their lower population absorptive capacity, this level will be reached sooner under unequal systems of land distribution. Thus, the model also hypothesizes that the stimulatory impact of population growth on the demand for new land will exhibit a non-linear threshold pattern. For the farmer, the decision to clear a new plot of land will reflect these population-inequality interactions: Earnings from farming in settled areas will tend to fall as population densities and inequality in access to land increase. Time series results confirm that rural population growth is a significant factor driving agricultural land clearance in many of the 59 developing countries of our sample. Results also suggest that this rate of clearance is largest in countries with highly inegalitarian patterns of distribution. In contrast, cross-sectional regression results do not suggest any direct role for land inequality in population-agricultural land use outcomes. Contrary to the models assumption that this relationship should follow a non-linear threshold pattern, cross-sectional results also find no evidence that the absorptive capacity of highly densely populated land systems has been reached on average. However, they do provide support for an indirect linear relationship: Population induced agricultural land clearance is significantly magnified as inequality in access to land increases. Drawing on the empirics of the growth-inequality literature, the study suggests that this magnifying role may be linked to inequalitys impact on the assets of the poor. That is, by undermining the capacity of the rural poor to make productive investments in the land base, inequality in land distribution mediates population pressures in a way that affects both the quality and quantity of assets available to the poor to raise incomes, invest in skills accumulation, and spur demand in the rural economy as a whole.     

环境退化地区家庭人口对土地利用的影响研究——以中国西北毛乌素沙地为例

微观层面模型对于区分不同的人口群体以更好地明确环境退化的责任主体及其原因具有重要价值,对不同的土地利用方式进行经济区分是联接家庭人口特征与土地覆盖结果的重要手段。基于扩展的恰亚诺夫理论框架,文章利用2007—2008年两次调查所获293个农户样本数据,采用OLS和logit多变量模型实证分析毛乌素沙地家庭人口和其他因素对土地利用的影响。研究结果表明:(1)家庭人口因素对毛乌素沙地农户的土地利用产生重要影响;(2)毛乌素沙地主要土地利用的环境影响也遵循家庭生命周期的过程;(3)毛乌素沙地农户在减少有助于土壤修复利用活动的同时面临上升的退化风险。