Delaware County Data Review

On each of your computers, on the C: drive, is a folder called Delaware Data.

These are Delaware County data sets, some updated by the county as recently as the last few weeks.  You will use these data layers for the mid-term evaluation and course project.

Don’t remove any Delaware Data files from the computers!  I do have this data backed up on a OWU networked drive.

Note: due to a network problem, the Delaware Data is not on computers 4 and 19.  InfoServices is working on the problem and hopefully it will be resolved soon.

In order to familiarize yourselves with the data, please do the following by Wednesday March 4:

• Make a new blog entry and title it Delaware County Data Review. Categorize it as an Exercise (so I can find it).
• In the blog entry, indicate the name of each Delaware map layer. Write a sentence describing each map layer in the blog entry.  If there are multiple map layers in a folder, document each.  Again, the point is to familiarize yourself with the Delaware GIS data for the mid-term and your project.
• If you are confused by a data set, indicate that in your comments.  If the data set is not described, search the web and see if you can figure out what it is.

To view the map layers:

• Start ArcMap and create a new ArcMap project.  Save it as deldata.mxd in your folder in the Geog 355 folder
• Hit the + button to add map layers to the project
• Navigate to the Delaware Data folder and open the first folder.  Add the available shape (.shp) files (map layer with attributes).  In most cases, but not all, there is only one .shp file in each folder. Take a look at the map and its table of data (attributes).

Note: the two folders of orthophotos contain very large image files.  If ArcMap is slowing down after adding these layers, feel free to remove the layers from your ArcMap project file after you take a look at them.  Please, in your blog entry, document what an orthophoto is.

• In some cases you can easily figure out what the data is – hydro, for example (rivers, etc.).  In other cases you will have to refer to the metadata (data about data) for the Delaware Data at the Delaware County GIS web site (DALIS).  Once there, select Files to Download. Fill in the info at the bottom, check the box, and hit Download Data.
• A page of available datasets appears.  Don’t download any data (that has been done for you) but do check out the metadata link for each data set.  This should clear up basic questions about the data.

Ask me if you are having any problems!

OrthoPhoto Fix

A quick fix should make the orthophotos (air images) align properly with the rest of the Delaware GIS data:

The problem is that the units of measurement for the orthophotos is in meters, and the units of measurement for the other Delaware GIS data is feet. So change the units of the orthophoto files to feet and the problem should go away:

1. open ArcMap and create a new empty project

2. add the road centerlines: Delaware Data/Delaware Roads folder

3. from the Tools menu select ArcCatalog

4. select the Delaware Data folder in the left window in ArcCatalog

5. double click on the OrthophotoAp2006 folder in the right window in ArcCatalog

6. click once on Delaware_2006_Half-ft_North.sid in the right window in ArcCatalog

7. from the File menu select Properties…

8. a window will pop up: Raster Dataset Properties

9. scroll down to Spatial Reference and click on the Edit button

10. click the Modify button on the window that opens

11. in the Linear Unit box select Foot. Hit OK, then OK, then OK to get back to ArcCatalog.

12. repeat with the Delaware_2006_Half-ft_North.sid file (repeat steps 6 to 11).

Add the orthophoto to the ArcMap file with the road center line. The orthophoto should align properly.

I will put a lower resolution orthophoto on the computers, as the two high res files (north and south) take a long time to open on our older, white computers. When that is complete, you will have to go through the same process as above to change the units from meters to feet. I will let you know when that happens.

Delaware GIS Data Exercise

Each student will create an ArcMap map with the following Delaware GIS data layers & describe (sentence or two) all data layers except those marked ‘ignore.’ (the ignore folders have data that is not relevant, or newer versions of the data are in other folders)

In essence, you are creating a very brief set of metadata (data about data) for all the available layers of information. There may be several shape files (.shp) in these folders, make sure to review all of them.

Keep your brain engaged: how might some of these layers help our course project?

Put your metadata comments in a blog posting.

You will use some of this data for your take-home mid term exam.

DUE: Mon March 3.

Delaware GIS Data Metadata is here.

If any data folders are missing please talk to your instructor.

Delaware GIS Data Layers:

Annexations
Census-Block
Census-BlockGroup
Census-Tract
City_Trails (ignore)
Del_Co_bike_green (ignore)
Delaware_Address_Pts
Delaware_Buildings_1
Delaware_Buildings_2
Delaware_Cemeteries
Delaware_Conversion (for data conversion demo only)
Delaware_DEM (ignore)
Delaware_Farmlots
Delaware_GolfCourse
Delaware_Municipalities
Delaware_Parcels
Delaware_Parks
Delaware_PostOffice
Delaware_Schools
Delaware_Subdivisions
Delaware_Trails (ignore)
Farmlot (ignore)
Floodplains
GPS (ignore)
Historical-Archeological
Historical-Delaware
Historical-National
Hydro-detail
Master-point
Mental Maps (ignore)
Natural Heritage ODNR
Old Dalis Data (ignore)
OrthophotoAp2006
Parcels (ignore)
Precincts
Public Land Survey System
RailRoad
Road Centerline (ignore)
Road Rightofway (ignore)
School
Soils
Subdivisions (ignore)
Tax Districts (ignore)
Topography
Townships_historical
TWP (ignore)
Traffic-MORPSE
Utilities-Sewer (ignore)
Utilities-Water (ignore)
Watersheds-ODNR
Wetlands
Woodland-ODNR
Zip2004
Zoning