ROTAN is a GIS-based catchment hydrology and water quality model that models the effects of land-use change and nitrogen mitigation measures such as riparian margins and plant uptake on nitrogen export to waterways. This model is based on the Scandanavian HBV and HBV-N models in which soils and aquifers are modelled as a series of fully-mixed reservoirs (buckets) connected in series and parallel. ROTAN has been developed by NIWA and has been used in policy formulation related to the Lake Rotorua catchment.
ROTAN is used for the prediction of nitrate inputs to lakes for various land use, rainfall, and mitigation scenarios.
| State of Development | Closed Beta |
|---|---|
| Current Development Activity | Nil |
| Outcome Areas | Environmental |
|---|---|
| Management Domains | Freshwater |
| Intended End Users |
|
| Spatial Resolutions | 500-1000m |
| Spatial Extents | Local (i.e. Catchment or District) |
| Spatial Dimensions | 3D |
| Temporal Resolutions | Days, Months |
| Temporal Extents | Days, Months |
| Steady State or Dynamic | Dynamic |
| Level of Integration | Environmental |
| Key Input Data | Land Use, Rainfall, Land Cover, Potential Evaporation |
|---|---|
| Input Data Formats | GIS compatible files |
| Key Output Data | Runoff, Drainage water flows and nitrogen concentrations |
| Output Data Formats | GIS Compatible Files |
| Open/Closed Source | Closed Source |
|---|---|
| Licence Type | Unknown |
| Licence Cost (Non Commercial) |
Not available for non-commercial use |
| Licence Cost (Commercial) |
Not available for commercial use |
| Operating Systems | MS Windows ArcGIS |
|---|---|
| Software Needed | ArcGIS |
| User Interface | Graphical desktop |
| Ease of Use | Difficult Not intended for use outside the NIWA research group that developed it. Little work done on user manuals, help screens, or internal checking. |
| Use in Policy Process | Plan (Policy Formulation) |
| Documentation | Rucinski, D., S. Wadhwa, J. C. Rutherford. (2006). ROTAN - ROtorua and TAupo Nitrate Model. User's Guide. Hamilton, NIWA. |
| Support | None outside NIWA |
| Users Forum | None outside NIWA |
| Programming Language | ESRI Visual Basic |
|---|---|
| Methods included for calibration and validation | Calibrated by fitting to measured flows and nitrogen concentrations in streams, and to published annual nitrogen loads entering the lake. |
| Methods included for managing uncertainty | Goodness of fit quantified (RMS error) |
| Analytical Techniques | GIS |
| Model Structure |
Based on the Scandanavian HBV and HBV-N models. Soils and aquifers are modelled as a series of fully-mixed reservoirs (buckets) connected in series and parallel. |
| Keywords | Nitrogen, Land use, Lake, eutrophication |
| Linkages to other Models | |
| Key References | Nitrogen exports from Lake Rotorua catchment - Calibration of the ROTAN Model. http://www.boprc.govt.nz/media/33484/Report-090806-NitrogenExportsLkRotoruaCatchment.pdf |
This report details a third piece of work in a series prepared for Bay of Plenty Regional Council. It outlines recent refinements made to the ROTAN model and describes several scenarios of land use change and mitigation. Findings are intended to help managers develop policy by estimating the extent of export reduction required to meet the lake target of 435 tN/yr and how quickly the load to the lake is likely to respond to such reductions. The results will be used by the University of Waikato to predict likely changes in lake water quality.
Read moreRutherford, J. C., C. C. Palliser, et al. (2009). Nitrogen exports from the Rotorua catchment - calibration of the ROTAN model. NIWA Client Report, NIWA, Hamilton: 62.
Rutherford, J. C., C. C. Palliser, et al. (2011). Prediction of nitrogen loads to Lake Rotorua using the ROTAN model. Hamilton, NIWA: 178.
Rutherford, J. C., A. B. Tait, et al. (2008). Water balance modelling in the Lake Rotorua catchment. NIWA Client Report, NIWA, Hamilton: 47.
