城市林木树冠覆盖研究进展

随着城市化进程的加快以及人们对由此产生的大量环境问题认识的不断加深,城市森林受到了越来越多的关注,它被越来越多的普通市民和科学家看做是有效解决城市环境与生态问题的最根本途径.在城市森林的维护、规划与建设过程中,城市林木树冠覆盖被认为是城市森林最重要的结构与功能衡量指标.针对我国城市森林研究与实践起步较晚的现实需求,从城市林木树冠覆盖的概念、分类与评价、城市林木树冠覆盖与城市森林服务功能、城市林木树冠覆盖的研究方法和城市林木树冠覆盖率与城市森林规划等4个方面,对国内外城市林木树冠覆盖研究的现状进行了评述.指出了该方面研究的未来趋势包括4个方面,首先,城市林木树冠覆盖研究,已经与城市的生态建设和日常生态、生产管理紧密结合.其次,高分辨率(米级以下)卫星影像在城市森林树冠调查与制图过程中的应用越来越普遍.第三,像面向对象的影像解译方法与激光雷达(LIDAR)等新技术将会得到更广泛的使用.第四,为了最终实现城市森林建设规划能够落地的目标,在城市森林建设的规划实施决策过程中,计算机辅助人工智能的应用将会普及.

The status and trend on the urban tree canopy research

Urban tree and forest establishment is becoming one of the most significant approaches for combating the ecological and environmental problems associated with the rapid urbanization globally. The fragmentation of urban landscape and built-in facilities may leave less large scale open spaces for developing patchy forests and green spaces. Therefore, the urban tree canopy is one of the best indictors for quantitively and qualitively assessing urban forest characteristics thus a primary measure for urban forest planning and management. As a result, many communities are adopting Urban tree canopy (UTC) goals to maintain and improve forest benefits. UTC is defined as precentage of the leaves, branches and stems of trees that cover the ground when viewed from above. It is therefore widely used for evaluating water quality improvement, energy saving, urban heat island mitigation, air pollution reduction, property values adding, wildlife habitat conservation, social and educational opportunities, and aesthetic benefits that urban tree and forest can provide. UTC is relatively easy to measure by remote sensing technology and less costly than field sampling. UTC is a comparable index across a city and among cities whatever the size of the area is measured. In addition, UTC is a good performance measure for detecting changes across space and time and an easy-to-understand concept for communicating between managers and the public. The present development of UTC studies and applications can be summarized as 1) the UTC researches have firmly related with the eco-construction,people's living and city management, 2) the high resolution images are broadly utilizated in UTC investigation and maping, 3) the Object-Based Image Analysis method and LIDAR technology are being applicated in the UTC research, and 4) the assistant artificial intelligence decision-making system will be popularized in the UTC construction and management.