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DELFT-FEWS is a location oriented system. All time series data must be referenced to a (geographic) location. Scalar time series need no additional information. For grid time series data, each point in the grid must be referenced to a location in a grid structure.

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In an unstructured grid the data can be defined either on the nodes, the edges or the faces of the mesh (staggerLocations). Also see http://ugrid-conventions.github.io/ugrid-conventions/#data-defined-on-unstructured-meshes. Note: the start_index attribute connected to for example edge_faces variable should always have value 1 (value 0 will throw unclear error message in FEWS).

Each grid definition in grids.xml is valid for only one staggerLocation and this should match the staggerLocation of the data that you are going to import using the grid definition. The staggerLocation on which the data is defined can be deduced from the data variable in a netcdf file that contains the data to import. The data variable (e.g. "water_level") has an attribute called "location" and a dimension (e.g. nmesh2d_face) that both indicate its staggerLocation. In the grid geometry choose the corresponding staggerLocation. If you want to import different data variables that are defined on different staggerLocations in the same mesh, then you will have to create separate grid definitions for different staggerLocations using the same mesh from the same netcdf file, e.g.:

<irregular locationId="SFBayFM_data_on_faces">
    <netcdfFile>
        <file>sfbay_flowgeom.nc</file>
        <geoDatum>UTM10N</geoDatum>
        <meshTopologyVariableName>mesh2d</meshTopologyVariableName>
        <staggerLocation>face</staggerLocation>
    </netcdfFile>
</irregular>
<irregular locationId="SFBayFM_data_on_nodes">
    <netcdfFile>
        <file>sfbay_flowgeom.nc</file>
        <geoDatum>UTM10N</geoDatum>
        <meshTopologyVariableName>mesh2d</meshTopologyVariableName>
        <staggerLocation>node</staggerLocation>
    </netcdfFile>
</irregular>

D-Flow FM (Dutch: D-HYDRO)

It is possible to use a D-Flow flexible mesh (D-Flow FM) flowgeom UGRID NetCDF file, produced by a D-Flow FM model run, as grid definition in Delft-FEWS. If your D-Flow FM model run does not produce a flowgeom file, then add the following line in the D-Flow FM .mdu file in the output section, e.g.:

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<regular locationId="QPF">
	<description>QPF Grid for ABRFC</description>
	<rows>159</rows>
	<columns>335</columns>
	<polarStereographic>
		<originLatitude>90.0</originLatitude>
		<originLongitude>-105.0</originLongitude>
		<scaleAtOrigin>0.933</scaleAtOrigin>
		<equatorRadius>6367470.0</equatorRadius>
		<poleRadius>6367470.0</poleRadius>
	</polarStereographic>
	<gridCorners>
		<geoDatum>WGS 1984</geoDatum>
		<upperLeft>
			<x>-106.67471389477944</x>
			<y>39.37455858318055</y>
			<z>0.0</z>
		</upperLeft>
		<lowerRight>
			<x>-92.34455929643786</x>
			<y>32.390342856654044</y>
			<z>0.0</z>
		</lowerRight>
	</gridCorners>
</regular>

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Generating XML

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For NetCDF and GRIB files you can generate the grids.xml with F12>Clipboard>Copy grib geometry form file