Classifying landform at broad spatial scales: the distribution and conservation of wetlands in New South Wales, Australia

Abstract

Relatively few large-scale inventories of the world's wetlands exist because of the difficulties of spatial scale, associated cost and multiple objectives, often temporally confounded, that drive classification. The extent of wetlands across a large part of Australia (New South Wales, 80.6 million ha) was determined using satellite image analyses. These data allowed analyses of the distribution of wetlands, their conservation status and potential threats at different spatial scales; that is, State, coastal and inland, and catchment. Approximately 5.6% of New South Wales is wetland (4.5 million ha), mostly (96%) in inland river catchments. Broad classification allowed identification of the extent of wetland types: (i) floodplains (89%); (ii) freshwater lakes (6.6%); (iii) saline lakes (< 1%); (iv) estuarine wetlands (2.5%); and (v) coastal lagoons and lakes (1.5%). Conservation reserves protect only 3% of wetland area. The analyses identified the north-west as the key area for wetland conservation as most other catchments have lower wetland extent and more potential threatening processes. The first stage of a large-scale inventory is to determine the extent and location of wetlands, with immediate benefits for strategic conservation and management. Other objectives (e.g. classification, biotic composition, hydrology and threats) seldom have sufficient data available for large-scale inventories but can be completed later with resources.

Australia's Murray - Darling Basin: freshwater ecosystem conservation options in an era of climate change

“…With increasing concern over the state of the river and its wetlands, there are major questions about the sustainability of irrigation and the environment (Connell 2007). The MDB has high ecological values, with diverse species and ecosystems, nearly 5.7 million hectares of wetlands (Kingsford et al 2004a), and 16 wetlands listed as internationally important under the Ramsar Convention on Wetlands ( Fig. 1; DEWHA 2009).…”

Modeling 25 years of spatio-temporal surface water and inundation dynamics on large river basin scale using time series of Earth observation data

“…The majority of wetlands are floodplains, which cover around 6 % of the MDB's total area (Kingsford et al, 2004). In the second half of the 20th century, the MDB's water resources have been developed intensively with agriculture now taking up around 80 % of the MDB's area (CSIRO, 2008) and accounting for more than 80 % of the MDB's average annual surface water use of 11.3 km 3 year −1 (Leblanc et al, 2012).…”

“…Furthermore, the SWE dynamics of floodplain lakes differ greatly from those of shallow floodplains, especially with respect to the retention of flood water after a flood has passed. Therefore, we used an existing static wetland layer (Kingsford et al, 2004) to categorize the entire study area into floodplain, floodplain-lake, and nonfloodplain areas, so that the heterogeneous dynamics of SWE on these different entities could be accounted for in the modeling process (Fig. 2b, c).…”

Freshwater Ecosystem Conservation: Principles versus policy

“…The high-rainfall mountain districts in the east account for 5 per cent of the area and yet contribute more than 50 per cent of the run-off (CSIRO 2008). The MDB has diverse species and ecosystems, nearly 57 000 sq km of wetlands, and 16 wetlands covering 6363 sq km listed as internationally important under Ramsar (DEWHA 2009;Kingsford et al 2004;MDBA 2010aMDBA , 2010b. By distinguishing between 60 000 sq km of floodplains and 25 000 sq km of 'wetlands', the Murray-Darling Basin Authority (MDBA 2010a:59) does not appear to understand the broad definition of a wetland under the Ramsar Convention.…”