Import/Export and Raster Data Processing
To import data into ArcGIS
To introduce Spatial Analyst of ArcGIS.
To illustrate the characteristics of raster data using the US Geological Survey’s DEMs.
To become familiar with working environment of ArcGIS and to process raster data using ArcGIS.
Getting Started: Today, we will import Digital Elevation Models (DEMs) using ArcGIS software and apply some processing techniques to the data. There are many ways to import DEM data into ArcGIS. DEM data can be stored on a tape (8mm, 9track, or 4mm), on a floppy disk, on a CD-ROM/DVD, Blue-ray or as a file. Today we will import data from files that are already on the system. Let’s have some fun!
1. Login to your account.
2. Map your network “K” drive if it is not available. First check your directories if a “K” drive exists (if you checked the “reconnect at logon” dialog box, then your K drive is reconnected each time you logon to your account). If there is no K drive mapped, please use the followin in your windows Explorer (not Internet Explorer!) to map K drive:
Type \\strabo in “Address” window of your Windows Explorer. Then right click on “GSC45” directory and select “Map Network Drive” and select K as the drive letter (check the “reconnect at logon” dialog box). We will use this “K” drive for the lab assignments this semester.
3. You should have a folder (your last name_) in K:\GSC_521_01\class\
(i.e., K:\GSC_521_01\class\cetin). Go to K:\GSC_521_01\labs\ folder and copy Lab2 in this folder into your folder.
4. Run ArcMap: (if there is not ArcMap 10.3 icon on your desktop, go to All Programs and select ArcGIS -> ArcMap 10.3.1)
5. Go to Customize menu and select Extensions; Make sure that Spatial Analyst has been checked.
6. Go to K:\GSC_521_01\Class\Your_folder\lab2 directory and import the three DEM files (file1.dem, file2.dem, file3.dem); I suggest you find out the quad names first (see Question 1) to name the new GRID coverages in ArcGIS. Let’s use our brains!
Go to the “Geoprocessing” menu and click the red “Arc Toolbox” (or select the red icon,
for Arc Toolbox; it might take several seconds to pop-up); select “Conversion Tools” and go to “To Raster” and select “DEM to Raster” to import USGS DEMs in Lab2 folder. Make sure to select Integer for the option (not float).
Please answer the following questions:
Question 1: What are the actual names of the quadrangles for the files (file1, file2, and file3). Can you name them? (yes, you can! and please do so!)
file1:__ __________________ file2:____ ________________ file3:____ ________________
5. Display the DEMs and use gray levels.
Question 2: Which area do you think has the lowest elevation in the region? (assuming darker areas are lower)
Go to Spatial Analyst Tools of ArcToolbox menu -> Neighborhood and select “Filter”
Please use Low and High Filters Examine the changes in the image.
Question 3: a) What did the Low filter do? :________________________________________
Note: make sure to select the original grid coverage, such as Hamlin, for input)
b) What did the High filter do? :________________________________________
Now try Focal Statistics and select “Mean”
Question 4: Compare the Mean and Low images. Describe the two datasets (Are they similar?).
6. Map units are in meters
Question 5: What is the elevation of Kentucky Lake (in meters)?
7. From “Surface” menu of Arctoolbox use Slope to create a slope map.
Question 6: What is the slope of the Lake? :____________________
Question 7: What is the length of the Lake (from the southern end to northern end) in the imaged area (in meters) using the three DEMs together?
8. From “Surface” menu use Aspect to create an aspect map.
Question 8: a) What is the aspect value of the Lake? :____________________
b) What does it mean?
9. From “Surface” menu use Hillshade to create a shaded relief map.
Question 9: What do the areas with dark color (black) represent? :____________________
10. Open Attribute table (right click over the name of a DEM and select OpenAttribute Table) of one of the DEMs and select 109 value from the table and look at the DEM image.
Question 10: What do the areas with cyan color represent? :____________________
Save your project as klakedem in your Lab2 directory.
Close the ArcMap session and please Logout (use “Start” menu at the lower left corner to logout)