DOI: 10.5194/hess-23-4349-2019
论文题名: Hydrodynamic simulation of the effects of stable in-channel large wood on the flood hydrographs of a low mountain range creek; Ore Mountains; Germany
作者: Rasche D. ; Reinhardt-Imjela C. ; Schulte A. ; Wenzel R.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2019
卷: 23, 期: 10 起始页码: 4349
结束页码: 4365
语种: 英语
Scopus关键词: Ecology
; Floods
; Hydraulic models
; Hydrodynamics
; Landforms
; Mesh generation
; Wood
; Habitat availability
; Hydraulic characteristic
; Hydrodynamic modelling
; Hydrodynamic simulation
; Roughness coefficient
; Spatio-temporal scale
; Two dimensional model
; Two-dimensional hydraulic model
; Rivers
; anthropogenic effect
; flood
; habitat availability
; hydrodynamics
; hydrograph
; simulation
; stream channel
; wood
; Erzgebirge Mountains
英文摘要: Large wood (LW) can alter the hydromorphological and hydraulic characteristics of rivers and streams and may act positively on a river's ecology by i.e. leading to increased habitat availability. On the contrary, floating as well as stable LW is a potential threat for anthropogenic goods and infrastructure during flood events. Concerning the contradiction of potential risks and positive ecological impacts, addressing the physical effects of stable large wood is highly important. Hydrodynamic models offer the possibility of investigating the hydraulic effects of anchored large wood. However, the work and time involved varies between approaches that incorporate large wood in hydrodynamic models. In this study, a two-dimensional hydraulic model is set up for a mountain creek to simulate the hydraulic effects of stable LW and to compare multiple methods of accounting for LW-induced roughness. LW is implemented by changing in-channel roughness coefficients and by adding topographic elements to the model; this is carried out in order to determine which method most accurately simulates observed hydrographs and to provide guidance for future hydrodynamic modelling of stable large wood with two-dimensional models. The study area comprises a 282 m long reach of the Ullersdorfer Teichbächel, a creek in the Ore Mountains (south-eastern Germany). Discharge time series from field experiments allow for a validation of the model outputs with field observations with and without stable LW. We iterate in-channel roughness coefficients to best fit the mean simulated and observed flood hydrographs with and without LW at the downstream reach outlet. As an alternative approach for modelling LW-induced effects, we use simplified discrete topographic elements representing individual LW elements in the channel. In general, the simulations reveal a high goodness of fit between the observed flood hydrographs and the model results without and with stable in-channel LW. The best fit of the simulation and mean observed hydrograph with in-channel LW can be obtained when increasing in-channel roughness coefficients throughout the reach instead of an increase at LW positions only. The best fit in terms of the hydrograph's general shape can be achieved by integrating discrete elements into the calculation mesh. The results illustrate that the mean observed hydrograph can be satisfactorily modelled using an adjustment of roughness coefficients. In conclusion, a time-consuming and work-intensive mesh manipulation is suitable for analysing the more detailed effects of stable LW on a small spatio-temporal scale where high precision is required. In contrast, the reach-wise adjustment of in-channel roughness coefficients seems to provide similarly accurate results on the reach scale and, thus, could be helpful for practical applications of model-based impact assessments of stable LW on flood hydrographs of small streams and rivers. © 2019 Institute of Electrical and Electronics Engineers Inc.. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162876
Appears in Collections: 气候变化与战略
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作者单位: Rasche, D., Freie Universität Berlin, Department of Earth Sciences, Institute of Geographical Sciences, Berlin, 12249, Germany, GFZ German Research Centre for Geosciences, Section Hydrology, Potsdam, 14473, Germany; Reinhardt-Imjela, C., Freie Universität Berlin, Department of Earth Sciences, Institute of Geographical Sciences, Berlin, 12249, Germany; Schulte, A., Freie Universität Berlin, Department of Earth Sciences, Institute of Geographical Sciences, Berlin, 12249, Germany; Wenzel, R., Freie Universität Berlin, Department of Earth Sciences, Institute of Geographical Sciences, Berlin, 12249, Germany, LfU State Office of the Environment Brandenburg, Potsdam, 14476, Germany
Recommended Citation:
Rasche D.,Reinhardt-Imjela C.,Schulte A.,et al. Hydrodynamic simulation of the effects of stable in-channel large wood on the flood hydrographs of a low mountain range creek; Ore Mountains; Germany[J]. Hydrology and Earth System Sciences,2019-01-01,23(10)