基于城市河流半自然化的生态防洪对策——河滨缓冲带与柔性堤岸设计导引

DESIGN GUIDE OF RIPARIAN BUFFERS AND SOFT BANKS DESIGN

旨在将城市河流半自然化与生态防洪对策落实到城市设计层面。根据观测水位、防洪、防潮标准确定缓冲带鼓励淹没范围、堤顶控制点标高,结合亲水性活动、适宜土地利用方式及景观要素,给出8种典型缓冲带断面设计及相应护岸生态工法。设计导引以海河下游为例,采用绩效控制、示例设计方法,主要内容包括目标-策略表、控制要点与编制方法表、示例设计图、应用索引图等。导引有助于消除防洪设施带来的视线遮挡、增强河滨缓冲带土地利用复合性与公共性,缓解防洪与亲水性、城市区生态用地与河滨土地稀缺性等矛盾,以保持河滨持久性活力。

Spatial strategies for sustainable flood control in conjunction with architectural flood proofing measures are incorporated into the conventional riverfront urban design guide. Synthesizing hydrological and ecological concerns, a performance-based, quasi-quantitative approach that aims to revitalize degraded urban rivers in the long run, is delineated through a case along lower reaches of River Hai. The guide uses charts and tables together with scaled sketches including a chart of objectives and strategies for urban river repair, a table of determination of control elements with respect to flood control, ecological enhancement and water sensitive land-uses, representative cross-sectional design for riparian buffers and soft-banks, sample design for eco-engineered revetments, and an index map showing each type ofbuffers applied in the studied area. Application resuits reveal that the guide can serve as a template for balancing the stress between flood protection and human-water connection as well as reducing the conflicts between the riverfront land scarcity and required ecological land.