Now that we have our map projected in the map display of My World, we are ready to begin to begin the process of creating a data layer for analysis. For this project, we are going to create a new layer to build polygons to analyze the land cover that we are able to observe in this aerial photograph.

You need to click on the File menu which will open a drop down window. To create this new layer, select New Blank Layer….

After selecting New Blank Layer, this window will appear. This allows you to create a new layer of data with shape files, grids, or annotations for your data. Since we want to create a new shape file with polygons to represent the areas that we determined the MUC codes for, we will select Polygons. Before creating the area, type in a name on the right. You can also add new fields. A hint would be to ensure that you have a field for the MUC code as that will be used to add the annotation later. Then click Create Layer.

To create our polygon, select the Create New Polygon tool from the Map View. The cursor will change to a crosshair when placed over the map. Simply place the cursor over the first point and left click your mouse as you move the cursor around the area that you are creating the polygon for. You can use as many clicks as you need to create your polygon that matches the area’s boundaries, creating straight lines as well as curves. The default setting is to create a fine black line. The screen capture displays the area, but it is difficult to see unless you are looking for it or created it. The next step will be to modify the appearance of the polygon.

You can select the Layer tab on the main menu and then select Edit Appearance to open the wind above. You can edit the line width by clicking on the down arrow and selecting the width that you desire.

Next select Fill Color to select the color of the line that you prefer. In this case, yellow was elected because it will be very visible on the map. You can also adjust the transparency of the line at this point or do it later. The default setting is 0%, which is completely opaque. Moving the indicator right to 100% will make the line invisible. This can be useful later. Select Apply to apply the changes.

When you finish editing the layer (line width, line color, and adding polygons), click on the  Layer tab and select Stop Editing Layer. The changes will appear on your map and the fields that are seen below the map above will fill in with the area of the polygon and its computed perimeter.

There are a couple of options available to you if you want to add data for new pastures. You can append a new record, which will allow you to create new polygons and the data from those polygons will automatically be added to the data for the first polygon. Another option that may be better will be to click New Record and new lines will be added below the first one where each row of data will apply to the polygon that you create for that row. This will create disaggregated polygons for each of the pastures that we can view in this map. Aggregating the data is as simple as exporting the data to an Excel spreadsheet as a delimited document. This allows you to view the individual data for each polygon.

If you return to New Blank Layer and add annotation, then each polygon created by New Record will be annotated. Appended polygons will not be annotated, only the first record. Either method works fine and is really an individual choice.

Clicking on the Help tab in the main menu bar will open a window where you can access the My World online documentation. Documentation can also be downloaded as PDF files for printing or using offline.

In this view, two polygons were created, each with its own record. The view of the data at the bottom of the Map view indicates that the layer is open for editing. When you Stop Editing Layer, the display will disappear. To view the data for each polygon, left click on the Table icon. The data fields will be displayed for the layer that is active. The bottom display can also be used to add new fields as desired; just remember to click on apply and Stop Editing Layer to save the changes.