中国科学院生态环境研究中心机构知识库
Advanced  
RCEES OpenIR  > 城市与区域生态国家重点实验室  > 学位论文
题名: 典型城市群空间扩张及其对生态系统净初级生产力的影响
作者: 虞文娟1
学位类别: 博士
答辩日期: 2017-05
授予单位: 中国科学院大学
授予地点: 北京
导师: 周伟奇
关键词: 城市群 ; 回溯 ; urban megaregion,backdating,object-based image analysis, spatiotemporal pattern of urban expansion, net primary productivity (NPP) ; 面向对象图像分析 ; 空间扩张模式 ; 净初级生产力
其他题名: Urban expansion in megaregions and its impacts on Ecosystem Net Primary Productivity
学位专业: 生态学
中文摘要: 区域城市化,即以城市群为主体形态的城市化是我国新型城镇化发展战略的 主导方向之一。未来 20-30年,我国将规划建设 23个规模不一、功能不同的城 市群。短期且快速的城市化,不仅给城市本身的生态环境带来严重影响,还对城 市周边区域产生一定的影响,造成区域性的生态环境问题。因此,如何减小区域 城市化对生态环境的影响,成为研究的热点。定量解析我国城市群空间发展模式 特征及其演变规律,研究城市群空间发展模式对生态环境的影响具有重要的科学 意义,并可为我国区域发展规划与管理提供科学的支撑。 本论文选取京津冀和长三角两个典型城市群为主要研究对象,以生态系统净 初级生产力(NPP)为例,定量分析城市群空间扩张模式及其对生态系统的影响。 首先,针对分类精度低和效率低的问题,探索了适用于城市群这种大空间范围的 土地覆盖分类及变化分析方法。基于这一方法,获取了两大城市群 1984年、1990 年、2000年和 2010年的土地覆盖分类专题图,并从城市群和城市两个尺度,以 及城市扩张幅度和速度、城市扩张均衡性和城市空间扩张形态三个方面,定量解 析了城市群空间扩张模式。在此基础上,从土地覆盖变化对 NPP的影响,城市 空间扩张方式引起的景观破碎度变化与 NPP的相关关系两个方面,进一步探讨 了 2000年-2010年区域城市化对生态系统 NPP的影响。研究的主要结果和结论 如下: (1)本研究提出的新方法——结合回溯和面向对象的分类及变化分析方法, 适用于大空间范围的土地覆盖分类及变化分析研究。以遥感影像为基础,该方法 将地物的空间几何信息及先验知识用于分类和变化分析,可有效地减少分类错误, 分类总体精度从 63.99%提高至 84.33%。同时,采用回溯的概念,该方法仅对发 生变化的区域进行分析,而变化区域占全局影像的比例通常不足 20%,因此分类 及变化分析的效率得以提高。这种效率的提高对诸如城市群、国家甚至全球这种 大空间范围的土地覆盖及变化分析研究非常重要。 (2)京津冀和长三角城市群城市空间扩张模式差异显著。①1984-2010年, 京津冀城市群始终保持双中心的格局,而长三角城市群则从单中心转变为多中心 的格局。②京津冀和长三角都经历了快速的城市扩张。但城市群内部,城市扩张 幅度和速度差异明显。在京津冀城市群内部,大规模城市建设用地扩张幅度和速 度远高于中小规模城市。不同规模城市间扩张差异略有增大,相同规模城市间扩 张差异略有减小。而长三角内部,中小规模城市与大规模城市相似,具有较大面 积和较快速度的建设用地扩张。不同规模和相同规模城市间扩张差异大幅减小, 趋于均衡。③空间扩张方式分析结果显示,城市群空间扩张方式与单一城市空间 扩张方式规律一致,符合“扩散-合并”原理。发展快速的京津冀城市群以边缘扩 张方式为主,发展较为成熟的长三角城市群以边缘扩张和内部填充型为主。随着 城市群的发展,城市扩张斑块大小趋于相似。④城市特征对城市空间扩张方式的 影响分析显示,城市的城市群归属显著影响城市扩张形态。随着城市规模的扩大, 蛙跳型扩张方式占比下降,城市扩张速度的提高,则使边缘扩张方式占比上升。 (3)城市扩张引起的土地覆盖变化导致生态系统 NPP显著下降。同时,城 市空间扩张会导致景观破碎度的变化,进而影响生态系统 NPP,但是不同的城市 空间扩张方式,对景观破碎度的影响不同,因而对生态系统 NPP的影响也不同。 研究结果显示:①京津冀和长三角城市群 NPP空间分布分异明显,林地和耕地 NPP均值显著高于草地和建设用地 NPP均值。虽然总体上,城市群 NPP年均值 变化稳定,但局部地区变化剧烈。城市原有建成区 NPP上升趋势明显,但新增 建成区 NPP呈显著下降趋势。②2000年-2010年,城市扩张使大量植被覆盖用 地转变为建设用地。尤其是耕地,转变面积占新增建设用地面积比分别为 83.11% 和 87.58%。林地、草地和耕地转变为建设用地后,NPP呈显著下降趋势,表明 城市扩张对生态系统 NPP具有显著的负影响。③边缘扩张型比例的增长导致耕 地景观破碎度提高。当控制建设用地面积比后,京津冀及长三角均表现出边缘扩 张型面积比与耕地平均斑块大小变化呈显著负相关,与耕地斑块密度变化呈显著 正相关。④耕地景观破碎度的提高导致耕地 NPP显著下降。景观破碎度变量与 NPP的偏相关分析显示,当控制土地覆盖类型面积比后,耕地平均斑块大小与 NPP显著正相关,耕地斑块密度与 NPP呈显著负相关关系。
英文摘要: Urban megaregion has became a major form of Chinese New-Type urbanized strategy. In the future 20~30 years, Chinese central government plans to build an urban system consists of 23 urban megaregions with different size and functions. Along with the urban megaregional development, some ecological and environmental issues not only impact the urban area and well beyond the urban region, become regionalization. Therefore, study on 1) the spatiotemporal pattern of urban expansion and 2) the influence of urban expansion on the ecosystem in urban megaregion are crucial for Chinese urban planning and management. We chose two largest urban megaregions, Beijing-Tianjin-Hebei (hereinafter referred to as BTH) and Yangtze River Delta (hereinafter referred to as YRD) urban megaregions as our study areas, and analyzed the urban explosion and the consequances on ecosystem net primary productivity (NPP) in the urban megaregion. To explore the spatiotemporal pattern of urban expansion and its impacts on the ecosystem in urban megaregion, the accurate land use land cover (LULC) classification and change analysis information must be firstly quantified. We presented a new approach, integrates the backdating and an object-based method and tested the classified accuracy and efficiency by comparing to the traditional approach, integrates the backdating and pixel based method. We then generated the LULC maps of the BTH and YRD in 1984, 1990, 2000 and 2010 by the better classification approach. Base on the LULC maps, we quantified the spatiotemporal pattern of urban expansion by analyzing three aspects: (1) the magnitude and rate of urban expansion, (2) the inequality of urban expansion, and urban expansion morphological model at both the regional and city levels. We further analyzed the impacts of urban megaregion growth on the ecosystem NPP from two aspects: (1) the consequences of vegetated land transformation on NPP, and (2) the influence of urban expansion morphology on ecosystem NPP by analyzing the relationship among the urban expansion morphology, landscape fragmentation and ecosystem NPP. Our results described as below: (1) LULC classification and change analysis approach for urban megaregion The object-based backdating approach, we presented in this study, achieved high accuracy for LULC classification and change analysis by comparing to the traditional approach, pixel-based backdating approach (overall accuracy, 84.33% vs. 63.99%) In addition, the object-based backdating approach greatly improved the efficiency for LULC classification and change analysis because this approach only performs the analysis in the area with change. The area proportion with change was generally less than 20% of the entire study area. Such efficiency improvement is mostly important for the large area study, such as urban megaregion, national and global areas. (2) The spatiotemporal pattern of urban expansion in BTH and YRD In the past three decades, the BTH retained a double-nuclear pattern with a clustered growth of developed land around the cities of Beijing and Tianjin. Comparatively, the urban pattern of the YRD changed from single nuclear to multiple nuclear with dispersive landscape. Both the BTH and YRD experienced a rapid urban expansion. However, the magnitude and rate of urban expansion of the cities within the urban megaregion have difference. In the BTH, the magnitudes and rates of urban expansion were greater in larger cities than in medium- and small-size cities. The differnces of urban expansion between different size cities slightly increased and that between the same size cities slightly decreased. In contrast, the magnitudes and rates of urban expansion in medium- and small-size cities were similar with large size cities in the YRD. The differences of the urban expansion between different size and same size decreased. Reults of the morphological models of urban expansion showed the urban expansion process of the urban megaregion is consistent with that of a single city, which it follows the “diffusion - coalescence” hypothesis. Along with the urban megaregional development, patch size of the new developed land became similar. The adminiatrative division of the city significantly influenced the morphological model of urban expansion. Small-size cities were more likely to develop the leapfrogging model, while cities with rapid expansion tended to develop the edge-expansion model. (3) The impacts of urban expansion on the ecosystem net primary productivity The land cover changes caused by urban expansion decreased the ecosystem NPP. At the mean time, the landscape segmentation caused by urban expansion also decreased the NPP. The spatial characteristics of ecosystem NPP varied from different LULC type, which the annual mean value of NPP in the forest and farmland were mostly higher than that in the grass and developed land in both the BTH and YRD. Although the mean value of NPP was stable at the megaregional scale, the change trend of NPP was varied greatly in some local areas. Tthe NPP change trend in the original urban area increased obviously, but that in the new build-up area decreased significantly. In 2000-2010, urban expansion mostly consumed the farmland, which the percentage of the conversional farmland to the new developed land were 83.11% and 87.58% in the BTH and YRD, respectively. The vegetative land change to developed land significantly decreased the ecosystem NPP. The area percentge of edge-expansion model had significantly negative correlation with mean patch size (MPS) change of farmland and significantly positive correlation with patch density (PD) change of farmland by controlling the percentage of developed land change. The further partial correlation analysis showed the MPS of farmland had significant positive relationship with the ecosystem NPP, and the PD of farmland had negative relationship with the ecosystem NPP by controlling the area percentage of forest, grass, farmland and developed land. Our results indicated the edge-expansion model segmented the landscape of farmland and further impacts on the ecosystem NPP.
内容类型: 学位论文
URI标识: http://ir.rcees.ac.cn/handle/311016/38736
Appears in Collections:城市与区域生态国家重点实验室_学位论文

Files in This Item:
File Name/ File Size Content Type Version Access License
虞文娟--典型城市群空间扩张及其对生态系统净初级生产力的影响.pdf(6389KB)学位论文--限制开放 联系获取全文

作者单位: 1.中国科学院生态环境研究中心
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[虞文娟]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[虞文娟]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2018  中国科学院生态环境研究中心 - Feedback
Powered by CSpace