首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
生态阻力面模型构建及其在城市扩展模拟中的应用   总被引:13,自引:0,他引:13  
本文将城市扩展视为城市用地克服生态阻力向外扩散的过程,基于最小累积阻力模型(MCR)进行方法创新,在模型中引入不同等级源的相对阻力因子,并考虑生态障碍对于城市扩展的刚性约束,构建适合于城市扩展模拟的生态阻力面模型(UEER)。在此基础上,利用广州市土地利用第二次调查数据、遥感影像数据、DEM数据以及其他生态要素相关数据,通过源的确定与分级、基面阻力综合评价、UEER模型运算等步骤,构建了广州市城市扩展的生态阻力面,并用于模拟城市用地扩展至不同规模情景时的空间分布及边界。结果表明:①通过UEER模型生成的生态阻力面能够综合反映城市扩展水平过程所需克服的生态阻力,因此能够反映生态约束下城市扩展的空间运动趋势,可以用于城市扩展模拟。②与基于MCR模型的模拟结果相比,基于UEER模型的模拟结果更加符合实际并体现生态保护的要求。从城市扩展的规模与强度控制看,模拟结果更加符合实际需求,并体现政策调控方向。从城市形态以及与生态要素的关系看,一些重要的生态要素在快速城市化进程中能够得以保留,同时生态障碍作为生态隔离,能够有效地防止城市的蔓延式扩展,从而使城市扩展表现出明显的组团式特征。  相似文献   

2.
区域尺度城市增长时空动态模型及其在京津唐都市圈应用   总被引:3,自引:0,他引:3  
Dynamic urban expansion simulation at regional scale is one of the important re-search methodologies in Land Use/Cover Change (LUCC) and global environmental change influenced by urbanization.However,previous studies indicate that the single urban expan-sion simulation for future scenarios at local scale cannot meet the requirements for charac-terizing and interpreting the interactive mechanisms of regional urbanization and global en-vironmental change.This study constructed a regional Dynamic Urban Expansion Model (Reg-DUEM) suitable for different scenarios by integrating the Artificial Neural Network (ANN) and Cellular Automaton (CA) model.Firstly we analyzed the temporal and spatial character-istics of urban expansion and acquired a prior knowledge rules using land use/cover change datasets of Beijing-Tianjin-Tangshan metropolitan area.The future urban expansion under different scenarios is then simulated based on a baseline model,economic models,policy models and the structural adjustment model.The results indicate that Reg-DUEM has good reliability for a non-linear expansion simulation at regional scale influenced by macro-policies.The simulating results show that future urban expansion patterns from different scenarios of the metropolitan area have the tremendous spatio-temporal differences.Future urban ex-pansion will shift quickly from Beijing metropolis to the periphery of Tianjin and Tangshan city along coastal belt.  相似文献   

3.
China is now experiencing rapid urbanization. Powerful tools are required to assess its urban spatial policies before implemented toward a more competitive and sustainable development paradigm. This study develops a Land Use Transport Interaction(LUTI) model to evaluate the impacts of urban land-use policies on urban spatial development. The model consists of four sub-models, i.e., transport, residential location, employment location and real estate rent sub-models. It is then applied to Beijing metropolitan area to forecast the urban activity evolution trend based on the land-use policies between 2009 and 2013. The modeling results show that more and more residents and enterprises in the city choose to agglomerate on outskirts, and new centers gradually emerge to share the services originally delivered by central Beijing. The general trend verifies the objectives of the government plan to develop more sub-centers around Beijing. The proposed activity-based model provides a distinct tool for the urban spatial policy makers in China. Further research is also discussed at the end.  相似文献   

4.
5.
中国城市扩展对气温观测的影响及其高估程度(英文)   总被引:2,自引:1,他引:2  
Since the implementation of the reform and opening up policy in China in the late 1970s, some meteorological stations ’entered’ cities passively due to urban expansion. Changes in the surface and built environment around the stations have influenced observations of air temperature. When the observational data from urban stations are applied in the interpolation of national or regional scale air temperature dataset, they could lead to overestimation of regional air temperature and inaccurate assessment of warming. In this study, the underlying surface surrounding 756 meteorological stations across China was identified based on remote sensing images over a number of time intervals to distinguish the rural stations that ’entered’ into cities. Then, after removing the observational data from these stations which have been influenced by urban expansion, a dataset of background air temperatures was generated by interpolating the observational data from the remaining rural stations. The mean urban heat island effect intensity since 1970 was estimated by comparing the original observational records from urban stations with the background air temperature interpolated. The result shows that urban heat island effect does occur due to urban expansion, with a higher intensity in winter than in other seasons. Then the overestimation of regional air temperature is evaluated by comparing the two kinds of grid datasets of air temperature which are respectively interpolated by all stations’ and rural stations’ observational data. Spatially, the overestimation is relatively higher in eastern China than in the central part of China; however, both areas exhibit a much higher effect than is observed in western China. We concluded that in the last 40 years the mean temperature in China increased by about 1.58℃, of which about 0.01℃ was attributed to urban expansion, with a contribution of up to 0.09℃ in the core areas from the overestimation of air temperature.  相似文献   

6.
从土地供给角度建立城市扩展模型,可以为城市扩展模拟研究提供有效补充。城市扩展生态阻力面模型是这一领域的新进展,在最小累积阻力面模型的基础上增加了绝对生态约束和扩展源等级的改进。在城市扩展生态阻力面模型的基础上,进一步加入了城市空间区位条件因素,包括城市间空间相互作用和道路交通条件两项因子,以反映其对城市空间扩展的影响。从而构建了综合考虑城市扩展的推力、阻力和外部吸引力的城市扩展模型。以新疆玛纳斯县城及其周边区域为例,利用构建的模型进行实证研究。结果表明,改进的模型取得了较好的应用效果,反映了城市扩展的推力、阻力和外部吸引力的综合作用,为城市扩展模拟提供了新方法。  相似文献   

7.
The objective of this study is to quantitatively evaluate Tropical Rainfall Measuring Mission(TRMM) data with rain gauge data and further to use this TRMM data to drive a Distributed Time-Variant Gain Model(DTVGM) to perform hydrological simulations in the semi-humid Weihe River catchment in China.Before the simulations,a comparison with a10-year(2001-2010)daily rain gauge data set reveals that,at daily time step,TRMM rainfall data are better at capturing rain occurrence and mean values than rainfall extremes.On a monthly time scale,good linear relationships between TRMM and rain gauge rainfall data are found,with determination coefficients R~2 varying between 0.78 and 0.89 for the individual stations.Subsequent simulation results of seven years(2001-2007)of data on daily hydrological processes confirm that the DTVGM when calibrated by rain gauge data performs better than when calibrated by TRMM data,but the performance of the simulation driven by TRMM data is better than that driven by gauge data on a monthly time scale.The results thus suggest that TRMM rainfall data are more suitable for monthly streamflow simulation in the study area,and that,when the effects of recalibration and the results for water balance components are also taken into account,the TRMM 3B42-V7 product has the potential to perform well in similar basins.  相似文献   

8.
In the urbanizing world,the Yangtze Delta Region (YDR) as one of the most developed regions in China,has drawn a lot of the world’s attention for the remarkable economic development achieved in the past decades.Nevertheless,the rapid economic development was certain to be accompanied by unprecedented consumption and loss of natural resources.Therefore,the analysis of the ecological situation and driving factors of environmental impact was of great significance to serve the local sustainable development decision-making and build a harmonious society.In this paper,the ecological footprint (EF) was taken as the index of the ecological environmental impact.With the help of Geographic Information System (GIS),we studied the spatiotemporal change of ecological footprint at two scales (region and city) and assessed urban sustainable development ability in YDR.Then we discussed the driving factors that affected the change of ecological footprint by the Stochastic Impacts by Regression on Population,Affluence,and Technology (STIRPAT) model.The results showed that increasing trends of regional ecological footprint during 1998-2008 (1.70-2.53 ha/cap) were accompanied by decreasing ecological capacity (0.31-0.25 ha/cap) but expanding ecological deficit (1.39-2.28 ha/cap).The distribution pattern of ecological footprint and the degree of sustainable development varied distinctly from city to city in YDR.In 2008,the highest values of ecological footprint (3.85 ha/cap) and the lowest one of sustainable development index (SDI=1) in YDR were both presented in Shanghai.GDP per capita (A) was the most dominant driving force of EF and the classical EKC hypothesis did not exist between A and EF in 1998-2008.Consequently,increasing in ecological supply and reducing in human demand due to technological advances or other factors were one of the most effective ways to promote sustainable development in YDR.Moreover,importance should be attached to change our definition and measurement of prosperity and success.  相似文献   

9.
China is now experiencing rapid urbanization. Powerful tools are required to assess its urban spatial policies before implemented toward a more competitive and sustainable development paradigm. This study develops a Land Use Transport Interaction(LUTI) model to evaluate the impacts of urban land-use policies on urban spatial development. The model consists of four sub-models, i.e., transport, residential location, employment location and real estate rent sub-models. It is then applied to Beijing metropolitan area to forecast the urban activity evolution trend based on the land-use policies between 2009 and 2013. The modeling results show that more and more residents and enterprises in the city choose to agglomerate on outskirts, and new centers gradually emerge to share the services originally delivered by central Beijing. The general trend verifies the objectives of the government plan to develop more sub-centers around Beijing. The proposed activity-based model provides a distinct tool for the urban spatial policy makers in China. Further research is also discussed at the end.  相似文献   

10.
近年来,耕地撂荒在全球众多国家和地区都呈现出严重的发展趋势,耕地撂荒已成为土地利用变化领域重要的研究问题之一。准确解析耕地撂荒的影响因素,构建科学的模型模拟耕地撂荒的态势,合理评估耕地撂荒的潜在影响,成为耕地撂荒研究关注的焦点问题。本文在全面总结耕地撂荒相关研究的基础上,综述了耕地撂荒的自然、人文与政策驱动因素,梳理了耕地撂荒模拟的主要模型及其优缺点。在此基础上,讨论了耕地撂荒的主要生态效应,并展望了相关研究未来的发展方向。研究发现:(1)对于耕地撂荒的影响因素,需要格外关注劳动力价格变化、劳动力老龄化对于耕地撂荒的影响;(2)对于耕地撂荒模拟模型,需要加强基于农户的撂荒机理模型与宏观大尺度撂荒预测模型的研制;(3)对于耕地撂荒的生态环境效应,除了需要关注耕地撂荒对粮食生产以及生态系统方面的影响外,还需要重视耕地撂荒对景观文化方面的影响。  相似文献   

11.
Employing DEA model and Malmquist productivity index, this paper probes into the urban efficiencies of 24 typical resources-based cities in China and their changes from 2000 to 2008. The research finds that the overall efficiencies of the resources-based cities are just at a general level, and only a few of them reach the optimal level. The scale efficiency is the major determining factor of the achievement of overall efficiency, the effect of which, never-theless, is reducing. From the perspective of classification characteristics, the re-sources-based cities in northeastern region have been in the front rank in terms of overall efficiency, pure technical efficiency and scale efficiency. There is a certain positive correlation between urban population scale and urban efficiency. The analysis of urban efficiency changes shows that the changes in overall efficiency of resources-based cities from 2000 to 2008 had a weak improving tendency. Both the technical change index and productivity change index decreased, indicating that the urban efficiency did not improve during this pe-riod, and the tendency of technical recession and productivity decline was obvious. In terms of the classification of urban efficiency changes, the urban overall efficiency improved in each of the four regions from 2000 to 2008, among which western region witnessed the greatest increase. Cities with different resource types have improved their urban overall efficiencies except steel-based cities. The urban overall efficiency increased in resources-based cities of different scales, with greater improvement in small and medium-sized cities than in big cities.  相似文献   

12.
景观扩张指数及其在城市扩展分析中的应用   总被引:15,自引:1,他引:15  
刘小平  黎夏  陈逸敏  秦雁  李少英  陈明辉 《地理学报》2009,64(12):1430-1438
景观指数是定量分析景观格局的一种常用手段,但目前大部分景观指数,往往只侧重于对景观斑块或格局的几何特征进行简单分析和描述.忽略了景观格局动态变化过程的信息.缺乏将景观空间分布格局与其变化过程相结合的深入研究.作者提出了一种新的景观指数一景观扩张指数(Landscape Expansion Index,LEI),与传统的景观指数相比,LEI包涵了景观格局的过程信息,可用来分析两个或多个时相景观格局的动态变化.而传统景观指数则只能反映某一时相景观格局的信息.将景观扩张指数应用于东莞市1988-2006年期间的城市景观扩张过程中,研究结果表明.LEI能够很好的识别城市扩张的三种类型一填充式、边缘式以及飞地式.此外,通过对东莞市城市扩张过程LEI的变化分析,发现东莞市城市扩张规律与城市增长相位理论是相符合的.  相似文献   

13.
由于二氧化碳的大量排放,导致生态环境急剧恶化,全球各国对碳排放量的关注度越来越高.推出碳金融衍生品、完善碳交易体系是促进碳减排的重要手段,而合理的碳金融衍生品定价是推出相关金融产品的基础。本文首次采用双侧伽马分布拟合碳配额收益率序列,得到碳配额价格的波动率并对期权定价模型进行优化,最终求得了碳期权价格。结果表明:碳配额收益率序列近似服从双侧伽马分布,而且此模型用于碳期权定价具有合理性。随后,综合考虑连涨、连跌收益率之间的关系及成交量对价格的影响,利用双侧伽马分布推导出价格涨跌条件概率的公式,进行了数值验证。因此,双侧伽马分布在碳交易中可用于期权定价和价格涨跌概率推断。  相似文献   

14.
Groundwater is the most appropriate and widely used source of drinking water,which is increasingly threatened by pollution from industrial and agricultural activities.To check the severity of the problem,156 groundwater samples were collected from various depths(60-110 ft) of 52 different localities in Faisalabad city,the third largest metropolis in Pakistan,and analyzed for the metals(Zn,Cu,Cd,Ni,Pb,Mn and Fe) concentration in 2009.Quantification was done by using Flame Atomic Absorption Spectrophotometer technique and the results were compared with WHO standards for drinking water quality.Results showed that the levels of Cu,Mn and Fe were below the WHO standards while the concentrations of Zn,Cd,Ni and Pb were above the recommended levels of safe drinking water.Correlation analysis among the occurrence of these heavy metals revealed a highly significant and positive correlation of Mn with Zn and Fe.A significant and positive correlation of Cd was also found with Cu and groundwater depth showing that there is strong association between Cu-Cd pair and that the Cd concentration varies with depth of groundwater in the study area.Regional patterns of heavy metals occurrence were mapped using Geographical Information System(GIS) for the identification and demarcation of risk areas.The concentration maps may be used by policymakers of the city to mitigate groundwater pollution.  相似文献   

15.
MTCLIM模型是许多生态、生理模型的分析工具。它能解释模型的结果,分析一些生态、水文过程在不同气候条件下的变化趋势,也是其它模型的辅助管理工具,辅助建立不同环境条件下的生态管理方案。本文介绍了该模型的基本原理及其各变量较详细的计算方法,概述其研究历史及发展现状,及模型应用的几个重要方面及其发展趋势。  相似文献   

16.
我国城市扩张、粮食保障和能源转型形势严峻,如何挖掘城市建成环境的绿色生产潜力、探索一条通过粮食生产和太阳能利用节约土地空间并缓解生态压力的新途径?本文不同于以往生态补偿研究大多以重点生态功能区为对象或以财税补偿机制为手段,而是创新性地建立了一种城市空间内部的生态补偿机制。本文提出城市“绿色生产性面积”作为一种从城市生态学角度来衡量城市生态承载力提升潜力的方法,它基于将城市绿色资源收入换算成相同条件下它们所能节约的生态足迹面积。首先,通过类型学方法建立绿色生产补偿策略;其次,进行城市建成环境的全要素空间清查及其绿色生产潜力分析;最后,建立不同绿色生产的生态节地效益统一核算标准,并转换为绿色生产性土地面积指标。以天津市南开区学府街道为例,通过可利用的屋顶及闲置用地进行绿色生产,补充了该区12%的建筑所占用的自然土地所能提供的生态承载力。  相似文献   

17.
In this study, we adopt kernel density estimation, spatial autocorrelation, spatial Markov chain, and panel quantile regression methods to analyze spatial spillover effects and driving factors of carbon emission intensity in 283 Chinese cities from 1992 to 2013. The following results were obtained.(1) Nuclear density estimation shows that the overall average carbon intensity of cities in China has decreased, with differences gradually narrowing.(2) The spatial autocorrelation Moran's I index indicates significant spatial agglomeration of carbon emission intensity is gradually increasing; however, differences between regions have remained stable.(3) Spatial Markov chain analysis shows a Matthew effect in China's urban carbon emission intensity. In addition, low-intensity and high-intensity cities characteristically maintain their initial state during the transition period. Furthermore, there is a clear "Spatial Spillover" effect in urban carbon emission intensity and there is heterogeneity in the spillover effect in different regional contexts; that is, if a city is near a city with low carbon emission intensity, the carbon emission intensity of the first city has a higher probability of upward transfer, and vice versa.(4) Panel quantile results indicate that in cities with low carbon emission intensity, economic growth, technological progress, and appropriate population density play an important role in reducing emissions. In addition, foreign investment intensity and traffic emissions are the main factors that increase carbon emission intensity. In cities with high carbon intensity, population density is an important emission reduction factor, and technological progress has no significant effect. In contrast, industrial emissions, extensive capital investment, and urban land expansion are the main factors driving the increase in carbon intensity.  相似文献   

18.
城市经济脆弱性模拟评估系统的构建及其应用   总被引:2,自引:1,他引:2  
经济脆弱性评价是风险评估的重要步骤和制定有效防灾减灾规划的前提条件,是应急管理和灾后恢复的重要依据。本文提出了一个微观尺度的城市经济脆弱性评估模型,从各类企业的空间布局及其行业经济特征入手,综合考虑企业属性、产业易损性、产业重要性、经济密度等因素,并在此基础上构建了城市经济脆弱性模拟评估系统,以北京市海淀区为案例区对上述模型方法进行了检验。结果表明,城市经济脆弱性评估方法及系统的构建有利于决策者准确把握城市经济脆弱性的分布状况,甄别风险地区和确定风险级别,为城市灾害风险管理提供了可靠依据。系统的运行取得了良好的效果,在辅助决策方面有很好的应用前景,也为城市灾害管理的信息化提供了有益的探索。  相似文献   

19.
改进的BTOPMC模型及其在水文模拟中的应用   总被引:2,自引:0,他引:2  
In this paper, a grid-based distributed hydrological model BTOPMC (Block-wise use of TOPMODEL) is introduced, which was developed from the original TOPMODEL. In order to broaden the model's application to arid regions, improvement methodology is also implemented. The canopy interception and soil infiltration processes were incorporated into the original BTOPMC to model event-based runoff simulation in large arid regions. One designed infiltration model with application of time compression approximation method is emphasized and validated for improving model's performance for event hydrological simulations with a case study of Lushi River basin.  相似文献   

20.
随着中国的“黄河流域高质量发展”政策的实施,黄土高原未来的城市增长将进一步快速发展。然而,区域尺度城市增长的时空动态模拟研究还很有限。基于历史土地利用数据和SLEUTH模型模拟,得到1995-2050年1-km分辨率的城市覆盖数据,并利用指标化空间制图方法发展了一种城市增长量化与制图的集成分析方法。在黄土高原的研究表明:城市发展政策、自然环境和行政职能影响了不同等级城市的城市增长速度和空间格局;15个地级市和省会城市在2050年的总面积大约是1995年的8.12倍,1995-2015年和2015-2050年城市总体增长率分别为5.97%和3.2%;总体而言,1995-2015年的城市增长模式主要是跨越式增长,21世纪30年代以后,边缘增长模式将成为城市增长的主导模式,内生型增长模式仅对兰州、西宁等个别河谷型城市发展具有贡献作用。基于高分辨率地图集的多层次城市增长时空变化分析可为区域城市规划和可持续城市管理提供重要信息。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号