Edit the Catchment Average Processing (grids)

How does it work?

Radar Actuals

The Nimrod actual rainfall files are instantaneous values at 15 minute intervals. This means that the radar file from T1=00:00 contains the intensity mm/hr at 00:00. The radar file from T2=00:15 contains the intensity mm/hr at 00:15.

In NFFS the Nimrod radar actual data is processed using the following steps:
1. Import original Nimrod data files and convert them from mm/hr to mm. There is a fixed factor of 1/32 and a mm/hr to mm factor of 1/4. The total conversion factor on importing is then 1/(32*4) = 0.0078125.
2. Show the Radar Actual Nimrod grids in the spatial display. These are still the values at the 15 minute time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.
4. Nimrod processing: in this Module Instance the radar actual 15 minute interval values are averaged over the time interval of 15 minutes. Therefore the CatAvg Radar Actuals value at T2=00:15 is the average rainfall value from the two intensity values at T1=00:00 and T2=00:15.

Radar Forecasts

In NFFS the Nimrod Radar forecast data is processed using the following steps:
1. Import original Nimrod data files and convert them using a fixed factor of 1/32. The total conversion factor on importing is then 1/32 = 0.03125.
2. Show the Radar forecast Nimrod grids in the spatial display. These are still the values at the 15 minute time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.

NWP Forecasts

In NFFS the Nimrod NWP forecast data is processed using the following steps:
1. Import original Nimrod data files and convert them using a fixed factor of 1/32. The total conversion factor on importing is then 1/32 = 0.03125.
2. Show the NWP forecast Nimrod grids in the spatial display. These are still the values at the 15 minute time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.

NWP Temperature

In NFFS the Nimrod NWP temperature data is processed using the following steps:
1. Import original Nimrod data files and convert them using a fixed factor of 0.1.
2. Show the NWP temperature Nimrod grids in the spatial display. The values at the 1 hour time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.

MOSES Evaporation

In NFFS the MOSES Evaporation data is processed using the following steps:
1. Import original Nimrod evaporation data files and convert them using a fixed factor of 0.0014388.
2. Show the MOSES Evaporation grids in the spatial display. The values at the 1 hour time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.

MOSES SMD

In NFFS the MOSES SMD data is processed using the following steps:
1. Import original MOSES SMD data files and convert them using a fixed factor of 1/32. The total conversion factor on importing is then 1/32 = 0.03125.
2. Show the MOSES SMD grids in the spatial display. The values at the 1 hour time intervals.
3. Spatial Interpolation, average of the Imported grids to catchment polygons.

How to edit the catchments

To extend the Catchment Average process with some new catchments the following steps should be carried out:
1. For each catchment add a new location representing that catchment to the Locations xml-file, if it is not available yet.
2. Add new shape for each new catchment to catchment shapefile (the file which is used in the catchment average process can be read from the Polygon xml-file). Each new shape should be provided with a shapeId in the shapeIdAttributeName column as specified in the Polygons xml-file. This shapeId should be unique and exactly matching the shapeId from the Polygons xml-file!
3. Amend the Polygons xml-file by adding a new shape item for each new catchment. The shapeId should be matching with the Id used in the shapeIdAttributeName column in the shapefile. The locationId should be matching the locationId in the Locations xml-file used for that catchment.
4. Add the new catchments locationIds to the locationSets representing the catchments as used in the Catchment Average process. For catchment averaging of Nimrod data the ModuleConfigfile Nimrod_Spatial_Interpolation is used.
5. Check if all displays use the same locationSets with the new catchments or add the new catchments to all other relevant locationSets.

Note: Changing the shapefile with catchment polygons and changing the polygons xml-file will have effect on every catchment average process using the same catchments as these polygons and their relation with NFFS are defined only once in the configuration.