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Ｉ.ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｐｏｐｕｌａｔｉｏｎｏｆｔｈｅＴｉｂｅｔＡｕｔｏｎｏｍｏｕｓＲｅｇｉｏｎｗｈｉｃｈｉｓｔｈｉｎｌｙｓｃａｔｔｅｒｅｄ,ｉｓａｌｍｏｓｔｅｎｔｉｒｅｌｙＴｉｂｅｔａｎ.Ｐｒｉｏｒｔｏｔｈｅｐｅａｃｅｆｕｌｌｉｂｅｒａｔｉｏｎｉｎ1951,Ｔｉｂｅｔａｎｓｕｓｅｄｔｏｂｅｒｕｌｅｄｂｙｔｈｅｌａｍａｉｓｔｓａｎｄａｒｉｓｔｏｃｒａｔｓｕｎｄｅｒｆｅｕｄａｌｓｅｒｆｓｙｓｔｅｍ.Ｔｈｅｕｎｉｑｕｅｈｉｇｈａｎｄｃｏｌｄｃｌｉｍａｔｅ,ｖａｒｉｅｄａｎｄｃｈａｎｇｅａｂｌｅｔｏｐ… 相似文献
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对腾格里沙漠东南缘不同的生境条件（包括始建于1964年的人工植被区和天然植被区）下油蒿（Artemisia ordosica）种群调查取样,按照植株的体积大小分为7个龄级（Ⅰ,0~2 cm3;Ⅱ,2~5 cm3;Ⅲ,5~10 cm3;Ⅳ,10~15 cm3;Ⅴ,15~20 cm3;Ⅵ,20~30 cm3;Ⅶ,>30 cm3）,分析了种群的组成、静态生命表和存活曲线。结果表明：人工植被区油蒿种群的总体规模大于天然植被区,幼龄个体占有很高的比例;天然植被区油蒿的死亡率低于人工植被区,天然植被区Ⅰ和Ⅱ龄级油蒿种群的死亡率最高,人工植被区Ⅴ~Ⅶ龄级的油蒿种群死亡率最高;天然植被区油蒿种群的稳定性维持主要通过幼苗的更新,而人工植被区可通过幼苗的自我更新和大龄植株的自疏作用;Ⅴ龄级的油蒿个体是种群中的生存质量最佳的个体;两种生境下油蒿种群均符合Deevey Ⅱ型存活曲线。 相似文献
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人口死亡率是人口转型关键因素之一,而人口转型又关系着地区社会经济发展质量。以2000—2015年粗死亡率数据为基础,通过变异系数、趋势分析和空间自相关分析中国人口死亡率空间格局差异及演变态势,并结合偏最小二乘回归定量分析人口死亡率影响因素。结果发现：（1）中国人口死亡率大致呈西北、东北和东南低,中部及西南高态势,且各时段人口死亡率降低省份高于增长省份;（2）中国各省死亡率变异系数差异悬殊,且在空间趋势中东西方向呈现两端低中间高、南北方向由两端低中间高向北低南高转变;（3）人口死亡率全局空间集聚程度不断减弱,区域差异缩小,且局部空间上以高-高和低-低聚集为主;（4）人口老龄化是人口死亡率提升的主要推动因子,其次分别为工业废水排放总量、突发环境事件次数和气候条件等。人均生产总值对人口死亡率起主要抑制作用,其次分别为每千人口床位数、每十万人口大学平均在校生数、人均用水量和空气质量。农作物受灾面积合计对人口死亡率在不同年份作用力不一致。 相似文献
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本文从人口城镇化的基本原理开始,讨论了建国以来我国省域城镇人口变化的基本特点,并进行了人口城镇化的相关因素分析。 相似文献
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Mukherji D Sita K 《Population geography : a journal of the Association of Population Geographers of India》1982,4(1-2):76-80
In view of the importance of migration in Maharashtra state. India an attempt is made to identify the areas of out-migration, and to assess the probable causes for it. The analysis is confined to the decade 1961-1971 and based on secondary data, with the taluka as the unit of analysis. The total number of births and deaths in each taluka for the period of study was complied and enabled the natural increase of population to be computed. A comparison of this with the actual increase as indicated by the census made it possible to identify the areas of out-migration. The study revealed that the out-migration talukas were located in 3 areas and that the relative significance of out-migration varied. The analysis indicated that the causes of out-migration were probably unfavorable relief efforts, susceptibility to drought, closure of household industries, and the 'pull' effect of metropolitan centers like Bombay. 相似文献
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Heleniak T 《Post-Soviet geography》1995,36(10):644-648
"Since the Russian economy recently has shown sings of stabilization, there now is evidence that demographic trends are beginning to improve somewhat. Although the population declined by 164,200, to 148.1 million at the beginning of 1996, the release of new statistical compendia by the Russian statistical agency (Goskomstat Rosii) in 1995 and early 1996 makes it possible to identify several positive trends.... Life expectancy increased for the first time since 1985. The infant mortality rate declined for the second year in a row. The crude death rate declined for the first time in a decade. The birth rate remained at about the same level for the third consecutive year. The rate of natural increase (births minus deaths), although still negative, recorded a moderate increase." 相似文献
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本文根据全国历来四次人口普查资料，对我国塔吉克族人口形热进行了简要的论述。文中阐述了塔吉克族人口规模的发展、变化以及人口再生产类型，并简述了相关的社会、经济、文化等方面的问题。 相似文献
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Rogge JR 《The Journal of geography》1982,81(5):164-174
There is every indication that Africa's population growth will remain well above the world average for the remainder of this decade and probably for the rest of this century. With the exception of the island states and parts of North Africa, fertility levels show little indication of change. This is in part a reflection of little desire for small families, as well as a consequence of limited or even restricted family planning services. Great diversity in attitudes regarding population policy prevails among African governments, ranging from extreme pronatal to committed antinatal. Even with antinatal policies, however, many African states have yet to attain any significant success in depressing their rates of growth. To date, Mauritius can be cited as the only state to have almost achieved the transition from high to low fertility. The consequence of these continuing trends is that Africa will see further increases in its youth dependency ratio. Pressures on infrastructural services will therefore increase, and the problems of generating employment will intensify. While demographic factors are by no means the only ones creating economic stress on the continent, they clearly are contributory. Unlike Asia or parts of Latin America, Africa's problem is less a matter of too many people but rather 1 of excessive growth in too short a time frame. A realistic and effective long-term population policy, therefore, is an immediate need. Several countries including Nigeria (with a pouplation of over 80 million) are experiencing a crude birth rate of 50 or more/1,000. At least 4 countries, including Kenya, are currently doubling their population in 20 years or less. With these current population trends, a demographic transition to low vital rates must assume passage through an even higher growth phase than is currently being experienced because the fall in birth rates tends to occur much later than the fall in death rates. Government population policies and the status of family planning activities are illustrated according to natal sentiments and attitudes. Trends in national vital rates and of population structures in Africa are illustrated. 相似文献
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Singh RN Chaturvedi RP 《Population geography : a journal of the Association of Population Geographers of India》1984,6(1-2):53-65
This paper analyzes the growth of population and its various characteristics in the Bundelkhand region of India. Bundelkhand region--a distinct histocultural and geographic unit--is a transitional zone between the 2 major physiographic divisions of India: the Gangetic plain and Peninsular India. The region is a less developed part of India where people are living in low social status with poor economic conditions; agriculture is the mainstay of the people, but the region suffers from the inadequacy and inefficiencies of irrigation facilities. The history of population growth of the region during the last 80 years has followed a multivariate course; besides the interplay of birth and death, in-migration contributes considerably to the population growth. The 1st phase (1901-1921) is that of progressive decline causing a very slow population growth--population decrease was mainly due to the influenza epidemic of 1918-19. The 2nd phase (1921-1951) was a period of moderate population growth due to the national political movements and disturbances together with some natural disasters. The 3rd phase (1951-1981) is marked by a rapid population growth mainly due to the decline in the death rate. Over the last 80 years, the total population of the Bundelkhand region increased from 3.45 million to 8.03 million--a net increase of 132.58%. However, this change is not high when compared to the national average of 176.11%. The total population of the region in 1981 (8,037,206 persons) is expected to reach 8,874,000 persons in 1991, and 9,797,000 persons in 2001. This will undoubtedly put enormous pressure on the resources of the region slowing down the pace of economic progress. 相似文献
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吉林省人口老龄化时空分异特征及成因 总被引：1，自引：0，他引：1
本文基于地理信息软件ArcGIS 10.1,选取老年人口系数为人口老龄化指标,运用人口重心模型、空间自相关和半变异函数等分析方法,对吉林省第四次、第五次、第六次人口普查数据进行分析,探讨1990-2010年吉林省人口老龄化时空分异特征,并采用多元线性回归方法解释其形成原因。研究结果表明：①吉林省各县市人口老龄化差异明显,进程加快,重心由西北向东南方向移动,但移动速度减缓;②吉林省人口老龄化存在正的空间自相关性,在空间的集聚呈现先弱后强的变化趋势;③人口老龄化高—高区向东部集聚,低—低区向西部集聚的趋势比较明显;④总体上吉林省人口老龄化空间的结构化分异较为明显,随机性因子引起的空间异质性程度较弱,人口老龄化的空间差异主要体现在东—西方向上;⑤出生率始终是影响吉林省人口老龄化的主要因素,迁出率对人口老龄化发展起关键作用,人均GDP年对人口老龄化呈负相关,城市化率对人口老龄化的推动作用愈发显著。 相似文献
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根据1951-2001年奥地利人口调查统计数据,分析了近50年来奥地利人口变化的时空间规律,以及人口变化中的增长区和下降区的区域配置等特征,并建立人口变化模式。研究表明：20世纪后半叶奥地利经历了其他欧盟国所表现出的城市化、城市郊区化和人口老龄化的各个过程。特别是城市老龄化表现更为突出,据预测推算,到2035年奥地利将会有1/3的人口超过60岁。在分析过程中,不仅应用了行政区划的区域方法,而且也依据土地利用的经济性质,在“土地经济生产小区”的基底上,对人口的变化规律进行了更为深入的透视。研究结果显示：奥地利西部阿尔卑斯山地中的城市区域人口增长幅度最大。沿着捷克和斯洛伐克边界伸展的北部和东北部区域是最严重的人口缺失地区。而奥地利阿尔卑斯山地东部的一些早期产业都市及其郊区,乃至更远一些的南部和东南部的老工业区域,目前由于普遍存在着经济的困境,也直接导致了这些地区人口的下降。但奥地利未来的总人口趋势将持续稳定。 相似文献
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Sagar P 《Population geography : a journal of the Association of Population Geographers of India》1991,13(1-2):63-84
The author investigates literacy differentials between tribal and non-tribal populations in India, using 1981 census data. "Spatially, the index is high in tradition gripped and economically backward areas of Western Rajasthan, of central highlands and of Western Arunachal Pradesh. It is low in [the] Christian tribal belt of [the] northeast; the early exposed areas of [the] southern peninsula, parts of Gujarat, Maharashtra and Karnataka, and numerically insignificant areas of northern Rajasthan and Western Himalayas." 相似文献
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Gosal GS 《Population geography : a journal of the Association of Population Geographers of India》1982,4(1-2):33-53
Apart from a generalized discussion on the trends of population growth in India during the post-Independence decades and its socio economic implications, this paper examinies in some detail the spatal patterns of population change in India during 1971-1981. The discussion is mainly based on what has emerged on 3 maps depicting percentage change in general and rural and urban population change in India during this decade. While areas of rapid growth of population continue to be associated with net in-migration resulting from: 1) the development of manufacturing industries, mining, trade, and miscellaneous services, all leading to acceleration in the process of urbanization, 2) the development of irrigation and reclamation of land bringing about increased intensity and extension in farming, and 3) infiltration from neighboring countries, particularly from Bangladesh. The areas of relatively low growth are mostly those which have suffered net out-migration induced by pressure of population and paucity of resources or a desire to seek better avenues of employment elsewhere. Superimposed on this is the new trend of declining rate of natural increase, such as in Kerala and Tamil Nadu, which has played its own role in bringing down the overall growth rate. Likewise there are areas, such as in Uttar Pradesh, Bihar, and Rajasthan, where recent breakthroughs in the mortality rate, with the birth rate staying at a high level, has stepped up the process of demographic dynamism. A comparison of the spatial patterns of 1971-1981 with those witnessed in precious decades brings out important chnges in these patterns which are occurring as a result of the various areas of the country getting into different phases of the second stage of the "demographic transition." With a view to bringing the benefits of socioeconomic progress to the door steps of all sections of the society in all parts of the country, it is necessary to bring about a substantial decline in the birth rate without any further loss of time. 相似文献
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中国人口老龄化空间格局演变及其驱动因素 总被引：1，自引：1，他引：1
基于第五、六次人口普查数据,采用ESDA和空间计量模型分析中国地级单元人口老龄化的空间格局演变特征及驱动因素。结果表明：① 胡焕庸线是中国人口老龄化呈东高西低的显著分割线,随着老龄化不断加深,最初自西向东阶梯上升的空间格局逐渐模糊;② 各地级单元间人口老龄化存在较强的空间正相关性,呈现出高-高和低-低相似值集聚的空间分布特征。其中高-高集聚区主要分布在长三角、成渝、山东半岛、辽中南等地区,低-低集聚区主要分布在西北地区、西南部分地区、东北地区西部和珠三角部分地区,10 a间这种正向的空间集聚特征减弱;③ 中国人口老龄化空间格局演变是由人口因素和社会经济因素共同作用决定的,人口因素是直接原因,根本原因是地区社会经济发展的不平衡所致。对此,分别从人口和社会经济角度提出应对人口老龄化对策建议。 相似文献
16.
桂西北喀斯特山区人口分布特征及其与自然因素的关系 总被引：1，自引：0，他引：1
选择第六次全国人口普查的最小行政单位——乡（镇）为基本单元,利用Lorenz曲线和空间相关分析方法分析桂西北喀斯特山区乡（镇）级尺度下的人口空间分布特征,运用地理探测器方法探测自然因素单独和叠加作用后对区域人口空间分布的影响强度。结果表明： 乡（镇）级研究尺度下的人口空间分布具有不均衡性特征,呈现一般显著正相关和一定的聚集性; 各自然因素空间分布对人口分布的影响呈现显著差异,研究区西北和中南部没有喀斯特分布的乡镇,人口密度随有利于人类居住因素的增加而增加,但平均人口密度仅79人/km 2。东部和南部有喀斯特分布的乡镇,人口密度与自然因素空间分布并非简单的增减关系,其随喀斯特分布面积的变化呈现起伏波动。 地理探测器的因子探测结果显示对人口空间分布的影响强度最大的为海拔高度,交互探测结果显示,任意两个自然因素叠加交互作用后的影响强度呈现非线性增强和双因子增强。可见,桂西北喀斯特山区与其他地区类似,海拔高度是影响人口空间分布的最主要因素之一,但喀斯特山区的河网密度及特有的地质地貌等因素对其人口的空间分布具有较强的催化作用,与其他因素叠加交互作用可进一步加强对人口分布的影响。 相似文献
17.
深入探究半干旱区景观格局变化规律,明确其生态风险时空演变特征与影响因素,对优化半干旱区景观格局、防范和治理生态风险、促进区域可持续高质量发展具有重要意义。以宁夏回族自治区盐池县为例,基于2000—2020年土地利用数据,通过景观格局指数构建生态风险模型,结合地统计分析和地理探测器模型,对其景观格局变化及生态风险时空演变与影响因素进行综合研究。结果表明：（1） 2000—2020年盐池县耕地和未利用地面积下降,其余地类均呈增加趋势,其中建设用地扩张速度最快,年均增长率为6.90%。（2） 2000—2020年盐池县景观斑块数、斑块密度、景观形状指数和香浓多样性指数上升,最大斑块指数和蔓延度指数下降,表明景观格局呈破碎化、复杂化和分散化的发展态势。（3） 2000—2020年盐池县生态风险指数由0.1465下降至0.1312,其中高、较高和中等风险区面积占比分别下降5.25%、24.21%和5.44%,而低和较低风险区面积占比分别增加14.11%和20.79%,空间上呈现出北高南低的分布格局。（4） 随着社会需求的日益增长和人类活动的加剧,自然因素对生态风险空间分异格局的影响逐渐弱化,而社会经济因素作用不断增强。 相似文献
18.
1990—2015年中国县市尺度人口收缩的演变特征及影响因素 总被引：1，自引：0，他引：1
近年来,区域人口收缩问题在全球范围内引起了广泛关注,并且在中国也日益明显。利用1990年、2000年和2010年人口普查数据以及2015年1%人口抽样调查数据,本文在县市尺度上分析了1990—2000年、2000—2010年和2010—2015年三个时期人口收缩区的空间特征及演化趋势,并定量探讨了其形成与演变的影响因素,主要发现如下：① 人口收缩现象在县市尺度非常明显,三个时期人口收缩区占比均超过20%;② 2000—2010年人口收缩区以大面积扩张为主要特征,东北地区、川黔渝地区、长江中游地区最为明显,而东部地区则主要集中在江苏北部和福建西部等局部范围;③ 2010—2015年人口收缩转缓慢增长成为主要特征,仅东北地区、河南等人口收缩区仍有所扩张;④ 人均GDP和非农就业占比等经济发展水平因素对人口收缩区的形成影响显著,而经济发展速度因素则与人口收缩的演变密切相关;⑤ 除经济因素外,人口自然增长因素对人口收缩区形成及演变的影响均非常显著,且其作用呈增强趋势。 相似文献
19.
长江上游社会经济因子对侵蚀产沙的影响 总被引：1，自引：0，他引：1
In recent years,the role of human activities in changing sediment yield has become more apparent for the construction of hydraulic engineering and water conservation projec-tions in the Upper Yangtze River,but it has not been evaluated at the macro scale.Taking Sichuan Province and Chongqing City as an example,this paper studies the relationship between socio-economic factors and sediment yield in the Upper Yangtze River based on section data in 1989 and 2007.The results show that sediment yield is significantly correlated with population density and cultivated area,in which the former appears to be more closely related to sediment yield.Moreover,in the relation of sediment yield vs.population density,a critical value of population density exists,below which the sediment yield increases with the increase of population density and over which the sediment yield increases with the decrease of population density.The phenomenon essentially reflects the influence of natural factors,such as topography,precipitation and soil property,and some human activities on sediment yield.The region with a higher population density than critical value is located in the east of the study area and is characterized by plains,hills and low mountains,whereas the opposite is located in the west and characterized by middle and high mountains.In the eastern region,more people live on the lands with a low slope where regional soil erosion is slight;therefore,sediment yield is negatively related with population density.In contrast,in the western region,the population tends to aggregate in the areas with abundant soil and water resources which usually lead to a higher intensity of natural erosion,and in turn,high-intensity agricultural practices in these areas may further strengthen local soil erosion.It is also found that popu-lation tends to move from the areas with bad environment and high sediment yield to the areas with more comfortable environment and less sediment yield.The natural factors have greater influence on sediment yield of western region than that of eastern region.Generally,the natural factors play a dominant role on sediment yield in the Upper Yangtze River. 相似文献
20.
Ramachandran J 《Population geography : a journal of the Association of Population Geographers of India》1984,6(1-2):39-52
The authors examine the relationship between population growth and agricultural change using a village-level study of the Warli tribal community in Maharashtra, India. "This paper tries to highlight the relationship that exists between the two factors and the relative changes in the structural character of the two factors. It also focuses on the complications brought about by the juxtaposition of a market economy of the nontribals on the subsistence peasant agriculture of the Warli tribals. Methodology is empirical. Suitable statistical aids have been used on available census material [for the years 1901-1971], substantiated with fieldwork." 相似文献