The general process is to
Use the following resources to help fill in the details for this process:
Before you start the process of physically creating a new data layer, you need to have thought through the data design issues for both the geographic part (point, line, polygon?) and the attribute table (what information do you need in the table, will you use codes, what type will each field be, how long does each field need to be, what will be the field name, taking account of the 11 character constraint, plus no spaces).
For farm field data, this can be as extensive as you want it to be. Or it can be as simple. You may choose to simply have the field id, field name, and the size of the field. Down the road, other tables that hold more field information can be attached or joined by a unique field (field id). For example a CropWare database can be linked to the GIS shapefile and all of the field-based information from CropWare can be linked directly to the individual fields from the GIS. This will allow you to create thematic maps for any farm, including spreading schedules, fertilizer recommendations, etc.
GIS Data Creation
Creating the geographic feature (point, line, or polygon)
Open ArcCatalog. You can create a new shape file in ArcCatalog by using the File-New menu. Note that you must already have navigated to a folder in which you want to create new files, otherwise when you choose File-New, there will be no options for shapefile.
When you choose File-New, you must specify a new shapefile name and feature type (point, line, or polygon).
You can click in the Name field and enter your shapefile name. There can be NO spaces in the name. If a space is needed use the underscore (_) key.
For all farm field data you will use polygon feature types. Use the dropdown menu to choose the polygon feature type.
You should also specify a coordinate system by pressing the Edit... button. You will be creating all of your shape files in the same coordinate system as the aerial imagery, the coordinate system should be UTM NAD83 (meters) Zone 18. You can specify this either by pressing Edit, then Select, then choose Projected, then navigate to the desired coordinate system. Or you can press Edit, then Import, then navigate to an existing shape file for which the coordinate system is specified. I have provided the aerial imagery index shapefile that already has a defined coordinate system for you to use for all of your new shapefiles.
You will use the following window to set your coordinate system. When you have imported the correct coordinate system, click OK.
Now you will be taken back to the Create New Shapfile window where you will see that, in this example, you now have your new polygon shapefile named Stow with the correct coordinate system, NAD 83 UTM Zone 18, defined in the Spatial Reference section of the window.
Click OK and you will be taken back to ArcCatalog where we will go on to the next step.
Creating the attribute table
The creation of the attribute table for a new shapefile is separate from the creation of the shapefile itself. Once you have created the shapefile as described above, you need to find that shapefile in ArcCatalog.
In ArcCatalog, right-click on the new shapefile and choose Properties
Click on the Fields tab and add your new fields. For any fields you add, you will need to name the field (maximum of 11 characters, no spaces), define the field type, and depending on the type, define the other field properties of that field (e.g., length - make sure the length is long enough to fit your longest value). You can add to these later, but this is the easiest place to set up a table.
The new shapefile will already have a set GIS id field called FID, (feature id) that is automatically set by the program. This is something that is set and the user cannot change. There will also be a shape field which is used by the program and an id field that contains a numerical integer value. These three fields are for the program to use and should not be edited.
You can create your own fields to store the data you need. For farm field data I prefer to add an attribute called field name. This can have the field name the grower uses (make the type text, make sure it has enough character space for your names). I also like to have a consultant id field for any identifier you might use. You do not need to put in an area field, there is a tool for that in ArcMap. Add any other fields you know you will need. Then click OK. See the following window.
Go to Part 2 - Digitizing Field Boundaries in ArcMap
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Last Updated 6/16/05