Murray-Darling Basin floodplain inundation model. Version 2.0 (MDB-FIM2)

[摘要] This report describes the version 2.0 of the Murray-Darling Basin Floodplain Inundation Model (MDB-FIM2), released in July 2012. The MDB-FIM version 1.0 (MDB-FIM1) was developed to map spatial extent of floodplain inundation under ecologically significant flood return periods and to derive spatial inundation patterns over time across the Murray-Darling Basin (MDB) under different climate and development scenarios. MDB-FIM2 was built on the conceptualisation of its predecessor. Its development has been focused on advancing methodology and improving modelling accuracy. The major differences between the two versions are that MDB-FIM2 has:(1)updated input data to cover large flood events in 2010 and 2011(2)improved regionalisation by rectifying zoning, gauge locations and associated observed flow time series(3)modified and automated flood frequency analysis method(4)simplified the lag relationship between instream flows and consequent inundation of connected floodplains(5)verified model outputs at selected sites(6)automated the running of MDB-FIM and production of outputs using scientific workflow technology(7) applied a floodplain/wetland mask to the final products to minimise potential errors in inundation mapping. (8)Most importantly, the novel approaches in incorporating uncertainty into the method and results are step changes in the MDB-FIM2. The products of MDB-FIM2 have filled some gaps of inundation extent corresponding to annual recurrence intervals (ARIs) of ecologically significant flood events and scenarios which were not captured by the MDB-FIM1, especially those associated with ARIs greater than 1-in-5 and 1-in-10 years. The implementation of a different methdology for inundation mapping has led to differences in the products between the versions. Validation of the outputs of the revised product has not been extensive due to the resource and time constraints on the project; however the validation that has been undertaken shows a significant improvement in accuracy. Issues in the MDB-FIM2 as raised at the end of the report need to be addressed in the future generation of the model. In particular, the spatial and spectral limitations in MODIS inundation mapping must be understood when interpreting MDB-FIM2 products. It is proposed that future research focus on:(1)investigating the floodwater retention and inundation connectivity(2)developing a new method and associated metric that characterise the probability distribution of inundation across the Murray-Darling Basin (MDB), and capture the temporal dimensions of flow return periods(3)nesting the MDB-FIM with those from higher resolution modelling to retain whole-of-Basin coverage, and providing multiple levels of interpretation commensurate with scale(4)working with ecologists and hydrologists to match MDB-FIM’s spatial and temporal resolutions with that required by the ecological response models. MDB-FIM2 has the potential to provide a spatial framework for ecosystem response modelling across the MDB, which will link ecological responses to changes in river flows for modelling and monitoring required for a whole-of-MDB quantitative assessment of floodplain ecosystems and environmental assets. MDB-FIM is available under restricted use licence from CSIRO.

[发布日期] 2012-06-01 [发布机构] CSIRO

[学科分类] 地球科学(综合)