Lab 1, Part 1

Creating a Map in ArcGIS

As explained in the introduction “ArcGIS the Software”, the basic file used in ArcGIS is called a shapefile or feature type. They are basically the same, however, in the latest version of the software, the term feature type is used because so many users create “Geodatabases”. In this class we will not work with “Geodatabases”, mainly because in the many years that I have been working with GIS, I have never had the need to create one.

For many projects, you will need to create your own data because digital files will not exist, especially if you are creating a footprint of a new building, bridge, road, etc. I feel the basic place to start is learning how to create your own data so you have a feel for what a shapefile is.

Step 1. Accessing ArcGIS and creating a new map.

The objective of this assignment is to create your own map that is made up of polygons, polylines, and points. In order to do this, we will do heads up digitizing, which means digitizing on screen.

On your computer, create a folder directly on the C or D drive (or X drive if you are using the CVEEN server Doug Ressler introduced you to) without any spaces: (C://GIS). Within this folder you can create folders for each lab and that way they will be organized correctly. ArcGIS has several tools that does not accept spaces, you can use an underscore instead of a space when needed.

Before you begin the Lab, you must download the only file you need for this lab. Right click on the link (ftdoug.tif) below and right click, select Save Target As….from the drop down menu. A window will appear that will let you save it to whatever folder you want.

Find the ArcMap 10 icon on the desktop or go down to the Start icon in the lower left and click on All Programs, then on ArcGIS, and ArcMAP 10. To create a new project (in this case your first project which will be Lab 1, you will click on “New Maps” “Blank Map” or just close the first window that pops up by clicking on Cancel.

Click on the + sign and add ftdoug.tif, you may have to click on the “Connect to folder” button (fifth icon to the right of the Look in: window) and navigate to the directory where you saved the tif. When you add it you will be prompted to build pyramids.  Click on “Build Pyramid”, you should only have to do this once. This means: (In raster datasets, reduced resolution layers, or pyramids, record the original data in decreasing levels of resolution. The coarsest level of resolution is used to quickly draw the entire dataset. As you zoom in, layers with finer resolutions are drawn; performance is maintained because you're drawing successively smaller areas).

The Ft. Douglas map that you see is what you will be using as your backdrop to create new shapefiles. Heads Up Digitizing refers to tracing the different features with your mouse and saving them as new files. You will be creating “Shapefiles” to represent roads, buildings, the Wasatch Forest, the University area, the Fort Douglas area, etc. In order to create a new layer, for example if you are adding roads, you must start by creating a new shapefile in Catalog, which (from the Intro to the Software) is found on the right side of your screen. You can click on the push pin icon and it will dock it to the right margin and will show a tab that says Catalog. Leave it docked and just click on the tab, to bring up the Catalog menu. Click on the “Connect to folder” button and navigate to the directory where you want the file to reside. Right click on the folder name and select – “New – Shapefile”, here you can name your shapefile and specify what feature type you want to input, whether it is a point, multiple points, polyline, or polygon. You also have the choice of defining the coordinate system. For example if the base map is in the UTM projection, NAD 27 (North American Datum) and in the northern zone 12, click on Edit and then on Select and then on Projected Coordinate Systems. Double Click. You will bring up a number of different projection systems, go down to UTM and double click. Then double click again on NAD 1927 and again on NAD 1927 UTM Zone 12N.prj

Add your new shapefile to ArcMap - click on + (ADD) or drag it from Catalog and drop it in the Table of Contents. The Table of Contents is also referred to as TOC (left hand column of your window. If it disappears from the View, go up to the Main Menu bar at the top and click on Windows. In the drop down menu, select Table of Contents and that will activate it once again).

Begin Digitizing

1. The first thing is to add the shapefile(s) you just created. You can create several shapefiles at the same time, as the steps have to be repeated. I recommend creating two road shapefiles (polyline), Primary and Secondary, two area (polygon) shapefiles, one for the Salt Lake Urbanized area (pink area in the map), cemeteries, and the Wasatch Forest) and one for the large buildings on campus, and one point shapefile for the smaller buildings. The files should be located in the directory on your hard drive or the X drive if using the CVEEN server. Next, you want to have the FtDoug.tif checked on so that you can use the map as a backdrop for creating your roads and buildings, add the following shapefiles, Primary and Secondary Roads.

For the Primary Roads add: South Temple, 4^th and 5^th South (5^th South to the intersection with Sunnyside), Sunnyside between 13th East and where it intersects with Foothill, and 7^th East.

For the Secondary Roads add: Wasatch Drive, 13^th East, 2^nd South beyond 13^th to the U where it intersects with President’s Circle, (the U driveway around the Park Building), University Street between Shriner’s Hospital (red circle) to 5th South (see blue line below).

For polygon features, add: the Mt. Olivet Cemetery, Mt. Calvary Cemetery, a few buildings of the VA hospital, a few buildings in the U (i.e.: Park Building), Marriott Lib., Huntsman Center, Merrill Eng., Shriner’s Hospital and the U hospital. Two overall areas I would like you to add and these will be polygons, are the Wasatch Forest area, which is the area represented in green and the Salt Lake urbanized area which is represented in pink. I will show you how to make the color semi-transparent if you want to superimpose layers on top of these. If you want to add more than what is listed, feel free.

Add the following points: Across the street from the Shriners Hospital by the City Cemetery and Mt. Calvary, there are several buildings that appear. Digitize those as points.

To digitize, click on Editor (the Editor tools - if it is not visible, you will find it under Toolbars in the dropdown menu by clicking on Customize). Click on Start Editing and before you begin digitizing, you will want to set your snapping environment, this will allow you to close features, without gaps. You do this by first clicking on Snapping in the drop down menu in the Editor toolbar. Click on Snapping Toolbar and another window appears with symbols of the segments that will be snapped to (point, vertex, end, edge). The Snapping dropdown menu offers more options and at the bottom you can use this menu to change the snapping tolerance from 7 to 10. With this tolerance you should be able to see the digitizing tool snap to the feature. 

In order to add data to the new shapefile, (or edit features in a shapefile) the shapefile must be active. An active file in Table of Contents on the left side of your ArcMap window is highlighted. If you click on any shapefile name it will have a dark box that appears around the name, this indicates that it is active. When you activate your Editor, the Create Features window appears on the right side of the View window. You must also have the name of the shapefile you are editing in this box highlighted or activated. Very important, when you are changing from one shapefile to another, for example, if you are adding two types of roads from the map and you have separate shapefiles for highways and secondary roads, make sure that the shape file is active in both the Table of Contents and in the Create Features window, if not, the edits will not be saved. In other words it has to have a blue box around the shapefile name in both places. When you being to set up your Edit session, you may get a window that says: “Start Editing encountered one or more layers with warnings. You may not be able to edit some layers if you continue.” You can click on Continue; usually with no problem, this has to do with differences in spatial reference for the most part. The spatial reference from the file you are using as your backdrop data set will set the data frame spatial reference, but it may be that you did not define a spatial reference for the shapefile when you created it. However, for this lab you can click on Continue and it will be OK. (If the files are not in the coordinate system you want the project to ultimately be in, you can re-project them. We will have several labs that deal specifically with projections and how to re-project if needed, later on in the semester, so for Lab 1, use the projection information from the Ft. Douglas tiff, which is UTM, NAD 1927. (This should remind you of data from the presentation on projections and coordinate systems that you went over last week.)

While in the Edit mode, you can move your base map around if you want to zoom in. If you need to scroll up or down, just move the cursor to your scroll bar and it will allow you to move anywhere you want and still take you back to the position you just came from. You will notice a line extending with the cursor, but it does not add any points as you click outside the window. Same thing if you want to change the shape of the polyline and use another tool. You can go up to the Editor tool box and select another tool from the box just right of the sketch tools and you will not lose your place in the line you are adding. If nothing happens, just make sure to click on the shapefile you are editing in the Create Feature window on the right, that will refresh the Edit session.

To begin digitizing, you click on the tool that has two points (vertices) and trace your feature by clicking with the left button on your mouse. This will create vertices. You can delete segments between vertices, so this can be advantageous in the event of mistakes. To delete a segment, or several, click on Crtl –Z or go up to the Menu bar at the top and click on the “delete” key, the (X). To close of finish a shape, either double click with the left button, or select finish sketch from the drop down menu when you right click using the edit tool (black small triangle next to Editor on Editor Toolbar).

You can save your edits as you create new feature types by going to Editor in the Editor tool bar and click on Save Edits in the dropdown menu. You can also save the ArcMap Documents (*.mxd) as anything you want to call it and save it to your folder for Lab 1.

After you have created all of your shapefiles, you will have lines, polygons, and points in your data view. You can show them all together or separately, by simply clicking in the box next to the file name and a check mark will either appear or disappear. Turn off the base map (Ftdoug.tif) and turn on the other shapefiles.

(You also have an option called Finish part and this is useful when you are digitizing many segments that are related to each other and will have the same attributes, but do not form one cohesive feature. For example, you might have a road that crosses a river and you want the segments, though they will be interrupted by a water feature, to be related. If you select Finish Part, you can digitize to the river, click Finish Part and then start up again on the other side and continue digitizing and when you click them on and off, all related parts will appear and disappear. This drop down menu will give you many other options as well.

Next lab we will create attributes for the layers you created, change layer properties and begin our map layout.

OUTLINE FOR ADDING FEATURE

1. Open a New empty map in ArcMap.

2. In Catalog create a new shapefile. Define as to feature type and define spatial reference.

3. Add new shapefile to ArcMap as one of the layers.

4. Continue same process with each new shapefile that you create.

5. All of these layers become part of the MapDocument, save your .mxd.