Mapping and Spatio-Temporal Analysis of Flooded and Inundated Areas in the Lower Balonne Floodplain, Queensland, Australia

摘要

Water storage infrastructure developments and other land use changes may impact the extent of water flows and inundation in the floodplain. This may bring negative environmental effects and conflicts between competing users of water. In a case study of the Lower Balonne floodplain in Queensland, Australia, this project was conducted to quantify the changes on the spatial extent and patterns of flooded and inundated areas in a large, ephemeral floodplain river system. The study employed digital image processing techniques to produce inundation maps from the 1994 and 2004 flood events captured by Landsat 5 imagery. Using a landscape patterns analysis program (Patch Analyst) linked with a geographic information system (GIS), selected landscape metrics pertaining to patch size, shape, and connectivity were calculated and analysed. The results show not only the significant reduction (44,658 ha corresponding to 43% decrease) in the extent of the flooded and inundated areas, but also the changes on the spatial configuration of these patches. They became more fragmented and isolated, particularly in the lower region of the floodplain. This study concluded that the use of landscape metrics could be valuable for floodplain monitoring.