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Get Started with GIS Mapping

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Get Started with GIS Mapping Powered By Docstoc
					Get Started with GIS Mapping

     Part 1of 2, January 2010
       Madhu Lakshmanan
Agenda for this section
   Brief introduction to GIS/mapping jargon
   Exploring Google Earth (GE)
   Point Maps versus thematic maps on GE
   Base Maps and where to find them
   The Census website
   AFF Mapper – Part 1
   The Census KMZ Mapper Application
   Data Preparation – geocoding
   Mapping point data
   Resources/Homework
What is GIS
 Mapping
 Wide spectrum of complexity
 Combination of hardware, software &
  data
 Can be one single large system or a suite
  of tools or one small tool depending on
  your requirement
 Data is key, design and color makes it
  more informative and appealing.
Terms that we will come across
   Layer – A slice of the geography of a particular area. On a paper
    map, one layer could be the roads, another could be parks,
    another could be places of interest.
   Base Map – A layer that lends context to your data
   Geocoding – Converting street addresses into spatial data that
    can be displayed on a map (usually a latitude and longitude pair)
   Shapefiles – A data format that stores a particular geographic
    feature of a certain area. (it is usually a set of files) and is almost
    the de-facto standard. It is an ESRI-created format.
   KML/KMZ – an XML based language schema for expressing
    geographic visualization. It is an official open standard for all
    geobrowsers.
   Projection – transformation of a map from a spherical object
    (Earth) to a flat sheet of paper.
             Google Earth                   Navigation
                      Toggle                Controls
                                3D Viewer
                      Sidebar


  Search
  Panel



    Places
    Panel
Transparency
Control


    Layers
    Panel
Exploring Google Earth
 Copy Image/ Print Scr
 View Menu
 Tools – Options
 Navigation
 Fly to
 Layers
 Adding your own placemarks to a folder
  and saving a KML file
Google Earth – some best practices
   Play, Practice, Patience
   Save as and keep your KML files organized in a
    separate folder on your drive.
   Clear cache regularly after saving required data
   Save without too many standard layers to keep
    kmz size down for emailing etc.
   Use transparency slider
   Actual screenshots are better than using the
    inbuilt GE copy tool – only copies the GE map
    and not any of your custom overlays
   Look at KML in free time – very much like
    XML.
Point Maps versus Thematic Maps
 Point Maps usually give you information about a
  particular location on a map. They can be used
  for directions, descriptions and distance
  information among others.
 Thematic Maps reflect a particular theme
  (social, physical, political etc.) about a
  geographical area. It shows distributions in the
  form of shading or graphs rather than actual
  locations where people live.
 Point and thematic maps can be layered atop
  one another to provide a wealth of information.
Example of a simple point map




Location of major grocery stores in the Ann Arbor vicinity
Example of a simple thematic map from
the US Census




  Percent Population below poverty by county in North Carolina.
Data Preparation - Planning
   Having some idea of what you want to achieve
    with your map
   What data do you have already?
   What data do you need to acquire?
   If you have to convert your data, what
    conversion tools do you need?
   What maps can you reuse?
   Data origin, metadata, processing
   Discuss with other users, colleagues, peers
Base Maps
 Base maps or boundary maps help provide
  context to your data map. They do not contain
  any attribute information, they are just
  geography. They can be layered with the maps
  you create to give information that is not
  available or visible on the virtual globe (GE),
  such as county names/zipcodes etc.
 If your mapping concentrates on a certain
  region (state/county etc), you need to create
  your base maps just once and save them, and
  these can be reused as many times as you need.
Example of a base map
                           Zip code
                            boundary
                            map of New
                            Mexico.
Example of a base map
                           County
                            boundary
                            map of
                            New
                            Mexico.
Exploring the Census website




http://www.census.gov/
TIGER/Line Shapefiles from
census.gov
 Note that these are shapefiles and need
  conversion to kml/kmz to be used on GE. (AFF
  Mapper)
 Advantage is that they are the ones that most
  datasets are based on, so compatibility is great
 Download the shapefiles at the level you need,
  by drilling down to your state – county, MSA,
  zipcode etc. (Multiple files downloaded at the
  same time have an unzip problem, hence you
  need to do it one by one)
 Make sure you name your unzip folder
  meaningfully since things will get confusing after
  downloading multiple maps!
AFF Mapper – Basic
 Created to make maps using census boundary
  files and American Fact Finder data
 Rule-based, but simple to follow
 Find a shapefile from http://www2.census.gov/cgi-bin/shapefiles/national-files
  This is a one time task for a particular
  geography, so make sure to extract, rename
  and save the file safely.
 Extract to a folder on your computer that you
  can find. There will be multiple files in the
  folder and they are all important.
AFF Mapper - 1
                    Can be used for 2
                     purposes
                     ◦ To convert
                       shapefiles to KML
                       for viewing on GE
                     ◦ To combine
                       shapefiles with
                       data and
                       converting to KML
                       for viewing on GE.
AFF Mapper - 2
   Click on Input Shape – a browse window will open.
   Navigate to the base map folder that you downloaded and
    unzipped earlier and point to the shp file in that folder.
   Once that file is loaded, you will be able to see all the information
    in a tabular form – these are just geographical information and
    codes and identifiers.
   Ignore the “Join Tables Settings” panel for this exercise.
   In the Label Field column at the bottom, choose a field that will
    appear on the map, choose “Name” if there is such a field. Click
    Render. You can change the color at this point, but remember that
    you can also do it in Google Earth depending on other layers you
    are using, so just say OK with the default color.
   Click on Output KML and give it a name and location – very
    descriptive. I prefer to put it in the same folder as the shp file that
    was used to begin with.
   Hit Go and wait for the “Finished” message. You will now have
    your KML file available to open in Google Earth.
The Census KMZ Mapper




   http://ctasgis02.psur.utk.edu/tokml/Default.aspx
The Census KMZ Mapper
 Downloaded KML visualized in Google
 Earth




Percent Population Without Access to Private Auto in Whole State
Data Preparation - Geocoding
 Can geocode at different address levels
  like state, county, zipcode, complete
  address, etc.
 Multiple ways, differences in accuracy,
  daily limits, one time activity
 Using BatchGeocoder.com
 Using KMLGeocoder on desktop
 Zip data with lat/long for each state
Mapping your case data - points
 Directly enter addresses into GE one by one.
  (can import bulk if using Pro version)
 Use a tool like KMLGeocode or
  batchgeocode.com to take your Excel address
  data and convert to KML directly – no
  identifying info needed other than address data
  and this can even be reduced to street level if
  you wanted to preserve some more anonymity.
  Limit is 5000 a day.
 GE shows a map with a scatter plot of your
  case data. A screenshot of this will not reveal
  any specific address information to a viewer but
  sharing kml will do that.
  Batchgeocode.com




“Run” the geocoder and then Click on the “Download to KML file” button at
the very bottom and you can have a saved file with the latitude and
longitude information for your addresses.
To-Do
1.   Assemble a set of tools for mapping
2.   Begin a library of base files and data files for
     mapping on your computer/server
3.   Find sources of data for your region – many
     local governmental entities and health related
     organizations are good sources.
4.   Think about what sort of maps and
     visualizations work best for each purpose
5.   Discuss maps and mapping practices with
     peers.
Resources and Interesting Mapping
Applications - 1
 Census website
http://census.gov
 American Factfinder
http://factfinder.census.gov
 Google Earth User Guide
http://earth.google.com/userguide/v5/
 Rural Assistance Center Maps
http://raconline/org/maps
 Show@/USA
http://show.mappingworlds.com/usa
Resources and Interesting Mapping
Applications - 2
   Download applications here
http://lsntap.org/GIS_Resources_for_Google_Earth
    ◦   KMLGeocoder
    ◦   EarthPlot
    ◦   AFFMapper
    ◦   Shp2KML
    ◦   Statewise Geocoded Zip codes
    ◦   Regional Legal Aid boundary files
Homework
 Familiarize yourself with Google Earth and also with the
  American Fact Finder part of the Census website
 Go to http://www.justice.gov/eoir/sibpages/ICadr.htm
  Pick any two states (try to pick atleast one with more
  than 1 entry!) and use Excel and batchgeocoder.com to
  plot those addresses on GE and save as a KML file.
  Send me a screenshot of your GE file when you are
  done (to madhu@lsntap.org)
 Download County level and 5 digit zipcode level base
  maps of your state from the TIGER site and try to
  convert them to KML using AFF Mapper.
LSNTAP GIS Resources
   More roundtables and trainings and Q&A
    sessions in the new year.
   GIS mailing list being resurrected – do sign up
    and participate https://lists.mayfirst.org/cgi-
    bin/mailman/listinfo/gis
   GIS Resources section on LSNTAP.org updated
   Set up a meeting with Madhu if you need
    support. Email madhu@lsntap.org
   Send links to any interesting mapping resources
    or data resources you find to
    madhu@lsntap.org

				
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