景观水文视角下的城市河流生态修复——以洛杉矶河复兴为例

Urban River Ecological Restoration from the Landscape Hydrology Perspective: A Case Study of the Los Angeles River Revitalization

河流生态系统退化问题近几十年来受到全球广泛关注,城市河流复兴运动自20世纪90年代起全面展开。河流生态修复离不开流域景观水文的恢复,引入功能流量概念恢复河流关键生态过程,是城市现实挑战下河流生态修复的最佳途径。针对中国河流修复中对河流生态系统整体结构和功能的研究和实践均很匮乏的现状,以几乎完全渠化的美国加利福尼亚州洛杉矶河为例,解析其过去20余年间3项主要复兴规划和研究成果,重点讨论与河流生态系统修复,尤其是水文恢复直接相关的规划与研究内容,包括河道防洪保障、区域生态系统构建、具体生态恢复策略以及远期生态流量研究等,并为中国(尤其是北方干旱地区)城市河流的生态修复工作提供有关规划尺度、技术支持及协调管理机制3方面的借鉴经验。

The deterioration of river ecosystems has attracted worldwide attention in recent decades, and the urban river revitalization campaign has been launched since the 1990s. Successful river ecological restoration is inseparable from the restoration of landscape hydrology at the watershed scale. Applying the concept of "functional flows" to restore the essential ecological processes may be the best option under the current challenging urban situations of China. In view of the lack of research and practice to restore the overall structure and function of river ecosystems in China, this study analyzed three planning and research projects of almost entirely channelized Los Angeles River in California, USA, during the past two decades. In this process, we focused on the stream ecosystem restoration, hydrological restoration in particular, including flood protection, establishment of regional ecosystem, specific ecological restoration measures, and long-term ecological flow study. We concluded with implications in following three aspects: the planning scale, technical support, and collaborative mechanism for urban river restoration in China, especially for the arid northern region.