共查询到20条相似文献，搜索用时 15 毫秒
1.
基于第五次和第六次人口普查数据,研究了乡镇尺度上山东省人口老龄化的空间格局及其演变特征,并采用空间计量方法定量探讨了其影响因素。研究发现：① 山东省人口老龄化发展迅猛,但乡镇街道之间在老龄化水平、老年人口密度和增长速度等方面均存在非常显著的地域差异。② 按照不同的分析维度,山东省乡镇街道涵盖了丰富的人口老龄化地域类型,其中的2个类型形成了典型的空间分异格局。一类主要聚集在县级以上城市及其周边地域,总体上具有老年人口低占比、高密度、高绝对增长、低相对增长的特点;另一类是主要分布在胶东地区、黄河三角洲地区、沂蒙地区和鲁西地区等4个区域的一般乡镇,大体表现为高占比、低密度、低绝对增长、高相对增长特征。③ 空间滞后模型回归结果显示,老龄化动态演变过程的不确定性更强、影响因素更为复杂,基期老龄化基础对其影响效应不显著,经济增长速度有显著负向影响,但经济发展水平对老龄化静态格局的影响却不显著,使得乡镇尺度上老龄化空间格局的演变机制呈现出特殊性。 相似文献
2.
阿尔泰山中东部西伯利亚落叶松生长量及其对气候变化的响应研究 总被引：3，自引：0，他引：3
利用阿尔泰山中东部两个样点(AYS、SYK)的西伯利亚落叶松(Larix sibirica)树轮资料,采用新疆西伯利亚落叶松一元材积式获得1969-2011年材积生长量序列。利用相关分析和回归分析等方法对生长量数据和气象资料进行分析,研究气温要素与生长量的关系及树木生长对气温和降水变化的响应。结果表明:近50 a来,西伯利亚落叶松材积生长量表现出显著增加趋势,且与生长季气温有较好的相关性;与当年6月降水量呈负相关趋势,8月降水量呈正相关趋势;生长季平均气温在19~20.9℃时,西伯利亚落叶松生长量最大;SYK样点西伯利亚落叶松生长对气温变化的敏感性高,气温每升高1℃生长量增加0.936 mm3·棵-1;AYS样点西伯利亚落叶松生长对气温变化的敏感性较低,气温每升高1℃生长量增加0.661 mm3·棵-1。 相似文献
3.
Bo Huang Li Zhang Bo Wu 《International journal of geographical information science》2013,27(3):379-398
Understanding the complexity of urban expansion requires an analysis of the factors influencing the spatial and temporal processes of rural–urban land conversion. This study aims at building a statistical land conversion model to assist in understanding land use change patterns. Specifically, GIS coupled with a logistic regression model and exponential smoothing techniques is used for exploring the effects of various factors on land use change. These factors include population density, slope, proximity to roads, and surrounding land use, and their influence on land use change is studied for generating a predictive model. Methods to reduce spatial autocorrelation in a logistic regression framework are also discussed. Primarily, an optimal sampling scheme that can eliminate spatial autocorrelation while maintaining adequate samples to allow the model to achieve the comparable accuracy as the spatial autoregressive model is developed. Since many of the previous studies on modeling the spatial complexity of urban growth ignored temporal complexity, a modified exponential smoothing technique is employed to produce a smoothed model from a series of bi‐temporal models obtained from different time periods. The proposed model is validated using the multi‐temporal land use data in New Castle County, DE, USA. It is demonstrated that our approach provides an effective option for multi‐temporal land use change modeling and the modeling results help interpret the land use change patterns. 相似文献
4.
中国北方未来50年土地利用变化模拟 总被引：1，自引：0，他引：1
1 IntroductionLand use m odelling is a useful tool to analyze the land use cause, process and result, torecognize the im pact of land use system change on ecological environm ent,and to support theland use planning and policy (IIA SA ,1998;Costanza etal.,… 相似文献
5.
Modelling scenarios of land use change and their impacts in typical regions are helpful to investigate the mechanism between land use and ecological systems and process the land use allocation under the ecological security. A system dynamics (SD) model with the aim to modelling scenarios of land use change and assessing ecological impact in northern China in the next 50 years is developed here. The accuracy assessment with the historic data from 1990 to 2001 indicated the SD model is robust. After the different "what-if" scenarios controlled by GDP, population, market, and technology advancement were built, the different scenarios of land use change in northern China from 2000 to 2050 were simulated with their ecological impact assessed. The result suggested that such factors as GDP, population, market and technology have a strong relationship with land use structural change in northern China. It also indicated that such measures as strict controlling of population increase, importing some food to keep the supply-demand balance in the region, and improving agricultural technology will be the guarantee of regional sustainable development with fast economic growth and the obvious land use structural improvement at the same time. 相似文献
6.
Jae Hong Kim 《International journal of geographical information science》2013,27(9):1782-1803
This study examines how land-use change simulation outcomes can vary based on the way the simulation model is applied, attempting to support informed model choices and model applications. This is accomplished through a series of experiments using a hypothetical model that represents the basic logic of various cell-based dynamic land-use change modeling environments. In the experiments, consideration is given to the sensitivity of the simulation results with respect to the following four application specifications: (1) the spatial resolution, (2) the temporal resolution, (3) the probability distribution, and (4) the degree of the influence of stochastic factors, under multiple growth scenarios. The experiments show that all four factors, particularly the spatiotemporal resolution and the degree to which stochastic factors are involved, can generate substantial variation in the simulation model outcomes. It is also found that the magnitude of the variation can be affected by changes in regional growth rates and the level of fluctuation, which determine the demand for new development to be allocated over the simulation time horizon. 相似文献
7.
中国北方未来土地利用变化情景模拟 总被引：56，自引：5，他引：51
利用系统动力学 (SD) 的原理和方法,发展了区域土地利用情景变化SD模型。在不同系统状态下,模拟了中国北方13省未来50年不同社会经济情景下的区域土地利用结构变化,并初步评价了这些变化的可能生态影响。1990~2001年的模型结果表明该SD模型具有一定的可靠性,能在一定程度上为当前理解土地利用系统的复杂驱动行为,评估脆弱生态区土地系统变化的潜在生态效应提供帮助。2000~2050年的情景仿真结果表明,经济、人口、市场和技术等因素对中国北方13省未来土地利用变化的影响非常明显。 相似文献
8.
基于OMI卫星数据的城市对流层NO2变化趋势研究 总被引：1，自引：0，他引：1
利用OMNO2全球产品卫星遥感资料研究科技城市北京、交通城市黄骅港、旅游城市三亚、特区城市深圳和工业城市抚顺的NO2月平均变化情况。通过Beat软件和IDL联合编程对该产品进行处理,得到各城市对流层NO2垂直柱密度的月平均值;对各城市2004年10月至2007年10月的NO2月平均变化进行线性正弦模型模拟,得到月平均变化趋势和月增长率,并评价变化趋势的精度。结果显示,各城市在冬季NO2对流层垂直柱密度较大,夏季较小,季节性循环明显。北京、黄骅港、三亚、抚顺在这段时间NO2总体呈增加趋势,从大到小依次是:抚顺、北京、黄骅港和三亚,深圳呈减少趋势。根据趋势显著性判别准则,各城市的NO2月平均变化均显著。另外相对于2004年10月,月相对增长率从大到小依次是抚顺、三亚、黄骅港、北京、深圳,其中深圳的NO2呈现负增长。 相似文献
9.
中国出口导向型外资企业时空演化与出口增衰机制 总被引：1，自引：1，他引：0
利用2000-2013年中国海关贸易数据库出口数据研究分析中国出口导向型外资企业地理格局演变.研究发现,出口导向型外资企业在数量和出口贸易额呈现增长的趋势,出口产品以资本密集型、技术密集型产品为主,主要集中在京津冀、长三角、珠三角、山东半岛、辽中南地区,存在从沿海向中西部内陆地区、由核心城市向周边城市逐渐扩散的特征,外... 相似文献
10.
基于EOF和GWR模型的中原经济区经济增长的时空分析 总被引：2，自引：0，他引：2
结合中原经济区“三化”协调发展的国家战略,基于自然正交函数（EOF）分析中原经济区经济增长的时空特征,借助地理加权回归（GWR）揭示其驱动力。EOF第一模态分析表明：中原经济区经济增长的空间分布沿京广线的东西两侧反相分布,京广线以西增长快于京广线以东;时间系数表现出明显的年际特征,且东、西两部分有近10 年的循环周期。第二模态反映局部区域经济增长的年际异常,其呈西南、东北反相空间分布;时间系数年际波动明显。GWR分析发现：驱动力的作用在空间上存在差异。农民人均纯收入对中原经济区经济增长的影响最大,呈正相关关系。资源禀赋是第二大影响因素,也呈正相关关系。经济区位是第三大影响因素,其他因素依次是第二产业、城市化和农业机械总动力。影响中原经济区经济增长的因素有明显的经度地带性规律。因此,制定区域发展政策时,要考虑不同行政区的特殊性。 相似文献
11.
Modeling Spatial Processes of Urban Growth in African Cities: A Case Study of Nairobi City 总被引：1，自引：0，他引：1
《Urban geography》2013,34(2):259-272
Africa's urban population growth has been especially rapid, averaging about 5% per year over the past two decades. As a result, many urban areas have experienced dramatic growth that is seriously outstripping the capacity of most cities to provide adequate services for their residents. Although population growth and urbanization rates in Africa have slowed recently due to a number of factors including HIV/AIDS, urban growth is still expected to double by 2030, leading to dramatic sprawl with serious environmental and social consequences. Using Nairobi as an example of a rapidly urbanizing African city, we studied the dynamics of land use and land cover change using satellite data and addressed the need for models and urban management tools that can guide sustainable urban planning policies. Cellular Automata, which integrate biophysical factors with dynamic spatial modeling, are used in this study. The model was calibrated and tested using time series of urbanized areas derived from land use/cover maps, produced from remotely sensed imagery, with future urban growth projected to 2030. Model assessment results showed high levels of accuracy, indicating that simulation findings were realistic, thereby confirming the effectiveness of the model. Results further showed that the model is a useful and effective tool to foresee the spatial consequences of planning policies in the context of many African cities. The forecast for Nairobi showed unsustainable sprawl. 相似文献
12.
Andrew J. Krmenec 《The Professional geographer》1991,43(1):60-67
Local governments are under pressure to develop alternative revenue sources to their already strapped property tax bases. Throughout the 1970s, municipal governments nationwide restructured their local taxes by substituing sales tax for property tax revenue. A tax accounting model identified two sources of sales-for-property tax substitution: changes in the tax rates and normal economic growth and decline. Most of the sales-for-property tax substitution experienced in Illinois city finance was attributable to economic change. The critical determinant of this substitution appreared to be the municipality's share of the regional retail market. Cities in higher density metropolitan areas were less likely to experience sales-for-property tax substitution through economic growth than those cities in lower density, less competitive environments. 相似文献
13.
With the possibility of future fresh water shortages increasing, a methodology that incorporates climatic and anthropogenic factors is needed. This research estimates future water availability in the Lower Cape Fear basin using changes in climate, land use, and population growth. The USGS Thornthwaite monthly water balance model is used with estimates of climate change and land use change parameters to assess future water resources based on predicted monthly fluxes of the water balance.The southern United States is a rapidly growing region. Trends present in the population data are used to produce future estimates of population for the basin. Precipitation and temperature estimates based on Intergovernmental Panel on Climate Change (IPCC) predictions and current climatology are inputs to the model. Projected increases in impervious surface cover due to population growth and urbanization are incorporated through the model runoff factor. Water stress indicators are used to categorize the sub-watersheds as water rich, water stressed, or water scarce. Scenarios incorporating regional predictions of climate change indicate a decrease in summer soil moisture minima and increases in summer water deficits. Ensemble runs indicate a shift toward water stress in the Lower Cape Fear River basin, due to a warming climate as well as increased demand. While climate change has a significant impact on water resources, population growth was found to have the most substantial impact. The methods and findings have application to water managers at local and regional levels. 相似文献
14.
新疆人口变动对生态环境的未来影响趋势与协调发展对策——以塔里木河流域为例 总被引：2，自引：0，他引：2
通过对一个典型干旱区内陆河流域——新疆塔里木河流域的人口与生态环境演变之间互动机制的分析, 用系统动力学方法建立了该流域的动态仿真模型。通过模型的多方案运行, 观察未来该流域各种人口变动条件下生态环境的可能演变后果, 从而提出有利于流域生态环境的合理人口变动条件与政策, 为有关部门提供决策参考。 相似文献
15.
The ongoing encroachment of urban land into natural landscapes has resulted in the degradation of ecosystems throughout Europe. Understanding why the share of urban land has increased is important for managing urban growth and maintaining ecosystem services. We estimate a model of landscape change that integrates geospatial and socioeconomic data in a spatial autoregressive model to explain the variance in urban growth observed in Germany between 2000 and 2006. In doing so, we test several determinants of urbanization identified by theoretical frameworks from landscape ecology and economics, including landscape pattern and transit infrastructure. The results show that despite planning guidelines and policies to promote dense development, urban growth has been extensive. Regions with a high degree of fragmented land and the prevalence of environmental amenities are characterized by particularly strong growth, pointing to challenges in crafting landscape policies that balance economic development with environmental conservation. 相似文献
16.
城市空间增长与人口密度变化之间的关联关系 总被引：2，自引：1，他引：1
探究城市空间增长与人口密度变化之间的关联关系是城市可持续发展研究的基础,对制定有效的土地政策、促进城市紧凑发展具有重要意义。选取中国和欧洲23个人口100万以上城市作为研究样本,采用1990年、2000年和2014年3期土地利用数据和人口数据,计算各时段样本城市空间增长速率,建立城市紧凑度指标,并将城市空间增长方式划分为紧凑型、保持型和蔓延型,进一步探讨了样本城市的空间增长特征、人口密度变化特征及两者之间的关系。主要结论为：① 人口密度降低这一现象普遍存在于中国和欧洲城市,中国城市人口密度相对较高且降低速率较快,欧洲城市人口密度相对较低且降低速率较慢;1990—2014年中国城市半径的增长速率明显快于欧洲城市半径的增长速率。城市空间增长速率与人口密度变化速率呈现强负相关关系（Pearson相关系数为-0.693）;② 1990—2000年中欧城市主要以紧凑型方式增长。2000—2014年中国城市主要以蔓延型方式增长,且人口密度随时间下降的速率加快;欧洲城市主要以紧凑型和保持型方式增长,人口密度降低速率减小;③ 紧凑型的空间增长方式并不一定会带来人口密度的升高,但会减缓人口密度下降的速率。中欧城市对比分析表明,城市维持紧凑型空间增长方式,则城市人口密度随时间下降速率减慢;而空间增长方式由紧凑型转为蔓延型,将加剧城市人口密度随时间下降。 相似文献
17.
This paper analyzes the demographic processes that contribute to population growth and redistribution in a multiregional system using a new method. The method incorporates a historical perspective that can be used to trace dynamic population processes as they evolve over time. It uses an open multiregional projection model framework in identifying the contributions to regional growth made by each of the principal demographic components of change: fertility, mortality, immigration, emigration, in-migration, and out migration. At the same time, the method recognizes the importance of disaggregating the native-born and foreign-born populations. Available public data and indirect estimation techniques are used to develop the data inputs for the projection model, with which the regional population changes for each 5-year period between 1950 and 1990 were reconstructed. Regional growth rates for the foreign-born and native-born populations are partitioned into the separate demographic components of change, and the projection model identifies the separate contributions to regional growth made by each population. This allows a direct comparison of the impact of immigration with those of corresponding native-born contributions effected through internal migration and natural increases. Finally, the application of the method allows the identification of the contribution that 'recent' (post-1965) immigrant cohorts have made to the composition of the youngest age groups in each region, and also to simulate the impacts of zero immigration scenarios on regional growth. 相似文献
18.
城市土地利用结构影响因素的通径分析——以重庆市为例 总被引：7，自引：2，他引：5
精确刻画城市用地结构与影响因素间的直接和间接效应对城市土地利用宏观调控和用地结构优化具有重要的意义。采用通径分析法,对重庆市城市土地利用结构与影响因素之间的关系进行定量厘定,结果表明:①人口增长对居住用地比例的直接效应最大(0.446),其通过经济发展、产业结构变化和交通基础设施发展的间接效应分别为-0.189、0.221、-0.042;经济发展、产业结构变化通过人口增长对居住用地的间接效应较大(0.420、0.309)。②产业结构变化、经济发展对工业用地比例的直接效应为-1.357和1.236,对公共服务用地比例的直接效应为1.387、-1.100;人口增长通过经济发展对工业用地比例和公共服务用地比例的间接效应分别为1.163、-1.036,作用方向相反。③经济发展、交通基础设施发展和产业结构变化是影响绿地比例的重要因素;人口增长通过经济发展后的间接效应(0.451)显著于直接效应(-0.117)。④经济发展、产业结构变化和人口增长及三者的耦合作用是影响城市用地结构的主要因素。 相似文献
19.
产业结构变动对区域经济增长贡献的演变研究 总被引：16，自引：1，他引：15
产业结构变动是影响区域经济增长的重要因素。采用多部门经济模型和基于统计角度的GDP产业结构贡献度测算方法,分析1953--2003年河南省产业结构变动对经济增长的贡献,发现产业结构变动对区域经济增长的贡献逐渐下降,大体上服从Growth函数,具有长、短波复合变动规律,产业结构调整存在着阶段性和周期性特点。产业结构变动对区域经济增长的贡献在减小,经济增长的稳定性在增加,人为调整产业结构和市场与经济自身调节产业结构具有不同的效用和特点。 相似文献
20.
Several factors contribute to on-going challenges of spatial planning and urban policy in megacities, including rapid population shifts, less organized urban areas, and a lack of data with which to monitor urban growth and land use change. To support Mumbai's sustainable development, this research was conducted to examine past urban land use changes on the basis of remote sensing data collected between 1973 and 2010. An integrated Markov Chains–Cellular Automata (MC–CA) urban growth model was implemented to predict the city's expansion for the years 2020–2030. To consider the factors affecting urban growth, the MC–CA model was also connected to multi-criteria evaluation to generate transition probability maps. The results of the multi-temporal change detection show that the highest urban growth rates, 142% occurred between 1973 and 1990. In contrast, the growth rates decreased to 40% between 1990 and 2001 and decreased to 38% between 2001 and 2010. The areas most affected by this degradation were open land and croplands. The MC–CA model predicts that this trend will continue in the future. Compared to the reference year, 2010, increases in built-up areas of 26% by 2020 and 12% by 2030 are forecast. Strong evidence is provided for complex future urban growth, characterized by a mixture of growth patterns. The most pronounced of these is urban expansion toward the north along the main traffic infrastructure, linking the two currently non-affiliated main settlement ribbons. Additionally, urban infill developments are expected to emerge in the eastern areas, and these developments are expected to increase urban pressure. 相似文献