Development of a catchment scale contaminant cycle model for stakeholder use - final project report.Report to River Contaminants Program of Land and Water Australia and Murray Darling Basin Commission

[摘要] The project contributes to the development of a comprehensive contaminant cycle model applicable to large catchments.The project elicited stakeholder input to the identification of priority contaminants and the spatial/temporal scales important to management, which informed model design.Four issues were identified:generation of contaminants (notably sediment, phosphorus and nitrogen); effectiveness of riparian buffers in trapping particulates (sediment and nutrient); effects of nutrients, flow and riparian shade on instream algal biomass and gross primary productivity; and effects of salinity on stream benthic macroinvertebrates.Five new computer models were developed that will be delivered through the modelling framework E2 (www.toolkit.net.au) - the riparian particulate (RPM), gross primary productivity (GPP), time-varying salinity effects (TVSE), algal biomass (ABM) and stream community metabolism (SCM) models.Due to E2 and stakeholder timelines, some activities are ongoing - RPM and GPP model sensitivity testing, and implementation of the TVSE, ABM and SCM models.The RPM, GPP and salinity tolerance models are currently being applied and tested in collaboration with stakeholders in south-east Queensland and the Wimmera, and this is building stakeholder ownership and trust.In addition to the computer modules, the project submitted six milestone reports, six technical reports, four journal articles and three conference papers.The project has identified two areas for future research.First, there is a clear need to better integrate field-scale experimental and modelling work with catchment-scale models in order to accurately quantify the effects of mitigation measures (e.g. grass buffer strips for trapping particulates and riparian soils for denitrification).This may require separate modelling of soluble and particulate forms of nutrient which are transported along different flow pathways and undergo different hillslope, riparian and instream transformations - current models lump different forms of nutrients and predict only totals.It may also require separate detailed field-scale, process models to inform the design of mitigation measures; and simpler catchment-scale models that capture the emergent properties of the field-scale models.Second, current models focus on predicting flow and contaminants while managers are often concerned with 'ecosystem health'.There is a clear need to more closely align measures of 'ecosystem health' with the capability of catchment-scale models.

[发布机构] CSIRO

[学科分类] 地球科学(综合)