【作者】 谷康；

【导师】 季孔庶；

【作者基本信息】 南京林业大学 ， 园林植物与观赏园艺， 2020， 博士

【摘要】 进入21世纪以来,生态文明建设与美丽中国建设已成为城市发展的重要内容,扬州市城市生态环境建设近年来取得了令人瞩目的成就,2010年,扬州成为全国首批申报国家生态园林城市,这与扬州得天独厚的自然条件、合理的城市规划和各级政府积极推进城市绿地建设是密不可分的。十八大以来,中国政府对生态文明建设提到了前所未有的高度,大力推进生态文明建设成为实现十九大提出的全面建成小康社会这一宏伟目标的生态保障。本文从城市绿地空间格局的结构与功能方面入手,利用调查数据分析近二十年来扬州市中心城区绿地空间格局发展变化,探究城市绿地建设与城市空间发展及人口分布等的关系,为优化扬州城市绿地空间格局,改善城市绿地的综合服务水平,提升城市生态效益及社会效益提供技术支持。本文以扬州市中心城区绿地为研究对象,以景观生态学为理论基础,从连接度、渗透度和密度三个方面构建城市绿地空间格局评价体系;借助于Arc GIS、Fragstats等技术手段,对扬州市近二十年来的城市绿地进行分析,分析中心城区绿地网络基本构建的连接情况、辐射区的渗透情况、评价绿地网络影响区的密度情况,在此基础上,提出扬州市中心城区绿地空间格局优化思路,为扬州城市生态建设献计献策。首先,搭建绿地空间格局与生态网络的关联构架。本文在介绍城市绿地发展和研究趋势的基础之上,对绿地空间网络格局进行界定,并且从绿地网络化空间系统层面提炼出三个评价指标,包括用以评价绿地网络基本构架的连接度、评价绿地网络辐射区的渗透度以及评价绿地网络影响区的密度,致力于解决城市绿地空间格局的三个关键问题,即绿地空间结构的连接情况,区域斑块的渗透能力以及绿地斑块的布局模式。以提升城市绿地分布的合理性与均衡性,从而最大化发挥城市绿地的综合效应,此为本文对扬州市中心城区绿地空间格局优化进行研究的理论基础。其次,建构了城市绿地空间格局评价体系。论文以连接度、渗透度与密度为三个主要的评价指标,运用多种景观指数建立了对空间格局的评价体系,以及以功能模型为基础的可达性分析,提取抽象绿地空间格局特征并反映城市绿地服务功能发挥的能力,以此作为能够更为科学地为城市绿地建设提供建议与指导的理论依据。这是本文对绿地格局进行研究的关键组分。第三,对绿地空间格局现状进行定量分析。本文借助于Arc GIS、Fragstats等技术手段,分别提取扬州市2001年、2014年和2018年的城市中心城区绿地空间信息,并从连接度、渗透度和密度指数方面进行分析对比,总结扬州中心区绿地空间格局近二十年来的变化趋势。首先针对扬州市中心城区9种土地利用类型,绘制2001年,2014年和2018年中心城区土地利用类型图。笔者发现,在2001年,邗江区绿化效果相对较好,绿地斑块面积最大,约882.373km~2,数量也最大,约527块;绿地格局具有相对优势。公园绿地生态基础最好,主要分布在北部蜀冈-瘦西湖片区,公园绿地平均斑块面积约为255.256km~2,公园绿地的连通性相比之下高于其他绿地类型,斑块密度高,绿地可达性较好,连通性指标达91.1208,服务能力好,斑块丰富度最高,约为0.0885。维扬区的连通度指标在三个区中最低,为57.1429,绿地斑块多被道路分割,边缘形状较为不自然,维扬区面积不大,故此区域内斑块密度及均匀度相对较高,但由于人口密度较大,斑块均匀度指数最低,约0.3309,导致绿地可达性一般,部分东部区域可达性极差。维扬区绿地整体绿地数量少、面积小,斑块面积约279.4127km~2,数量约122块。布局分散,连接度水平不佳,优势绿地类型不突出,绿地斑块较为破碎,密度较低,公园绿地的斑块均匀度指数只有0.0274,斑块边缘形式单调,绿地空间格局的优势度与均匀度低。2011年扬州市增设江都区,中心城区的绿地空间格局有了新的变化。到2014年,邗江区的景观面积值最高,为2405km~2、斑块数量值也最高,为559。邗江区仍存在着绿地斑块之间连通性差,景观与城市其他要素的渗透性不强的问题。公园绿地的连通性指标最高,达89.8769。邗江区绿地边界不规则程度高,与其他区域相比具备较好的渗透能力。邗江区绿地的边界长度总和TE值属公园绿地和区域绿地最大,分别为154953和11396。邗江区内大部分绿地斑块密度大于10,边缘密度大于3,说明中心城区内绿地斑块边缘形状较为不自然且较为聚集,但是不能良好的发挥绿地的边际效应,影响绿地影响效应的发挥。广陵区的绿地斑块多分布于老城区和水域周围,绿地分布较为破碎,斑块边缘形状不自然,边缘效应不佳,绿地连通性较差,公园绿地的连通度指标为89.8176。但此区域斑块密度高,依托道路、水系建设的防护绿地边缘较为自然,表现较好,公园绿地的斑块丰富度为15.4761。至2018年,扬州市中心城区绿地格局变化较2014年不大,扬州市公园绿地可达性仍然需要继续进一步改善,5min内能到达绿地的区域占33%,5-15min可到达绿地的区域占比28%,15-30min可到达绿地的区域占比占比19%,就公园绿地的分布来看,中、西部城区公园的服务覆盖面积较广,服务能力较好,南、东部片区的公园绿地可达性低。分析结果表明,扬州中心城区绿地网络格局呈现“廊道-斑块-基质”的结构模式,总体发展较为良好,然而针对部分不足之处需要相关布局与管控策略加以提升优化。分析结果中,邗江区绿地优势较为明显,绿地类型、数量、密度与可达性等多项指标排名靠前;广陵区整体绿地质量居其次,存在破碎化、不均衡、渗透性不佳与边缘人为干扰严重等问题;开发区整体绿地水平较为普通;江都区绿地建设资源较好,但斑块分布存在南北不均的问题,需要结构层面的提升与优化。这是本文对扬州市中心城区绿地空间格局优化进行研究的数据基础。最后,论文基于前期分析提出一套基于网络结构的城市绿地空间格局优化策略。优化策略以构建绿地网络化布局为总体思路,从空间技术与管理实施两个层面制定与展开。空间技术层面策略由连接度、渗透度和密度三个方面组成。连接度方面,确定连通性偏离正常范围的区域,对连接度高的地方进行资源保护,对连接度低甚至无连接度的区域通过建立生态溪沟、廊道、屋顶花园、踏脚石等措施,增加绿地空间的连续性;渗透度方面,明确边缘形状较为规则、向周边地域渗透效果差的绿地斑块,并且对这些生态效益较差的斑块进行空间格局优化,以实现景观镶嵌与功能渗透;密度方面,为使城市绿地结构与功能的综合效应得到有效发挥,对存在绿地可达性欠缺、分布不均的区域加以确认并提出适宜性廊道、均衡性网络与补充节点等结构性策略以及均衡可达和服务覆盖等功能性策略;管理实施层面上,保护空间格局良好的区域,积极规划与修复空间格局薄弱的区域。这是本文对扬州市中心城区绿地空间格局优化的方向。综上所述,本文以景观生态学为理论基础,通过运用相关的GIS应用技术、Fragstats格局分析技术手段,在综合分析扬州中心城区绿地空间格局近二十年发展变化的基础上,因地制宜地提出中心城区绿地空间格局优化的方向,为扬州城市生态环境良性发展提供技术支持,为扬州实现小康社会、健康中国的奋斗目标提供理性决策思路。更多还原

【Abstract】 The 21st century has witnessed that the ecological civilization and Beautiful China Initiative have become an important part of urban development.Yangzhou City has been blessed itself with remarkable achievements in the construction of urban ecological environment in recent years.It was enlisted in the first batch applying for National Ecological Garden City in 2010,which was closely related to its unique natural conditions,rational urban planning and the active promotion of urban green space construction by governments at all levels.Since the 18th National Congress of CPC,Chinese government has set unprecedented standards for ecological civilization to vigorously promote the development of ecological civilization in order to make the ecological guarantee for realizing the grand goal of building a well-off society in an all-round way put forward in the 19th National Congress of CPC.From the perspective of structure and function of urban green space,the thesis analyses the development of Yangzhou downtown green space in the past twenty years by means of research data and explores the relationship between urban green space,urban space development,population distribution,etc.It will technologically enhance the structure and overall services of green space,as well as ecological efficiency and social benefits of Yangzhou.Based on the theory of landscape ecology,the thesis takes urban green space in downtown of Yangzhou as the research object,and constructs an evaluation system for the spatial pattern of urban green space from three aspects:connectivity,permeability and density.With the help of Arc GIS,Fragstats and other technical means,the changes of urban green space in Yangzhou in the past 20 years is analyzed from the perspectives of the connectivity of the basic construction of the green space network in the central city,the permeability of the radiation area and the density evaluation in the affected area of the green space network.Based on this,the thesis comes up with strategies on how to upgrade the spatial pattern of the green space in downtown of Yangzhou,and thus assists its efforts for the urban ecological construction.Firstly,the correlation framework of green space pattern and ecological network is built.The concept of green space network pattern has been defined according to the development and research trends of urban green space,and three evaluation indexes have been summarized on the basis of green space network system,including the connectivity of evaluating the basic framework of green space network,the permeability of evaluating the network radiation area and the density of evaluating its affected area,which are used to solve the three key issues of the spatial pattern of urban green space,that is,the connectivity of green space network,the permeability of regional plaques and the layout pattern of green space patches,in order to improve the rationality and balance of urban green space distribution and maximize the comprehensive effect of urban green space.This is the theoretical basis for the thesis to study the optimization of spatial pattern of urban green space in downtown of Yangzhou.Secondly,the evaluation system of the spatial pattern of urban green space is built.Taking connectivity,permeability and density as three main evaluation indexes,the thesis establishes an evaluation system of spatial pattern by using various landscape indices,as well as through correlation analysis based on the functional model,extracts the characteristics of spatial pattern of abstract green space,and reflects the ability of service function of urban green space,which can be used as a theoretical basis for more scientific suggestions and guidance for urban green space construction.This is the key component of the study on green space pattern in the thesis.Thirdly,the present situation of the spatial pattern of green space is analyzed quantitatively.With the help of Arc GIS,Fragstats and other technical means,the thesis collects respectively the spatial information of green space in downtown of Yangzhou in 2001,2014 and 2018,and makes analysis and comparison from perspectives of the connectivity,permeability and density to conclude its green space evolution in past 20 years.Firstly,according to 9 kinds of land use types in the central urban area of Yangzhou City,the land use type maps of the central urban area in 2001,2014 and 2018 were drawn.The author found that in 2001,the greening effect of Hanjiang District was relatively good,the patch area of green space was the largest,about882.373km~2,and the number was the largest,about 527 pieces.The green space pattern had comparative advantages.The ecological basis of park green space is the best,mainly distributed in the northern Shugang-thin West Lake area.The average patch area of park green space is about 255.256km~2.The connectivity of park green space is higher than that of other green space types,the patch density is high,the green space accessibility is good,the connectivity index is91.1208,the service ability is also good,and the patch richness is the highest,about 0.0885.The connectivity index of Weiyang area is the lowest among the three areas,about 57.1429.Most of the green patches are divided by roads,the edge shape is not natural,and the area of Weiyang area is small,so the patch density and evenness in the area are relatively high.However,due to the large population density,the patch evenness index is the lowest,about 0.3309,resulting in the average accessibility of green space,while the accessibility of some eastern regions is extremely poor.In weiyang district,the total amount of green space is small and the area is small.The patch area is about 279.4127km~2and the number is about 122 pieces.The distribution is scattered,the connectivity level is not good,the dominant green space type is not prominent,the green space patches are fragmented,and the density is low.The patch evenness index of the park green space is only0.0274,the patch edge form is monotonous,and the dominance and evenness of the green space pattern are low.In 2011,jiangdu district was added in Yangzhou,and the spatial pattern of green space in the central city had new changes.In 2014,the Hanjiang river area had the highest landscape area value 2405km~2,and the highest patch quantity value 559.The Hanjiang river area still has the problem of poor connectivity between green patches and weak permeability,it also has the problem between landscape and other urban elements.The highest connectivity index was 89.8769.The green space boundary in Hanjiang area is irregular and has better permeability than other areas.The TE value of the total length of green space in Hanjiang area is the largest of park green space and production green space,154953 and 11396,respectively.The density of green patches in Hanjiang river area is more than 10,and the edge density is more than 3,indicating that the shape of green patches in the central urban area is not natural and more concentrated,but the marginal effect of green patches cannot be played well,which affects the effect of green patches.Greenbelt patches in guangling district are mostly distributed around the old town and water area,and the greenbelt distribution is fragmented.The patch edge shape is not natural,the edge effect is not good,and the greenbelt connectivity is poor.The connectivity index of park greenbelt is 89.8176.However,the patch density in this area is high,and the green space edge protected by road and water system construction is more natural,showing a better performance.The patch richness of green space in the park is second only to hanjiang district,with 15.4761.In 2018,the center of yangzhou city green space landscape change from 2014,Yangzhou city park green space accessibility is still need to continue to further improve,5 min can reach the green land area accounted for 33%,5-15 minutes to the green land area accounted for 28%,15 to 30 minutes to the green land area accounted for 19%,is the park green space distribution,service coverage area,western city park in broad,has good service ability,south,and east area of park green space accessibility is low.As it turns out,the downtown green space network of Yangzhou is characterized as"corridor-patch-matrix"structure pattern,and the overall development is relatively good.However,in view of some shortcomings,relevant layout and control strategies need to be improved and optimized.The research outcome states that among others,Hanjiang District is desirable in green space with top-notching indexes of varieties,number,density,accessibility,etc;Guangling District is secondary in green landscape afflicted by fragmentation,imbalance,impermeability and marginal human interference;Development District is comprehensively average;Jiangdu District enjoys resourceful green space,but its green blocks are not balanced in its south and north areas which are in need of structural improvement.This part involves the data foundation of downtown green space enhancement in Yangzhou.Finally,the optimization strategies of network-based urban green space are put forward after the preliminary analysis.Guided by the outlook of green space network construction,strategies are formulated and carried out from perspectives of space technology,and management and implementation.The spatial technique strategies consist of three aspects:connectivity,permeability and density.In terms of connectivity,areas deviated from the normal range are identified,resource protection is carried out in areas with high connectivity,and ecological gully,corridor,roof garden,stepping stones or so are built to increase the connectivity of green space in areas with low or no connection in between.In terms of permeability,green patches with relatively regular edges and poor ability to permeate into surroundings are identified,and the optimization of patches with poor ecological function is carried out to enable landscape mosaic and permeability.In terms of density,in order to give full play to the structural and functional role of urban green space,structural strategies like establishing corridors,networks enabling re-balancing and supplementary nodes,and functional strategies such as beefing up accessibility and expanding service coverage are applied to areas with poor accessibility and uneven green space distribution.In terms of management and implementation,protection is still needed in areas with good green spatial pattern,while sound plans and restoration efforts are required in areas with weak spatial pattern.This part constitutes the direction of optimizing the spatial pattern of green space in downtown of Yangzhou.In summary,based on the theory of landscape ecology and relevant techniques such as GIS and Fragstats,the thesis,after analyzing the changes of Yangzhou downtown green space in the past twenty years,puts forward strategies to optimize and improve Yangzhou downtown green space accordingly as well as provides technical support to facilitate ecological conservation and environmental protection of Yangzhou,so as to provides rational decision-making for Yangzhou when it is striving to build a well-off society and a beautiful city.更多还原