城市景观格局与环境因子的耦合及优化研究

Global urbanization has been accelerating since 1990s. In China, the urbanization level increased to over 52% in 2014.Along with economic growth and urban population explosion, human’s disturbance on natural landscape is unprecedented,threatening national policy goals environmental conservation. Like the concept of “compact city” from western world, the core of intensive urban land use is to bare more city elements in smaller areas. However, with urban land more and more compacted, environmental problems，expecially air pollutions are becoming still further tangible. The contradiction between the idea of compact city and accompanied environment problems forms "compact city paradox". The earlier studies on this issue was lack of spatial idea and always in macro-level, seldom considering the heterogeneity of environmental factors in complex urban landscape. Taking Nanchang city as a case, this study firstly studies the air pollution characteristics and its interaction with meteorological factors. Then,the spatial distribution and influence degrees of the air pollution factors are determined based on multiple sampling points monitoring. Urban landscape are classified as function zones according to major land use types and their sensitivity to air pollution factors are decided based on intensive use level. From coupling pattern and process of landscape ecology perspective, the spatial model of "air environment quality = influence degree + sensitivity" is established. The spatial model of air environment quality is put forwards. Finally,scenarios are applied to study the possible solutions to "compact city paradox" by means of landscape planning and pattern optimization . This study will not only enrich the theory of air environment effects on urban landscape, but also offer the possible options to environment problems in "compact city" of China since it is estimated that increment of urbanization level will over 1.5%/year until it reaches 70%, thus compact city and accompanied environment problems will be a long- time puzzle.

如何控制城市过快扩张，集约（紧凑）利用土地资源近年来成为一个研究热点。相关研究表明，随着城市土地利用“紧凑化”，环境特别是大气环境问题会变得越来越突出。以往对这一问题的研究较为宏观，较少考虑更微观尺度上大气环境因子与城市景观的空间异质性。本研究以南昌市城市景观为研究对象，首先从宏观层面研究大气污染特征及其与气象因子的关联性。其次通过布置多个监测点监测大气环境，研究主要大气环境因子的空间分布与影响程度；基于景观现状，按主导地类一致原则将城市景观划分为居住、商业等功能区，进行集约利用水平程度分析，研究景观对大气环境因子的敏感度。从耦合格局与过程的景观生态学视角，综合考虑影响程度和景观敏感度，构建“大气环境质量=影响程度+敏感度”的空间耦合模型。最后，基于景观规划理论与耦合模型，探讨通过景观功能区调整与格局优化缓解大气污染的可行性。研究成果将为紧凑城市环境问题的解决提供理论基础和可操作模式。

自1990年以来，全球城市化进程日益加速。我国在2014年城市化率已经达到了52%，人们对自然景观的干扰是空前的，如何控制城市过快扩张，集约（紧凑）利用土地资源近年来成为一个研究热点。相关研究表明，随着城市土地利用“紧凑化”，环境特别是大气环境问题会变得越来越突出。以往对这一问题的研究一般集中在气象科学领域，较少考虑更微观尺度上大气环境因子与城市景观的空间异质性。本研究以南昌市中心城区景观为研究对象，通过调研与采集中心城区9个国控大气质量监测点数据，采用土地利用回归（LUR）方法高精度模拟6类主要污染物（PM2.5，PM10，SO2， NO，CO，O3）空间分布；其次从土地利用功能的角度，基于景观现状，按主导地类一致原则将城市景观划分为居住、商业、教育、工业等功能区，通过二者耦合研究，揭示了土地利用对主要大气污染物的影响与表现形式；其次，从更微观的角度，研究不同土地用功能区的集约利用水平对主要大气污染物分布的影响，揭示了影响机制。最后，以城市绿地景观为主要类型，探讨了不同城市绿地景观特征对大气污染物分布的影响及其作用距离范围。研究成果不但丰富了景观变化大气环境效应研究相关理论，也为紧凑城市大气环境问题的解决提供理论基础和可操作模式。