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With the release of EEMS 12.0, it is possible to revise the coordinate system (CS) of working projects. This feature is useful when the projection of an imported project is not specified correctly, resulting in inaccurate visualization and spatial analysis of gridded data. To view and modify the currently applied coordinate system, go to Model in the main toolbar and select Project Settings option (Figure 1). The Project Settings window, which accommodates three sections General, Default Precisions and Coordinate Projection, appears as shown in Figure 2.

Figure 1: . Project Settings option

Figure 2: . Project Settings window

Click on the Coordinate Projection section, and the currently applied or selected coordinate system is immediately presented in the window. As noted in the Warning: EFDC+ supports only Universal Transverse Mercator (UTM) and Geographic Projections. Any changes made will alter the projection of the model grid permanently, thus affecting multiple modelling functionalities.

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Once the desired projection is selected, click OK to apply changes to the project.

Figure 3: . Coordinate System settings

Figure 4 shows a dialog that allows defining a UTM projection with some specific parameters. The scale factor of 0.9996 is applied for the zone width of 6° of longitude, and the scale factor of 0.9999 is applied for the zone width of 3°. The central meridian indicates the central meridian longitude of the zone. The latitude of the original is usually taken as zero, and the false easting is usually taken as 500 000 meters. The false northing is taken the zero value for the Northern Hemisphere and is taken the value of 10 000 000 meters for the Southern Hemisphere.

Figure 4: . Define coordinate system with projection parameters based on UTM and WGS 84


Figure 5: . Define projection by importing a *.prj file

Figure 6 shows a dialog that allows users to download projection information from the Internet using an EPSG code. EPSG codes for different CSs can be found at https://epsg.io or https://spatialreference.org. The EPSG codes for the projection information for UTM zones have the form EPSG:326xx. For example, the EPSG code for UTM Zone 10 is EPSG:32610, so users can enter the value of 32610 into the search box to download its projection information.

Figure 6: . Define projection using EPSG Code

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