Engineered Large Wood Structures in Stream Restoration Projects in Switzerland: Practice-Based Experiences

Water

卷:13

Matthias Mende¹  Vasco Neuhaus² 

[1] IUB Engineering AG, 3014 Bern, Switzerland;

[2] IUB Engineering AG, 8004 Zürich, Switzerland;

关键词: large wood;    key log;    log jam;    anchoring;    river restoration;    practice-based experiences;   

DOI  :  10.3390/w13182520

来源: DOAJ

【 摘 要 】

The effects of large wood (LW) presence in streams on river ecology and morphology are becoming widely researched and nowadays their ecological benefits are undisputed. Yet LW presence in most Swiss plateau streams is poor mainly due to anthropological pressure on river ecosystems. The use of anchored, engineered LW structures under various forms in stream restoration projects is now state of the art. However, binding benchmarks for the equivalent naturally occurring instream LW quantities and complex LW structures do not yet exist. Therefore, hydraulic engineers often find themselves in a conflict between acceptable instream LW quantities for flood protection, quantities desirable from an ecological point of view and, last but not least, quantities accepted by the public based on the current ideologies of landscape design. In the first section, this paper treats the complexity of defining benchmarks for LW quantities in restoration projects. In the second section, we provide a qualitative practical insight into relevant questions when planning engineered LW structures, such as placement, anchoring, naturalness, and effectiveness from a hydraulic engineer’s point of view. The third part presents three examples of restoration projects with different dimensions where various engineered LW structures with different outcomes were built and introduced into active streams. Finally, the conclusion provides further possible measures to retain LW in streams and to restore more natural LW dynamics in rivers.

【 授权许可】

Unknown