Sometimes grid cells are located on land while making grids. So, we can use the The delete grid nodes feature is used to remove those unwanted cells. This is especially useful when there are cells outside the waterbody. The delete grid node feature is varied and can be accessed from different options as described below for each case. A proper approach for a specific need can be selectedcan be used to delete a single node, a block of cells, or cells within a polygon as described below.
Delete single grid node
Suppose that Once a grid is loaded in the workplace. The , the following steps describe how to delete some the unwanted grid nodes of that grid.
- LMC on the grid layer in the Layer Control to select the grid want to work with.
- From the main toolbar, select the Delete node button then LMC on a grid node to delete node as shown in Delete Grid Node 1149927473. Keeping LMC on other nodes will delete the selected those nodes also. To escape end using the delete grid node function, click the select object button from the main toolbar or press the S key.
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Figure 1. Delete single grid node.
Delete grid nodes with a grid block selection
For this option, we can remove nodes inside or outside of the selected grid block.
- LMC on the grid layer in the Layer Control to select the grid want to work be worked with.
- From the main toolbar, select press Select objectObject button then LMC on a grid node, the selected node will be highlighted.
- Hold the Shift key and LMC on another grid node (that one is not on the same grid line with as the previous one), and the grid block defined by the two selected nodes will be highlighted (Delete Grid Node1149927473).
After step 3 above, now we can delete nodes inside by accessing the Grid menu, select and selecting the Delete Selected Grid Block option. Alternatively, or RMC to display options then select Grid Grid Block option, as shown in Delete Grid Node 1149927473. To delete grid nodes outside a grid block, select Delete Grid Nodes Outside a Block option from the RMC 's options, as shown in Delete Grid Node 1149927473.
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Figure 2. Select a grid block.
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Figure 3. Delete nodes inside a grid block.
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Figure 4. Delete grid nodes outside a grid block.
Delete grid nodes with a polygon
For this option, we can remove nodes inside or outside of a polygon. The polygon can be loaded from an external file or instantly after drawing a new one. You can also use the Polygon Selection Mode to select grid nodes as well.
- From the main toolbar, click Add a new polyline button then start drawing the polygon by LMC and end by RMC (the polygon overlays the grid) as shown in Delete Grid Node. In case, 1149927473. If the polygon file is available from an external source, skip the drawing polygon steps and load the polygon file into the workplace.
- Select the Select object button from the main toolbar, select the overlay layer (the polygon layer) in the Layer Control panel and then . Then LMC on the polygon , and it will be highlighted.
- LMC on the grid layer in the Layer Control. it means selecting the grid that we want to delete nodes.
- The While the selected polygon is still highlighted, now RMC to display various options. Select Delete Grid Nodes Inside the Selected Polygon to delete the grid nodes inside the polygon or selecting Delete Grid Nodes Outside the Selected Polygon to delete the grid nodes outside the polygonas shown in Delete Grid Node 1149927473.
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Figure 5. Draw a new polygon that overlays the grid.
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Figure 6. Delete grid nodes inside/outside a polygon.
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