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941.
Population movement is an important phenomenon in China in recent years. Its mechanism is: (1) thrust of more people and less land in the eastern region of China; (2) attraction of dual economy in the western region of China; (3) national policy on preferential wages and grains for the western region. Population movement has an important effect on the change of regional division pattern in China: by the medium of the moving people, there forms another regional division pattern, i.e. rural industry system based on rural town industry; (2) there forms another profit mechanism compensated from the western region to the eastern region. It not only wins more profit in the eastern region, but also changes dual economy in the western region. Therefore, We should make choice of a comprehensible and encouraging attitude on population movement; a special government organization for general survey of the moving people should be set up at once.  相似文献   
942.
Since 1949, great changes have taken place in the amount and distribution of China's urban population. From the analysis on the change in total urban population, it can be learnt that urbanization progress can be controlled mainly by social-economic development and government policy through influencing the migratory growth of urban population and the number of organic cities. In the period 1949-1990, the states of megalopolises had gone up; medium-sized cities had decreased. It is estimated that the total urban population of China will still increase at a rapid speed in the coming 10 years; there will not be great changes in grade system of urban scale; and urban population may shows a tendency to move to coastal area.  相似文献   
943.
张伟  裴敏洁 《热带地理》2022,42(5):762-772
从城市收缩的维度类别、维度数量、时序演化3个方面入手,提出了一套新的多维度分析框架,并将其应用于中国城市收缩的时空演变特征分析。结果表明:1)在1995—2000、2000—2005、2005—2010和2010—2015这4个时期中,人口收缩城市占中国城市总量的比例分别为9.55%、20.34%、15.34%和19.72%;经济收缩城市占比分别为5.32%、4.85%、0.47%和8.29%;空间收缩城市占比分别为7.04%、3.44%、3.76%和1.72%。2)相对于欧美发达国家,中国的城市收缩现象并不是很严重,大部分人口收缩城市的收缩率均低于3%。3)中国的城市收缩现象存在3个悖论:93.03%的人口收缩城市的建成区面积在扩张,92.37%的人口收缩城市的国内生产总值(GDP)在增长,94.57%的经济收缩城市的建成区面积在扩张。这与中国的要素依赖型经济增长模式和地方政府的土地融资模式等存在较强的关系。文章所构建框架具有较好的灵活性和较强的适应性,有助于增强收缩城市研究的可比性。此外,该框架在推动城市多维度收缩的类型学研究,分析城市收缩的时序演化规律等方面也具有较大的潜力。  相似文献   
944.
城镇化推进过程中,人口流入经济发达的大中城市,而高房价使住房租赁需求日益增加。人口、经济与住房租赁市场相互影响,三系统的协调发展是城市可持续发展的必然要求。在构建人口-经济-住房租赁市场系统评价指标体系的基础上,采用耦合协调及空间误差模型,探讨2018—2019年中国35个大中城市人口-经济-住房租赁市场三系统的耦合协调水平及其影响因素。研究发现:1)人口、经济和住房租赁市场作为3个社会系统,彼此相互影响。在城市可持续发展视角下,三系统之间的协调发展应是人口合理流动、经济运行良好与住房租赁市场平稳运行,三系统共赢共荣。2)35个大中城市人口与经济综合水平整体有所上升,但住房租赁市场综合水平稍有下降。3)35个大中城市人口-经济-住房租赁市场系统的耦合协调度有所上升,但各城市间耦合协调水平差异变大,其中划入住房租赁试点城市的耦合协调度相对较高。同时,东部城市耦合协调度普遍较高,其中上海市和北京市已达到良好协调水平,其他城市基本为初级协调水平;中部和东北部城市大多为勉强协调水平;西部城市大多处于濒临失调水平。4)经济结构、人口规模、房地产市场发展水平与教育资源是提高人口-经济-住房租赁市场系统协调水平的重要因素。  相似文献   
945.
The reintroduction of rare and endangered species is one of the most important approaches to conservation and ecosystem restoration, but it has still proven to be an adventurous undertaking and most reintroduction programmes fail, so successful demonstrations are needed. Père David’s deer (Elaphurus davidianus, Milu in Chinese) could be considered one of conservation’s great success stories, as this species’ path on the road to extinction has been reversed by a combination of ex-situ conservation and successful re-introduction in China. The species had been consigned to an imperial hunting ground when the last Chinese herds were exterminated during the fall of the Qing Dynasty (1644-1912). Fortunately, a few of the last remaining individuals were sent to European zoos. From these animals, a herd was bred on the 14th Duke of Bedford’s estate, Woburn Abbey, and between 1985 and 1987, and 38 Milu were donated back to China for re-introduction in Beijing Milu Park (BMP), the former imperial hunting ground. An additional 39 deer were released at Dafeng National Nature Reserve (DFNNR), Jiangsu Province in 1986. In both of these safe and protected locations, the Milu thrived allowing for over 700 Milu to be sent to a further 82 sites throughout the species’ original Chinese range over the last 36 years. As a result, the Milu population totaled 9136 by 2021, with 2855 individuals now living back in the wild; while another 5681 individuals inhabit the DFNNR, and 186 reside in BMP. Wild Milu, however, still face significant conservation challenges. The population lacks genetic diversity, leading to severe inbreeding depression and carrying multiple risks, such as high miscarriage rates, a reduced lifespan, and susceptibility to disease. Environmental constraints such as pollution and habitat fragmentation further result in small, fragmented wild populations. Moreover, the species currently lacks a national level conservation master plan, the associated coordinated monitoring platforms, and breeding plans for China’s captive populations. Finally, there is now a lack of international cooperation in the conservation of this species. We therefore call for both a national-level conservation master plan in China and international cooperation to develop a shared database and germplasm databank covering Milu across all countries with ex-situ populations, as crucial steps for securing the long-term conservation of Milu and preventing it from ever becoming “extinct in the wild” again.  相似文献   
946.
地震发生时刻、震级、极震区烈度评估、烈度衰减关系模型、人员伤亡评估模型、房屋震害矩阵等是影响地震灾害损失计算的主要因素,各因素存在不确定性,导致评估结果与实际结果存在一定差距。文中对2019年6月19日四川长宁6.0级地震灾害损失快速评估精准性进行分析,探讨极震区烈度评估、地震影响场、烈度衰减关系模型、人员伤亡评估模型、房屋震害矩阵对评估结果的影响及与真实结果存在的偏差,结果表明,提高地震影响场评估、人口、房屋建筑等数据空间分布精准性,是提高地震灾害损失快速评估系统精准性的基础和前提。  相似文献   
947.
王军  李真  周资行  王平  焦健  李毅 《中国沙漠》2014,34(5):1268-1276
对兰州市永登县半荒漠植被区天然分布的红砂(Reaumurta soongorica)种群实地调查取样,利用红砂植株地径大小与相应年轮年龄的关系,得出回归方程,求出各地径对应年龄,编制静态生命表、分析动态指数、存活曲线、生存分析曲线。结果表明:各生境红砂种群均表现出新苗和幼株丰富,占种群株数的比例大;所有样地存活曲线均接近于Deevev-Ⅲ型(凹型);静态生命表显示,生境异质性,特别是水分差异,致使红砂种群表现出2种不同的环境适应策略;各生境种群动态指数均基本为正值,充分说明样地内的红砂种群基本处于发育状态,整体上是稳定增长的。  相似文献   
948.
The relationship between population distribution and resources, environment and social-economic development has a significant influence on the human development. This paper set up a set of index system and model methods for the assessment of the coordination between population and resources, environment and social-economic development, and it quantitatively evaluated this coordination at the provincial scale in 2000 and 2010 respectively. Based on this set of index system, the suitability degree and the spatial-temporal pattern of population distribution at the provincial scale were carefully characterized. The restriction of population distribution at the provincial scale was graded and classified, and the coordinated development strategy of population, resources, environment and social economy was finally put forward. The results showed that:(1) The environmental suitability of population distribution at the provincial scale was generally high in China, which tended to be stable from 2000 to 2010.(2) The restriction of water and land resources at the provincial scale was generally strong in China, but it tended to be weak from 2000 to 2010.(3) The coordination degree between the social-economic development and population distribution at the provincial scale was mostly at a middle level, which was in the positive upward path from 2000 to 2010.(4) The suitability of population distribution at the provincial scale was mostly at a middle level, all of which was rising from 2000 to 2010.(5) The coordination degree between population distribution and resources, environment and social-economic development at the provincial scale was divided into four grades, including basic coordination, relative coordination, awaited coordination and urgent-needed coordination.(6) The basic ways to promote the coordinated development of population, resources and environment in different regions in China can be summarized as: implementing the strategy of population agglomeration and evacuation, guiding the orderly flow of population, optimizing the spatial distribution of population and drawing up the spatial planning of population development.  相似文献   
949.
The relationship between population distribution and resources, environment and social-economic development has a significant influence on the human development. This paper set up a set of index system and model methods for the assessment of the coordination between population and resources, environment and social-economic development, and it quantitatively evaluated this coordination at the provincial scale in 2000 and 2010 respectively Based on this set of index system, the suitability degree and the spatial-temporal pattern of population distribution at the provincial scale were carefully characterized. The restriction of population distribution at the provincial scale was graded and classified, and the coordinated development strategy of population, resources, environment and social economy was finally put forward. The results showed that: (1) The environmental suitability of population distribu- tion at the provincial scale was generally high in China, which tended to be stable from 2000 to 2010. (2) The restriction of water and land resources at the provincial scale was generally strong in China, but it tended to be weak from 2000 to 2010. (3) The coordination degree between the social-economic development and population distribution at the provincial scale was mostly at a middle level, which was in the positive upward path from 2000 to 2010. (4) The suitability of population distribution at the provincial scale was mostly at a middle level, all of which was rising from 2000 to 2010. (5) The coordination degree between population dis- tribution and resources, environment and social-economic development at the provincial scale was divided into four grades, including basic coordination, relative coordination, awaited coordination and urgent-needed coordination. (6) The basic ways to promote the coordinated development of population, resources and environment in different regions in China can be summarized as: implementing the strategy of population agglomeration and evacuation, guiding the orderly flow of population, optimizing the spatial distribution of popu- lation and drawing up the spatial planning of population development.  相似文献   
950.
Jurisdictional domains are legal divisions of the Earth’s surface frequently used in classification and search systems for location-based queries. However, there are few compilations of jurisdictional domains that include their evolution. One of the causes is the complexity of their generation. As an advance in this area, this paper describes a process that facilitates the creation of knowledge bases containing the evolution of jurisdictional domains. As application example, this paper presents the creation of a jurisdictional knowledge base of Spain with its evolution between 1830 and 2011.  相似文献   
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