快速城市化进程中乌鲁木齐市景观格局时空分异特征的研究

发布时间：2018-09-17 20:37

【摘要】：城市化正对当今世界产生深刻的影响,中国的城市化已经进入加速发展时期。快速的城市化不仅表现在城市人口比例的提高,同时也带来城市景观格局、产业结构、城市用地和就业等的变迁。随着城市化的进一步发展,中国的城市生态面临着严峻的挑战。因此,城市景观受到越来越多的关注。城市景观格局是人地系统互动过程在地理空间中的真实反映,城市景观格局的时空变化反映了城市化的过程。研究城市景观格局的现状特征、演化规律及其形成机制,对于实现城市的可持续发展具有重要的理论和现实意义。本文以乌鲁木齐市为研究对象,首先利用ALOS/AVNIR-2、ALOS/PALSAR和数字高程图像ASTER GDEM,采用决策树方法提取了主要城市景观信息并对提取结果进行精度评价。由于收集的ALOS数据有限,无法进行城市景观空间变化的动态分析。因此,利用1990、1999和2010年的3期Landsat TM/ETM影像及数字高程图像(DEM)为数据源,综合利用RS、GIS技术与景观生态学的理论和研究方法,对乌鲁木齐市近20年间的景观格局变化及其各景观类型空间转化特征进行了分析。得到以下结论:(1)结合光谱遥感数据与微波遥感数据,可以补充光谱遥感数据中异物同谱问题所导致的城市建设用地与岩石裸地和山地阴影被误分为建设用地的缺陷,有效并更精确的提取城市建设用地信息,其总体分类精度达到了91.5%。(2)城市景观时空动态变化分析结果表明,1990-2010年乌鲁木齐市各景观类型面积比例的变化较明显,总体表现为建设用地大幅增加,土地利用动态度为16.87%,林地面积增加趋势,土地利用动态度达到了13.2%,其它植被和未利用地表现为持续减少趋势,每年减少1.23%和1.75%。在城市景观类型转移变化上,各景观类型的面积在空间分布上发生了一定程度的变化,主要是以建设用地面积的持续扩大,未利用地和其它植被面积的继续减少为特点。其建设用地的扩大,以其它植被和未利用地的转入为主,其中51.32 km2和150.85 km2面积转入建设用地。在地形条件的制约下,城市以“T”字形轴向式扩展显著,各景观类型发生转换的空间位置主要位于城市的西北和东北地区。在景观类型水平上,建设用地景观呈现优势度增强、边界越来越复杂和聚集度增长的趋势;其它植被优势度下降,破碎化程度增加;水体景观形状较为规则,破碎化程度降低;未利用地破碎化程度加强,优势度和聚集程度下降。在景观水平上,城市景观整体破碎化程度增加,形状趋于复杂,景观异质性增强,表现出多样化和均匀化的发展趋势。(3)绿地景观现状分析结果表明,整个研究区内的绿地类型以公园绿地和单位附属绿地为主,市区绿地景观多样性较低,各类型绿地景观所占比例不均匀,公共绿地数量少且趋于团聚分布,形成许多绿化服务盲区;各类型绿地景观分维数较高,形状较不规则;单位附属绿地和居住绿地的破碎度较高,因为它们受人类的影响较大,形状相对多样、不规则。(4)在城市景观类型动态变化的驱动力因素中,人口的增长、经济的快速发展、产业结构与政策等人文因素是引起景观类型变化的最主要的驱动因素,而地形因子对城市各景观类型空间结构演变过程的影响是不可忽略的,仍然在一定程度上限定城市空间结构的发展框架。
[Abstract]:Urbanization is having a profound impact on the world today. China's urbanization has entered a period of accelerated development. Rapid urbanization not only reflects the increase in the proportion of urban population, but also brings about changes in urban landscape pattern, industrial structure, urban land use and employment. Urban landscape pattern is the real reflection of the interaction between human and land systems in geographic space, and the temporal and spatial changes of urban landscape pattern reflect the process of urbanization. To study the present situation, evolution and formation mechanism of urban landscape pattern is very important for realizing the city. Sustainable development has important theoretical and practical significance.This paper takes Urumqi as the research object.First of all,using ALOS/AVNIR-2,ALOS/PALSAR and digital elevation image ASTER GDEM,the decision tree method is used to extract the main urban landscape information and evaluate the accuracy of the extracted results.Because the collected ALOS data is limited,it can not be carried out. Therefore, using Landsat TM/ETM images and DEM images of 1990, 1999 and 2010 as data sources, and using RS, GIS technology and landscape ecology theory and research methods, this paper advances the landscape pattern changes and the spatial transformation characteristics of landscape types in Urumqi in the past 20 years. The conclusions are as follows: (1) Combining the spectral remote sensing data and the microwave remote sensing data, it can supplement the defect that the urban construction land and the rock bare land and the mountain shadow are misclassified as the construction land, and extract the urban construction land information more effectively and accurately, and its overall classification accuracy can be improved. (2) The results of spatial and temporal changes of urban landscape showed that the proportion of different landscape types in Urumqi changed obviously from 1990 to 2010. The overall performance was that construction land increased significantly, land use dynamic degree was 16.87%, forest land area increased, land use dynamic degree reached 13.2%, other vegetation and unused land. In the change of urban landscape type transfer, the area of each landscape type has changed to a certain extent, mainly characterized by the continuous expansion of construction land area, unused land and other vegetation areas continue to reduce. It mainly transfers vegetation and unused land, of which 51.32 km2 and 150.85 km2 are transfered to construction land. Under the restriction of topographic conditions, the city expands remarkably in the form of "T" axis, and the spatial position of the transformation of landscape types is mainly located in the northwest and northeast of the city. The dominance degree strengthens, the boundary becomes more and more complex and the aggregation degree increases; the dominance degree of other vegetation decreases, the fragmentation degree increases; the water landscape shape is more regular, the fragmentation degree decreases; the unused land fragmentation degree strengthens, the dominance degree and the aggregation degree decreases. The results show that the green space types in the study area are mainly park green space and unit attached green space, the diversity of urban green space landscape is low, the proportion of different types of green space landscape is uneven, the number of public green space is small and the number of public green space is small. The fractal dimension of each type of green space landscape is higher and the shape is irregular; the fragmentation degree of the unit attached green space and residential green space is higher, because they are influenced by human being, the shape is relatively diverse and irregular. (4) In the driving force of the dynamic change of urban landscape types, the population growth. Rapid economic development, industrial structure and policy and other human factors are the most important driving factors for the change of landscape types. The influence of topography factors on the evolution process of urban landscape spatial structure can not be ignored, but still limits the development framework of urban spatial structure to a certain extent.
【学位授予单位】：新疆师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU984.1

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