中国西北地区人口增长对土地退化的驱动作用分析

文章通过定性定量分析西北地区人口增长与粮食生产系统和土地压力响应之间的相关关系,发现人口的增长主要与耕地面积的扩展有较强相关性,与单位粮食亩产增加等变量指标的关系较弱。进一步分析发现,即便是在人口增长与耕地扩大的关系中,实际的耕地增长和粮食需求也远远大于实际人口增长的需求,由此可以看到在西北地区粮食生产和耕地面积扩大的过程中,人口增长并不如人们一般认为的那样大,人口增长对土地退化只能承担一部分责任,不构成最重要的原因。     

试析当代中国土地制度对人口生育的影响

本文着重探讨中国土地制度是否是人口增长的一个内生变量,以及它在影响人口增长的诸因素中所占有的份量。文章首先概述了集体化时期的“三级所有,队为基础”的土地制度以及按人口平均分配口粮的模式对人口增长的刺激作用;接着分析了1978年农村改革以后所实行的土地制度,由于只是将农民在集体生产队时期对集体土地的收益和福利均分权,显化为对土地的均分权,这样,土地公有刺激人口增长的机制继续保留。为了检验“增人不增地、减人不减地”的新制度安排对人口的影响,利用笔者对贵州省湄潭试验区的调查资料,揭示出这一制度对人口增加户、不变户和减少户的不同影响,以及它对降低农民生育愿意所起的作用。     

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     

浅谈当前我国农业人口过剩

我国80％以上的人口在农村,比重之大为世界所少有。而且我国农业人口基数大,特别是建国以来发展速度惊人。1979年同1949年相比,我国的农业人口增长了81.9％,而耕地面积不但没有增加,反而有所减少。我国可用于农、林、牧业的土地面积大约有66.5亿亩,占     

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     

湘江流域人口分布空间演化特征分析

人口发展与资源、环境协调问题成为当前湘江流域综合开发与管理中引人关注的焦点。采用1993也009年《湖南省统计年鉴》数据,运用密度分析、不均衡指数法、重心分析以及偏移-分享分析方法,研究20世纪90年代以来湘江流域地区人口空间分布演化的特征和规律。研究结果表明。湘江流域人口分布具有“先分散后集聚”的特点。人口分布重心在东北-西南方向往返移动。人口偏移增长在不同区域层面具有阶段性特征。人口具有向各地级市市辖区集聚的特点。社会经济发展是湘江流域人口分布空间演化的主要驱动机制．区域人口发展政策强化了人口分布空间演化过程．     

区域人口城镇化多维特征对居民电力消费的驱动影响——基于浙江省分县数据的实证研究

人口城镇化是能源消费和碳排放增长最重要的驱动因素之一,也是居民电力消费增长的核心驱动因素.以往的研究仅考虑人口城镇化水平的影响,忽略了人口城镇化的异质性模式的影响,且对低层次空间单元的关注不够.文章集成浙江省2000年和2010年分县数据,将区域人口城镇化特征分解为水平、形态、结构和阶段,利用固定效应模型分析其对居民电力消费的驱动影响.结果发现:区域人口城镇化水平提高、形态紧凑化、结构本地化、发展阶段高端化、平均家庭户规模缩小、劳动参与率降低对居民电力消费有着显著的驱动影响,而户均房间数减少则有抑制作用.未来新型城镇化应规范人口城镇化水平的统计标准,提倡紧凑型人口城镇化形态,协调人口城镇化和土地城镇化,加强电力配套保障.     

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。     

北京近郊区的农业人口与耕地问题

北京近郊农业地区人多耕地少,过去由于农业人口增长控制不严,城乡建设占地规模不断扩大,出现了人口大量增长,而耕地面积大幅度减少的严重局面。这个问题,在我国的大中城市带有普遍性。耕地减少,不但影响到整个城市的蔬菜及其它副食品供应,同时还出现了农村新增劳动力安置困难的问题。作为首都,应认真总结这方面的历史经验教训,采取相应的对策,把近郊农业地区建设得更好。 一、耕地面积大幅度减少的直接原因是城乡占地规模的不断扩大     

青海湖区人口状况考察及政策建议

鉴于青海湖区面临湖水水位持续下降、湿地面积逐年萎缩、土地沙化和草地退化日趋严重、生物多样性受到严重威胁等问题,本文从人与自然协调发展的角度,结合青海省正在争取实施的《青海湖流域生态环境保护与综合治理规划》项目,通过青海湖区人口承载能力的测算和未来人口发展趋势的预测,提出“保护青海湖生态环境应统筹解决人口问题”的观点,并从人口变动方面提出了统筹解决青海湖区人口问题的对策建议。     

An outline of study on China's population / environment issues

Attention is given to population and growth and the impact on the environment and resources in China. Policies for managing the environment and instituting population education are also addressed. The first position paper of the National Environmental Protection Agency (NEPAC) on June 2, 1990 is summarized. The population of China was 1.11 billion in 1989. The rate of growth in 1988 was 14.2/1000 in 1988. 91% live in the southeast on 43% of the land. Land area is 9.6 million square miles. 65% can be made arable, and 14% is cultivated. China has 7% of the world's arable land and 20% of the world's population. Population growth has reduced arable land/captia. The impact on forests has been deforestation. 13% of land is currently forested, and timber reserves encompass 9.14 billion cubic meters, or 9 cubic meters/person. The demand for firewood and timber will increase. The impact on grasslands has been overgrazing and desertification at a current rate of 1560 square kilometer/year. The impact on energy resources is a greater demand for coal which will increase and thus increase pollution of the environment. The impact on water resources is greater demand and increased pollution. Water resources are 2700 cubic meters/person or less than the world average. 26.8 billion tons of waste water were industrially discharged out of 36.8 billion tons. 436 of the 532 rivers are polluted. The impact on the environment is a decreased standard of living. NEPAC reported that air pollution was slightly reduced in 4% of the cities in 1988, increased in 4%, and stable in the remaining cities. Water quality improved through the lowering of industrial waste water discharges, but 72% of river segments are still above the standards. Each major river system is discussed. Noise increased, and industrial solid wastes increased. Forest reserve is 9.141 billion cubic meters; the man-made forest has increased. The loss of grasslands is .13 million hectares/year. Cultivated land is 95.72 million hectares, but 100,000 hectares/year are damaged by natural disasters and 6 million are polluted by industrial wastes. 606 nature preserves have been established. In 1989, a complete legal system of environmental protection was established and investment increased.     

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.     

Relating briefly the natural resources and the population problems of China]

Problems in population, manifested primarily as either "over" or "under" population, are ultimately related to the development of natural resources. Land is the most basic of natural resources. China's land mass is largely mountainous, with 56% of its more than 2000 counties, 1/3 of its population, 40% of its cultivated land and a majority of its forests, situated in mountainous regions. The quality and the distribution of the various kinds of land are complex and uneven. Although China is rich in forests, grazing, and arable land compared to the rest of the world, its 1 billion population makes the land a limited resource. The limitations of the land are also seen in soil erosion, soil that is increasingly turning into sand, and deforestation. Water resources are not considered scarce, yet compared to the rest of the world, it is limited. Its distribution is very uneven, with more water in the east and west, and less in the north and south. In the southwest mountainous border regions, for instance, water is abundant, but the population and arable land there is such that the demand for water is low. Moreover, droughts and heavy precipitation make the annual water supply unpredicatable. The demand for water becomes increasingly greater as agricultural production develops further, the population increases and as the cities continue to expand. living matter as a resource includes all the animal and plant life that is necessary for livelihood, but only forests and grasslands are discussed here. China's forests, if their use is not abused, can serve as a continuous supply for manufactured products. But its distribution is uneven and sparse. Population control will be ineffective if the forests are not replenished and developed. Grasslands are the primary source for animal products. The natural grasslands, found mainly in the north and west, are not as productive as that of other nations due to the nature of China's topography, the vagaries of climate, and deterioration. Energy, the source for fuel, includes such natural resources as coal, petroleum, natural gas, hydraulic, and solar power. China is among the world's richest in energy resources, yet the supply is sometimes insufficient when spread among 1 billion people.     

中国未来发展面临的淡水资源问题及对策

中国的淡水资源总量处于世界较低水平 ,人均占有量只有世界平均水平的 1/4。现阶段 ,淡水资源已经成为影响中国经济和社会发展的因素。如果不尽快采取适当措施的话 ,下世纪淡水资源将成为制约中国经济和社会发展的重要因素。因此中国的淡水资源的利用必须按照可持续发展战略的要求 ,提出适应本国经济发展和人口增长的对策     

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.     

ZPG goals

1. Zero Population Growth (ZPG) believes that the present population of the U.S. exceeds the optimum level for the continued well-being of its citizens. ZPG therefore advocates the achievement, by voluntary means, of an end to U.S. population growth by 1990, and a reduction in U.S. population size thereafter. Among the conditions necessary to achieve this goal, ZPG stresses: freedom of access for every person to all means of voluntary birth control; a major research effort to develop safer and more effective means of birth control; complete equality of opportunity for all women and men; and removal of all legal and societal pronatalist pressures. The population size should stabilize at a substantially reduced level which will maximize diversity, freedom of choice, and the quality of life for all. 2. ZPG believes that land is a resource too important to human survival to be subjected to misuse. Ecological land use planning is essential in determining the appropriate patterns of distribution of people on the land, and of migration between states and regions. Thoughtful land use planning at all levels of government is necessary to assure the long-range stewardship of the land and well-being of mankind. 3. ZPG believes that human activities are causing the rapid depletion of the world's available stock of mineral resources. Simultaneously those activities are resulting in increased pollution of land, air, and water resources. ZPG therefore recommends 1) reduction in the rate of growth and eventual stabilization of U.S. consumption of nonrenewable resources; and 2) rapid stabilization of total national energy consumption at least until environmentally sound sources are developed. ZPG recognizes that none of its goals can be justified unless concurrently with their achievement adequate levels of income, health care, and educational opportunity are assured to all persons.     

Population and water resources: a delicate balance

Various avenues exist to minimize the effects of the current water crisis in some regions of the world and the more widespread problems that will threaten the world in the future. Active management of existing water resources and a reduction in population growth in water-scarce areas are needed to minimize the effects of the water crisis. National boundaries do not effect water systems. Cooperation and commitment of local, national, and international governments, institutions, and other organizations are needed to manage water systems. Development in each country must entail conscientious and effective balancing of unavoidable manipulations of the land and the unavoidable environmental impacts of those manipulations. The conditions of environmental sustainability must include protection of land productivity, ground water potability, and biodiversity. Humans must deal with these factors either by adopting methods to protect natural systems or by correcting existing damage and reducing future problems. They need to understand the demographic forces in each country so they can balance society's rising needs for clean water with the finite amount of water available. Factors affecting future needs at all levels include rapid rural-urban migration, high fertility, and changing patterns of international population movement. Given an increased awareness of global water systems, demographic trends, and active management of resources, the fragile balance between population and water can be maintained.     

Apocalypse when? Population growth and food supply in South Asia

Food demands for staple grains are expected to almost double over the next 25 years in South Asia, due to population growth and increased standards of living. Trends in the mid-1990s suggest that neither pessimism nor optimism prevails in the region. There is wide diversity among and within countries. Trends suggest that population densities are already the highest in the world, and the amount of arable land is declining. Urban growth has moved onto farm land and farmers have been pushed onto more marginal lands or have become landless. Land intensification has produced mixed results. Cereal production per capita has increased since the 1950s in India, with about 75% of the region's population, but Pakistan's increases were not sustained into the 1980s. Average daily caloric intake per person in the region of 2214 is below the level in Sub-Saharan Africa. In Bangladesh, levels are particularly worrisome at 2037. The environmental impact has not been easily quantified, but experts have suggested that pressure on farm land has contributed to loss of soil fertility and water resource loss. Further intensification of farming is feasible, but difficult and more expensive than in the past. Regardless of production problems and solutions, there is also the very real problem of poor food distribution and lack of purchasing power. Farm management skills must be utilized, if environmental degradation is to be avoided. There is the added unknown of what climate changes will occur and how agricultural production will be affected. The policy implications are that increased food production must be made a political priority. Policies must support agricultural research into improved technologies and support distribution of technological advances to a wider number of farmers. Rural infrastructures such as roads, market outlets, and credit agencies must be established. Policies must be removed that disadvantage farmers, such as inappropriate subsidies for irrigation water, inadequate tenure agreements, and price setting. Slowing population growth provides time to adjust to expanding production and saving the environment.     

人口老龄化的区域经济效应分析——基于新古典经济增长模型

人口老龄化与区域经济发展之间有着必然的内在关联性。因为生产和消费是区域经济发展中的重要环节,而人口老龄化对生产和消费均有影响,也就必然会影响区域经济的发展。因此,本文首先在梳理国内外相关研究的基础上提出人口老龄化对区域经济发展的双重效应——正效应和负效应;然后以新古典经济增长模型为基础,尝试引入人口老龄化因素从而对该模型进行扩展,分析得到的结论是:①进一步验证了人口老龄化对区域经济发展的双重效应的存在;②不同的区域,人口老龄化程度不同,人口再生产所处于的发展阶段不同,人口老龄化对区域经济发展的经济影响程度,即其正效应和负效应之和也就不尽相同,但存在的一个基本规律是,人口老龄化程度越高,其负效应就越大,其对区域经济发展的减速效应也就越明显。