Testing and Application of the Riparian Particulate Model

Abstract

There is a pressing need for simple and easy to use models to enable assessment of the effectiveness of riparian buffers for pollutant trapping. The RPM was developed to address this knowledge gap for particulate trapping. The RPM captures important features of riparian buffer performance and enables investigation of the anticipated effects of changes to a range of buffer characteristics e.g. width, slope, vegetation type and placement. The RPM is applicable for use at hillslope or catchment scales. The testing of the RPM is a challenging task due to the difficulty in obtaining experimental data that is sufficiently well described to enable correct parameterisation of the model. The performance of the RPM was assessed here relative to two experimental studies. It was found that the RPM matched observed trapping efficiencies well when its parameter values were well known. Applications of the RPM at hillslope and catchment scales have also been demonstrated. The hillslope-scale application showed the potential for the model to simulate the likely effects on pollutant trapping of changes in common buffer characteristics. The catchment-scale application demonstrated the use of the RPM within a broader modelling context. It was possible, in the catchment-scale application, to compare the effectiveness of riparian buffer establishment against other potential pollutant control measures. Further development and testing of the RPM is required to improve confidence in model outputs. Those intending to use the RPM for management purposes should, where possible, implement monitoring programs to ensure correct parameterisation of the model. Further testing is needed at catchment scales. Testing of the performance of parts of the model that have not been thoroughly assessed, e.g. the reduction in trapping potential due to the damage of vegetation by high flows, is also needed.