Using ReFH2 to Generate TUFLOW Boundary Inputs: Difference between revisions

Both rainfall and runoff can be generated within ReFH2 and used within TUFLOW either as a direct rainfall boundary or a flow boundary. To generate rainfall or runoff using ReFH2, firstly open the ReFH2 software and create a new ReFH project.<br>

Use the '''‘Import from file’''' option to import the XML files. Importing the xml file will populate the parameters. The XML data canis beavailable is available in catchment valuesdata or point data format. When using the point descriptorsdata format, these do not have an area associated with them. Therefore, youthe user will need to specify the area of the plot that you are interested in (if required this can also be edited later). <br>

Once the parameters have been imported, and the country specified, apply the parameters and choose to move to the next page. On the next page youthe user can choose which rainfall model to use, FEH1999 or FEH2013. It’s possible to specify the design rainfall return periods of interest and ReFH2 will automatically calculate the recommended duration and suggest an appropriate timestep that meets the requirement that the duration must be an odd multiple of the time step. The recommended duration should normally be used, although both values can be edited directly to provide the duration that is required. The XML file from the FEH2013 website contains the rainfall depths for a number of pre-defined return period/duration combinations. For those return period/duration combinations that are not pre-defined, ReFH2 undertakes a two-way interpolation process. ReFH2 will then generate the design rainfall hyetograph based on the rainfall depth and the FSR approach.<br>

On the right hand side you can see the calculated Areal Reduction Factor and Seasonal Correction Factors which will be applied to the rainfall depth. The rainfall profile can vary depending on the season selected (summer or winter) and the seasonal correction factor and areal reduction factor are both applied to the rainfall hyetograph to obtain the correct design rainfall hyetograph.

<li> Urban netNet rainfallRainfall

<li> Rural netNet rainfallRainfall

<li> Total netNet rainRain

The grids can then be exported to csv using the '''‘Export Grid’''' option. This exports the time-varying grids for all return periods and all design outputs.<br>

The relevant data can then be copied into the TUFLOW bc_dbase folder and referenced by the '''bc_dbase.csv''' file as appropriate (see Module 08 for an example of applying direct rainfall boundary conditions for example).

Only distributing to all cells equally represents the surface water mechanism which routes flow from the point it falls, the other approaches work on the assumption that the flow ends up either at the lowest cells, at 1D pits or within channels within the model domain.<br>