Exercise 1 – Displaying Data in ArcMap

Environmental Resources 372:362

Intermediate Environmental Geomatics

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ArcCatalog

We start with ArcCatalog because we start with the data and then we analyze, and map.  ArcCatalog is the module in which you manage your data (which will eventually be quite complex).  ArcCatalog is designed to resemble (eerily) Windows Explorer, so some of it will come naturally.  You should:

  • Start it
  • Connect to the \\ad-rsc\data folder - your main source for in-house data
  • Go to the class folder: \\ad-rsc\data\teach\intgeo\ Everyone should have their own folder for assignments.
  • Browse around the folders.  Note the different icons for coverages and shapefiles and directories
  • View some data layers from:    \\ad-rsc\data\teach\intgeo\classwork\hopewell\
    • Read the metadata in different formats:  FGDC, ESRI, xml
    • Look at the Preview
    • Look at the map
    • Query the map
    • Look at the table
    • Check out the different "menu bars"

How would you copy some files from one directory to another?  Why would you do that? Answer these questions for yourself. You don't have to submit the answers to us.

ArcMap

Well, ArcCatalog is fun for a little while, but sooner or later the beige maps get kind of old.  ArcMap is where you do most of the mapping

  • Start it -- From inside ArcCatalog
  • Add data with the Add Data button
  • Drag some data from ArcCatalog to ArcMap
  • Zoom around
  • Display vs. Source
  • Adjust the display, categories colors, hierarchy, organization of the map/data
  • Add layers from different projections
  • Query the map (identify tool)
  • Select some things (counties, or cities or roads)
  • Print Layout vs. Map
  • Layout Design: Add compass, scale, etc.
  • Right-click on anything and everything, including:
    • The data layers
    • The legend
    • The layout tab

ArcToolbox

ArcToolbox is the GIS powerhouse.  It is where you can analyze and DESTROY datasets in a matter of seconds. You can access from either ArcMap or Arc Catalog - look on the toolbar.

  • Open ArcToolbox if it isn't already showing
  • Look at -- but don't "touch" -- the different boxes of tools . Some of the most-used toolboxes include:
    • Data Management Tools -- Generalization, Geodatabase, Projections, Tables, Topology
    • Analysis Tools  --  Extract, Overlay, Proximity, Statistics - for vector data
    • Spatial Analyst Tools -- Analyses for raster for data
    • Conversion Tools   -- Export and import to/from different data sources
  • Each tool starts up a small dialog box in which you can choose certain files to modify or analyze.  The dialog box also allows you to set any relevant parameters.

Notice that you can create your own set of tools and keep them in a custom toolbox.  If you worked in an office with specialized tasks, that could be really important.

Displaying Data

Now that you’ve learned some of the basics of ArcCatalog and ArcMap, let’s get into the fun stuff, displaying your data. You will have to hand in answers to the bulleted questions as part of your assignment, so you may want to take notes on them as you work through the lab. You can write your final answers on the back of the map you hand in.

Projections

Although we'll talk more about them as the semester progresses, you should by now be a little familiar with map projections. Now we can take a look at them. Open ArcMap and add \\ad-rsc\data\teach\intgeo\ClassWork\avdata\world\cntry04 and latlong. Right click in the data frame and open its properties. Click on the Coordinate System tab. In the Predefined folder, you can choose between Geographic Coordinate Systems and Projected Coordinate systems.

  • What is the difference between the two?

Now play around with the different projections.

  • If you use a projection that is designed for North America, how are the other countries affected?

Now look at how the world projections differ.

Insert a new data frame. Add to it \\ad-rsc\data\teach\intgeo\ClassWork\avdata\usa\states and cities. If you need to switch data frames, right click on the data frame you want to see and active it. Display only those cities that are state capitols (hint: definition query tab in the cities layer properties). Use the measuring tool to measure the distance between Sacramento, Ca and Trenton, NJ.

  • What is the distance in meters when you project the map in North American Albers Equal Area Conic?
  • What is the distance when you project the map in USA Contiguous Lambert Conformal Conic?

Symbology Step1

We are now going to make a variety of State maps, displaying 2003 population data in a few different ways. Remove the cities layer from your dataframe. Now you will make a Choropleth Map, using the Symbology tab of the states layer. Under quantities you will find an option for graduated colors. Display the 2003 population data. Now play around with the classification and normalization.

  • How does the map change when you normalize the 2003 population with area?

Now add states again. You can add the same data layer many times and change each one individually. With this one we will make a map of the US using graduated symbols instead of graduated colors. The display changes dramatically.

Add states again. This time make a dot density population map. Change the dot value to equal 200,000. Now try 20,000. You can also change the color and size of your dots.

Now say you would like to look at a US population map, but you also want to know what region each state is in. To do this, add states again. Choose multiple attributes under the symbology tab. This allows you to put both attributes onto one map.

  • What is the population of Florida?

Symbology Step 2

Insert a new data frame and name it hopewell . Add ad-rsc\data\teach\intgeo\classwork\hopewell\hoperoad and hopegeol. Use the symbology tab to look at the hopegeol map using the prim-geol field. Now label features. All of the polygons are now labeled, but this can be overwhelming. How can we label only what we want labeled? Go to the layer properties window and then the labels tab. Now label only those polygons that have an area greater than 1.0x107. You can also change the size, font and color of your labels.

Now activate the hoperoad layer. Label all roads. Notice when you zoom in more and more roads are labeled.

Map Layout

"The quality of a map is also in part an aesthetic matter. Maps should have harmony within themselves. An ugly map, with crude colors, careless line work, and disagreeable, poorly arranged lettering may be intrinsically as accurate as a beautiful map, but it is less likely to inspire confidence." John K. Wright

So now you know some of the many, many ways to display your data. How are you going to make a printable map out of all this? What do you need to make a map complete? Go to the layout view. You will have all your data frames on this layout. You can delete the ones you don't wont, and you can activate a data frame to make changes to it by clicking on it in the layout or right-clicking on the data frame name in the table of contents and selecting activate. For a good map, you need the following elements: data, title, legend, data source, north arrow and scale bar. Your title, legend labels, and data source information should be clear yet concise.

A few considerations:

  • Prioritize: The most important map elements (usually the data, legend, and title) should have the greatest visual impact. Position, color, and size all influence an element’s visual impact. Use space effectively so that you maximize the scale of the map in the available space.
  • Choose colors carefully: Try to make colors intuitive for the map reader (e.g., water is blue). Color choice affects how the map is perceived.
  • Text: Fonts (especially for labels) should be no smaller than 8 point to maintain readability. Play around with serif vs. sans-serif fonts, size, bold/italic, etc.
  • Legend: Make sure class ranges only include the data being mapped. Headings and labels should make sense (i.e., not obscure abbreviations from the attribute table).

Assignment

  1. Answer the bulleted questions in the Projections and Symbology 1 sections of the lab exercise. You can answer them on the back of one of your maps.
  2. Using an appropriate projection (or projections), make a map with charts or graphs showing the ethnic make up of each state (the data is for the year 2000). Two of the field names for the ethnicity data are obscure (AMERI_ES = Native Americans and Eskimos, HAWN_PI = Hawaiian and Pacific Islanders).  Also note that if you add up the populations of the various ethnicities, it exceeds the total population of the state in 2000.  Why?
  3. Make a map of Middlesex County focused on a data layer that interests you (ie. streams, roads, geology, etc.). Look in \\ad-rsc\data\teach\intgeo\Classwork\avdata\midco for data. Label this data. Your map should also show New Jersey with Middlesex County indicated in some fashion.  Your map also needs to have all the essential elements listed above. The layout and composition of this map counts so make it pretty!  You will undoubtedly need to use additional layers for context.  If you dare, look in \\ad-rsc\data\databank for additional data.

Hand in the assignment on Monday, February 2nd.