General

Under the General tab the following catchment properties are specified:

·         Area

·         Groundwater model

·         Rainfall-runoff model

·         Runoff time series

·         Calibration plot

·         Load shape

Area

When catchment runoff is specified as specific runoff rates (e.g. litres/sec/m²) an accurate specification of the catchment area is required in order to calcu­late the runoff volume (area * specific runoff). When the runoff volumes are specified as discharges (e.g. m³/s), the catchment area is not used.

Catchment areas can either be assigned manually, or calculated automati­cally based on the catchment shapes on the map by enabling ‘Use catchment shape for area calculation’. By default the calculated catchment areas are used. For sketched catchments a manual specification of the catchment area is normally required, whereas for delineated catchments the calculated area can normally be used. To manually assign catchment area, the option ‘Use catchment shape for area calculation’ must be disabled.

Groundwater model

Three choices are available for the groundwater modelling of the catchment:

·         No groundwater model included

·         Single-layer groundwater model

·         Two-layer groundwater model

A groundwater model can only be selected if groundwater has been included in the Basin modules. By default the menu assumes that there is no ground­water model for the catchment. In such a case groundwater can only be used if the option ‘Unlimited groundwater in catchments without groundwater model’ is selected/enabled.

If a groundwater model is selected, groundwater parameters must be speci­fied under the groundwater tab.

Rainfall-runoff model

By default a rainfall-runoff model is not selected. A rainfall-runoff model can only be selected if the rainfall-runoff module has been included in the Mod­ules menu.

The following types of rainfall-runoff models are offered:

·         NAM

·         UHM

Runoff time series

If a rainfall-runoff model has not been selected a runoff time series must be specified for the catchment. Catchment runoff can be specified either as Spe­cific runoff (volume per time per unit area) or as Discharge (volume per time).

To specify the runoff time series click on the

 button and click Browse... to select an existing time series or click Create a new file… to open the ‘Cre­ate a new file’ dialogue.

When a groundwater model has been included, total catchment runoff is cal­culated by adding baseflow to the user-specified runoff time series. The user specified runoff is not routed through the groundwater aquifers, but repre­sents the fast catchment response. In this case it is important that user-spec­ified runoff time series only include the surface/interflow components of the hydrograph and not the baseflow component. If baseflow is included in the user-specified runoff time series, baseflow will be overestimated.

When a rainfall-runoff model is selected, catchment runoff is automatically calculated and the baseflow component is only included if no groundwater model is present in the catchment.

If the specified time series does not cover the entire simulation period, it will automatically be recycled (cf. ‘Time Series’ in MIKE Zero).

Calibration plot

It is possible to save the calibration plot by enabling ‘Calibration plot’. The calibration plot shows observed and simulated runoff for the catchment, cf. Section 7.1.3.

Load shape

It is possible to import/load the shape of a catchment directly. Click ‘Load shape’, select the relevant shape file and choose the shape item that repre­sents the catchment.

Note: this functionality will only edit the shape of the active catchment on the map. It will not create any new catchment. Instead, it is possible to import and create one or multiple catchments at once from a shape file. To achieve this, please see section Import from Shapefile.