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Overview

This import is available in DELFT-FEWS versions after 28-10-2009 (FEWS version 2009.02)

Imports grid time series data from NetCDF files which comply to the CF standard. More information about the cf standards can be found at http://cfconventions.org/cf-conventions/v1.6.0/cf-conventions.html. In DELFT-FEWS versions 2015.02 and later this import type can also be used to import data from NetCDF files that comply to the UGRID 0.9 conventions (see https://github.com/ugrid-conventions/ugrid-conventions). For details about the exact formats of NetCDF files that can be imported in FEWS, see NetCDF formats that can be imported in Delft-FEWS.

See also the following two other types of NetCDF-CF imports that are available:

In DELFT-FEWS versions 2011.02 and later this import type can also be used to import data using OPeNDAP, see Import data using OPeNDAP.

Note that for the import to correctly import (irregular) grids, the grid must be configured in grids.xml. There is a tool available to obtain the grid configuration from the NetCDF file in the F12 debug menu (located under "Convert"). Since 2017.02, the import will automatically detect the irregular grid for temporary time series (<timeSeriesType> set to "temporary" or "temporary external forecast"). The imported grid is then temporarily stored along with the data, and can be used within the same workflow, which could for example use a spatial interpolation to map the imported data to a configured grid. Note that this functionality is only available for temporary time series since storing an irregular grid definition can easily take up just as much disk space as the data itself, and is therefore undesirable for data that is to be stored for a longer time period. Also note that this functionality is only available for grids that do not have z-values / z-layers. 

Import Configuration

An example of the NETCDF-CF_GRID import will be given here.

ImportNetcdf_Grid 1.00 default.xml
<?xml version="1.0" encoding="UTF-8"?>
<timeSeriesImportRun xmlns="http://www.wldelft.nl/fews" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wldelft.nl/fews http://fews.wldelft.nl/schemas/version1.0/timeSeriesImportRun.xsd">
	<import>
		<general>
			<importType>NETCDF-CF_GRID</importType>
			<folder>$IMPORT_FOLDER$/NETCDF</folder>
			<failedFolder>$IMPORT_FAILED_FOLDER$</failedFolder>
			<backupFolder>$IMPORT_BACKUP_FOLDER$</backupFolder>
			<idMapId>IdImportNetCDF</idMapId>
			<unitConversionsId>ImportUnitConversions</unitConversionsId>
		</general>
		<timeSeriesSet>
			<moduleInstanceId>ImportNetcdf_Grid</moduleInstanceId>
			<valueType>grid</valueType>
			<parameterId>Snelheid.u.F0</parameterId>
			<locationId>hmcn_zeedelta</locationId>
			<timeSeriesType>external forecasting</timeSeriesType>
			<timeStep unit="minute" multiplier="30"/>
			<readWriteMode>add originals</readWriteMode>
			<synchLevel>6</synchLevel>
		</timeSeriesSet>
	</import>
</timeSeriesImportRun>

Id Map Configuration

An example of the IdMapping used for the NETCDF-CF_GRID import is shown below.

IdImportNetCDF 1.00 default.xml
<idMap version="1.1" xmlns="http://www.wldelft.nl/fews" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wldelft.nl/fews http://fews.wldelft.nl/schemas/version1.0/idMap.xsd">
	<map internalParameter="Snelheid.u.F0" internalLocation="hmcn_zeedelta" externalParameter="velocity" externalLocation="hmcn_zeedelta"/>
</idMap>

Grids Configuration

When importing grids in the FEWS database it may be required to configure the grid characteristics in the grids.XML file. The grid characteristics must be similar to the grid imported from the NetCDF file.

Grids 1.00 default.xml
	<regular locationId="hmcn_zeedelta">
		<description>HMCN Zeedelta Model</description>
		<rows>101</rows>
		<columns>101</columns>
		<geoDatum>Rijks Driehoekstelsel</geoDatum>
		<firstCellCenter>
			<x>54000</x>
			<y>449000</y>
		</firstCellCenter>
		<xCellSize>130</xCellSize>
		<yCellSize>70</yCellSize>
	</regular>

Import of Waterwatch NetCDF data

For the import of Waterwatch NetCDF data a special NetCDF import type can be used "NETCDF-CF_GRID-NW". This import type has been added in July 2011 to the FEWS 2010.01 and 2011.01 builds, and will be available in the 2011.02 build. Waterwatch NetCDF data for Dutch waterboards requires the Transverse Mercator projection to be used. This regular grid projection has been added to the FEWS code in October 2011.

Grids 1.00 default.xml
	<regular locationId="Waterwatch">
		<rows>1309</rows>
		<columns>1049</columns>
		<transverseMercator>
			<originLatitude>0.0</originLatitude>
			<originLongitude>3.0</originLongitude>
			<scaleFactorAtOrigin>0.9995999932289124</scaleFactorAtOrigin>
		</transverseMercator>
		<gridCorners>
			<geoDatum>WGS 1984</geoDatum>
			<upperLeft>
				<x>3.3474039424011828</x>
				<y>53.58134813984449</y>
			</upperLeft>
			<lowerRight>
				<x>7.0253359554942705</x>
				<y>50.572267443880236</y>
			</lowerRight>
		</gridCorners>
	</regular>
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