4. CREATING AND EDITING DATA
4b. Creating points
4b. Creating Points
Because editing your feature classes can become complex, we’ll start with the simplest one to edit first and progress from there. Here are the steps for editing your bedding (point) feature class:
1. Select you point shapefile from the “Create Features” window. Look at the lower half of the window, there should be a sub-window named “Construction Tools”. You will use these to actually create the points.
2. Notice that at the bottom of the “Create Features” window there are two tabs- one labeled “Attributes”, and the other “Create Features”. The “Attributes” tab opens the Attribute table, where you can edit the attributes of your shapefiles (such as strike and dip of bedding, for example). Make sure that you’re in the “Create Features” tab.
Note: You can also access the “attributes” table through the Editor Toolbar.
3. Zoom to an area on your map where you have strike and dip data.
4. From the Editor Toolbar, select the Editor Arrow, then click on “Point” from the “Construction Tools” sub-window.
5. Next, click on one of your bedding measurements from your field map. This creates a new point. Notice that the point is highlighted in blue, indicating that it is selected.
6. Now, go to the “Attributes” tab at the bottom of the “Create Features” window. This brings up a dialog where you can enter in (manually) the attributes of your point. For example, if you are creating a point to represent a bedding measurement, you will enter in the strike (in azimuth) and dip (in degrees) in the Attribute Table.
7. Once you’ve set the attributes for the point, click on the next point. The attribute table automatically switches to the new point, and you can enter in its values. Repeat this process for all your bedding data points.
8. A good idea while you’re editing a feature class is to go to the Editor toolbar and select Editor –> Save Edits. This will save any changes you’ve made to the feature class. DO THIS OFTEN!!!
9. Now you have a bunch of dots on your map, that don’t really look like strike and dip symbols. Let’s fix that. Double-click on the bedding layer in the Table of Contents. This opens up its “Layer Properties” window.
10. Click on the “Symbology” tab. Under where it says “Symbol”, you’ll see a box that has the dot symbol that currently represents your bedding points. Click on this box to open up the “Symbol Selector” window. This window contains all the point symbol libraries in ArcMap, and the name or brief description of the symbol.
11. To choose the strike and dip symbol, click on the “Style References” menu, and select “Geology 24K”. Scroll down to the appropriate geologic map symbols, and select “Inclined bedding- Showing strike and direction of dip”. You can also use the “Symbol Selector” window to adjust the size and color of the symbols- play around with this as needed. Once you’re done here, click “OK”.
12. Back in the “Layer Properties” window, click “Apply”. All those little dots should now turn into strike and dip symbols. But- they’re all oriented north-south! Easy fix.
13. In the “Layer Properties” window (you should still be in the “Symbology” tab), click Advanced –> Rotation. This allows you to rotate the symbols by a specified amount (i.e. the strike azimuth). From the drop-down menu “Rotate Points by Angle in this field:” select your “azimuth” field. Make sure that the “Geographic” style is selected, then click “OK”.
14. Back in “Layer Properties”, click “Apply”. Now all the symbols will be rotated into their proper position.
15. Finally, click on the “Labels” tab in the “Layer Properties” window. Check the box next to “Label features in this layer”, and make the “Text String” “Label Field:” “dip”. Click “Apply” to see if everything worked. It should, so then click “OK”. Now you have labeled bedding data on your map.
16. Save your project, if you haven’t done so yet.
16.5 You may need to change the size of your symbols so they show up clearly on your map. This process is also done through the “Symbol Selector” menu, in the same window where you originally chose the symbol.