Modelling wetland connectivity during overbank flooding in a tropical floodplain in north Queensland, Australia
Article first published online: 18 NOV 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Volume 26, Issue 18, pages 2710–2723, 30 August 2012
How to Cite
Karim, F., Kinsey-Henderson, A., Wallace, J., Arthington, A. H. and Pearson, R. G. (2012), Modelling wetland connectivity during overbank flooding in a tropical floodplain in north Queensland, Australia. Hydrol. Process., 26: 2710–2723. doi: 10.1002/hyp.8364
- Issue published online: 13 AUG 2012
- Article first published online: 18 NOV 2011
- Accepted manuscript online: 18 OCT 2011 09:48PM EST
- Manuscript Accepted: 12 OCT 2011
- Manuscript Received: 4 AUG 2010
- hydrological connectivity;
- hydrodynamic modelling;
- aquatic biota
Hydrological connectivity between floodplain wetlands and rivers is one of the principal driving mechanisms for the diversity, productivity and interactions of the major biota in river–floodplain systems. This article describes a method of quantifying flood-induced overbank connectivity using a hydrodynamic model (MIKE 21) to calculate the timing, the duration and the spatial extent of the connections between several floodplain wetlands and rivers in the Tully–Murray catchment, north Queensland, Australia. Areal photogrammetry and field surveyed stream cross data were used to reproduce floodplain topography and rivers in the model. Laser altimetry (LiDAR)–derived fine resolution elevation data, for the central floodplain, were added to the topography model to improve the resolution of key features including wetlands, flow pathways and natural and artificial flow barriers. The hydrodynamic model was calibrated using a combination of in-stream and floodplain gauge records. A range of off-stream wetlands including natural and artificial, small and large were investigated for their connectivity with two main rivers (Tully and Murray) flowing over the floodplain for flood events of 1-, 20- and 50-year recurrence intervals. The duration of the connection of individual wetlands varied from 1 to 12 days, depending on flood magnitude and location in the floodplain, with some wetlands only connected during large floods. All of the wetlands studied were connected to the Tully River for shorter periods than they were to the Murray River because of the higher bank heights and levees on the Tully River and wetland proximity to the Murray River. Other than hydrology, land relief, riverbank elevation and levee banks along the river were found key factors controlling the degree of connectivity. These variations in wetland connectivity could have important implications for aquatic biota that move between rivers and off-stream habitats during floods. Copyright © 2011 John Wiley & Sons, Ltd.