1Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
2C-CIA-Climate Change Impacts and Risks in the Anthropocene, Institute for Environmental Sciences (ISE), University of Geneva, CH-1205 Geneva, Switzerland
3Institute of Earth Surface Dynamics (IDYST), University of Lausanne, UNIL Mouline, CH-1015 Lausanne, Switzerland
4Dendrolab.ch, Department of Earth Sciences, University of Geneva, Geneva, Switzerland
5Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Geneva, Switzerland
1Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
2C-CIA-Climate Change Impacts and Risks in the Anthropocene, Institute for Environmental Sciences (ISE), University of Geneva, CH-1205 Geneva, Switzerland
3Institute of Earth Surface Dynamics (IDYST), University of Lausanne, UNIL Mouline, CH-1015 Lausanne, Switzerland
4Dendrolab.ch, Department of Earth Sciences, University of Geneva, Geneva, Switzerland
5Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Geneva, Switzerland
Received: 22 Nov 2022 – Discussion started: 19 Jan 2023
Abstract. Different models have been used in science and practice to identify instream large wood (LW) sources and to estimate LW supply to rivers. This contribution reviews the existing models proposed in the last 35 years and compares two of the most recent GIS-based models by applying them to 40 catchments in Switzerland. Both models, which we call here empirical GIS approach (EGA) and Fuzzy-Logic GIS approach (FGA), consider landslides, debris flows, bank erosion, and mobilization of instream wood as recruitment processes and compute volumetric estimates of LW supply based on three different scenarios of process frequency and magnitude. Despite being developed following similar concepts and fed with similar input data, the results from the two models differ markedly. In general, estimated supply wood volumes were larger in each of the scenarios when computed with the FGA and lower with the EGA models. Landslides were the dominant process identified by the EGA, whereas bank erosion was the predominant process according to the FGA model. These differences are discussed and results compared to available observations coming from a unique database. Regardless of the limitations of these models, they proved extremely useful for hazard assessment, and the design of infrastructure and other management strategies.
Various models have been used in science and practice to estimate how much large wood (LW) can be supplied to rivers. This contribution reviews the existing models proposed in the last 35 years and compares two of the most recent spatially explicit models by applying them to 40 catchments in Switzerland. Differences in modelling results are discussed, and results compared to available observations coming from a unique database.
Various models have been used in science and practice to estimate how much large wood (LW) can...