区域视角下棕地群的遥感信息提取、特征识别与生态效益评价

The challenge of brownfield regeneration in China has become a critical issue. A large number of heavy-contaminated factories and mining sites are closed. Cities are surrounded by landfills and illegal dumps. It has become a common phenomenon that clusters of brownfields exist at regional scales. Constrained by the ground condition and limited timetable, many brownfields are transformed into green open spaces, becoming an important component of urban green system. Within landscape architecture research worldwide, brownfield regeneration has already been a hot pioneer subject. However, brownfields in China today are generally redeveloped case by case, lacking comprehensive planning at the regional level. Thus, a great opportunity to develop urban green systems using the transformation process of brownfields is missed. This research chose two typical regional brownfield clusters as the research subject, one is the IBA Emscher Park in the Ruhr District in Germany, and the other is the Dou River industrial band in Tangshan, China. Using the satellite remote sensing images of each region at three different time-phases, information is extracted through a combination of automatic and manual methods. Characteristics of brownfield clusters will be analyzed at a regional scale, both in spatial pattern and in the transformation process. Thermal infrared analysis will be adopted to evaluate the ecological performance of the sites after transformation into green open space by factors of green volume, thermal environment, and micro-climate around large-scale brownfield regeneration landscape projects. Finally, landscape information modeling will be used to simulate alternative regional transformation scenarios and predict its ecological impact, providing a technical roadmap and assisting the comprehensive decision-making process of the transformation of brownfield clusters at the regional scale.

中国棕地问题严峻，重污染企业搬迁、大量矿业企业关停、垃圾围城，数量众多的棕地以棕地群的形式在区域范围内存在已成为普遍现象。受地基条件与项目周期的制约，相当一部分棕地被改造为绿色开放空间，成为城市绿地系统的重要组成部分。棕地再生成为国内外风景园林学研究的前沿热点课题。然而，我国目前的棕地改造模式基本为“就地论地”，缺乏区域视角下的综合统筹，丧失了将棕地改造作为合理化调整并发展城市绿地系统的契机。本研究选取德国IBA埃姆舍园区与中国唐山沿陡河工业带两个典型棕地群区域，通过对不同时相的遥感卫星影像进行信息提取，运用自动解译与人工解译相结合的方法，在区域视角下对棕地群的空间分布特征与改造演进特征进行识别，并通过热红外分析对改造后的绿量、热环境与大型绿地周边微气候等进行量化的生态效益评价。进而运用景观信息模型技术，对多种改造情景进行模拟与预测，为区域视角下棕地群改造的综合统筹提供技术路线与决策依据。

棕地已成为我国城市化进程面临的严峻挑战，以绿地为改造用途的棕地再生是风景园林学科的重要前沿研究领域之一；目前学科内研究以综述型或介绍型成果居多，侧重于具体设计案例与最终形态，尚缺乏对区域棕地群改造演进发展过程的特征描述与量化研究，及在区域视角下对棕地群再开发的系统探讨。. 本研究提出棕地群的重要概念，针对改造前、改造完成时、改造后三个时相，将德国IBA埃姆舍园区与中国唐山市沿陡河工业带两个典型棕地群区域作为研究对象，构建了基于遥感信息提取的识别方法、目视解译规则及特征知识库，结合实地调研情况，完成两地不同改造阶段的棕地群空间分布特征识别；并通过不同时相的遥感卫星影像反演，完成改造前后的绿量与热环境因子的计算，结合大型棕地再生项目及其周边区域的因子变化特征，进行量化的生态效益评价。. 研究构建了工业废弃地、采矿废弃地、基础设施废弃地、垃圾填埋场及疑似棕地5类棕地场地的遥感影像特征知识库，并归纳出8项目视解译规则；在两处重点研究区域内，采矿废弃地单体面积最大，工业废弃地总面积最大且单体场地面积较小；四类棕地在地块形状上没有显著区别特征；唐山沿陡河工业带与德国埃姆舍园区棕地群变化具有差异性，但空间分布上均与河道关系紧密；越靠近再生后的棕地，降温效应越明显，地块内外温度变化均呈现了逐年整体化的趋势；再生后棕地范围内绿量的变化特征与棕地再生类型关系密切。. 本项目为棕地再生研究提供了棕地群的重要区域视角，从完成棕地的遥感影像特征识别、棕地群空间制图、量化分析、效益评价等角度建立了工作流程与内容框架，旨在为我国其他城市棕地群景观更新研究、地景规划与生态修复、资源衰退型城市棕地再生等研究提供有益借鉴，并为从区域视角推动棕地再生进程提供重要的理论支撑。