基于长时间序列遥感影像的城市景观格局动态度研究

Urban landscapes are highly dynamic. Accurate information of urban landscape and its change is crucial for developing an ecological understanding of urban landscape. Although mapping and change analysis of urban landscape have been widely carried out based on every 5 or 10 years’ interval, detailed information on when changes occurred and frequency of change on urban landscape are largely missing. Here, we present a new approach which integrates change detection technique of remote sensing and analysis method of landscape dynamics by using time series of Landsat TM/ETM+/OLI imagery. We choose four cities, Beijing and Shenzhen in China, Baltimore and Phoenix in the United States, as study areas and investigate the accurate information on changes, including the time when changes occurred and the frequency of change. We will then comparatively analyze the spatiotemporal pattern and differences of urban landscape dynamics, considering the time when changes occurred and the frequency of change, along the urban-rural gradient, and in the expansive and build-up areas during 1986-2017. We try to explore the general rule of urban landscape dynamics based on the comparisons of cities with different size and growth speed. The results from this study will help us better understand the landscape dynamic characteristic of urban area and provide useful information for urban ecological and environmental effects of urban landscapes.

城市生态环境问题的产生，都直接或间接地与城市景观格局的动态变化密切相关。定量刻画城市景观格局的特征与动态变化，是解决各类生态环境问题的基础与前提。城市景观具有时间上高度动态的特征，如何准确地界定城市景观格局变化的时间，以及在某一给定时间范围内的变化频率，是城市景观格局动态研究中的难点，缺乏相应的分析方法和技术。本研究拟在整合多种遥感影像分析技术和景观动态分析方法的基础上，首先构建一种基于高密度、长时间序列遥感影像的城市景观动态变化分析新方法，准确地识别城市景观格局变化的时间与变化频率；进而以中国与美国的四个典型城市——北京、深圳、巴尔的摩和凤凰城为研究区域，应用构建的新方法，开展城市景观格局动态的精细解析与对比分析，并探索一般性规律。本研究有助于深化城市景观格局与动态的科学认识，并可为城市景观动态变化的生态环境效应研究提供新的思路和方法。