Lab 6: Importing Data into a Geodatabase
Overview & Background Information
In the first lab, we asked you to explore the availability of GIS data on the Internet. Your task was to identify data sets that could be used in support of specific research problems or questions. This week, you will practice importing the data that you identified in the first lab, or new data sets that you have identified since then into a geodatabase. This geodatabase can then be used for your research or project. Although it is possible to perform many operations and analyses using data in the format you acquire them in, converting to a geodatabase is a skill that will help you organize your project data and make it more universally useful within ArcGIS. We want you to include at least three thematic layers into your map.
Learning Objectives:
To understand the organization of geodatabases To understand the process of importing data into a geodatabase To revisit the procedures for projecting data and map creation for delivery of final products
To be submitted:
1. (15 pts) A write-up answering the questions at the end of the lab, including a screenshot of your final geodatabase in ArcCatalog, expanded so all the feature datasets and feature classes can be seen. 2. (5 pts) A thematic map of your downloaded data that communicates a particular message to a general audience.
Procedure:
1. Download and standardize your data
Locate the data layers you want to import; these could be the ones you explored to answer your own research question in Lab 1 or new data you identify as your questions or ability to find data have improved. Download and unzip them (if necessary) to your Lab06 folder. If you are unable to download your data from Lab 1 you must find spatial data that you can use. See lecture Powerpoints for spatial data sources. Be sure to form a question before acquiring your data.
Unzipping data
Much of the GIS data that is available for download comes compressed in a .zip file (like our lab data). However, you may also encounter RAR (.rar) files and gzip (.gz) files. These are also compressed files. Like .zip files, they may be unzipped using WinZip or 7-Zip.
**Note: If you downloaded any TIGER census files, you must first unzip the file that you downloaded, then open the folder in Windows Explorer. Navigate through all the nested folders, and you will reach another zip file that contains your data. Be sure to unzip this folder before you try to import any data.**
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Supported Data
After you have unzipped your data, you will be able to see the format in which it is stored. We provide instructions for how to import the following data formats into geodatabases. Other file types may be more complicated to import or contain data that are not simply translatable into geodatabases. To simplify your tasks, if you find data files that are not among those listed here, we suggest that you look for files that are. Ask your GSI if you are unsure about a file type.
Vector data model Raster data model ♦ Shapefiles (.shp) ♦ ARC/INFO interchange files (.e00) (containing ♦ Coverages ESRI GRID rasters) ♦ ARC/INFO interchange files (.e00) ♦ ERDAS IMAGINE rasters (.img) (containing coverage files) ♦ MrSID rasters (.sid) ♦ JPEG rasters (.jpg) ♦ JPEG 2000 rasters (.jp2) ♦ ESRI Band Interleaved by Line rasters (.bil) ♦ Tagged Image File Format (TIFF) rasters (.tif) ♦ GeoTIFF rasters (.tif) ♦ Graphic Interchange Format (GIF) rasters (.gif) ♦ ESRI GRID rasters ♦ Portable Network Graphics rasters (.png)
If you downloaded any files ending with the .e00 extension, follow these next steps. If not, you may skip to the next section.
Converting .e00 files
Files with the extension .e00 are ARC/INFO interchange files. These files are created to transport coverages as well ESRI GRID and TIN files across different networks and between different types of computers. They need to be converted back to coverages before they can be used.
♦ In ArcCatalog, open the toolbox and go to Conversion tools │ To Coverage │ Import from E00. ♦ A new window will open. Click the browse folder to navigate to your Input interchange file. Then click the browse folder to set an Output folder. Finally, in the Output name field, provide a proper name for your file. You will not be able to save it in your geodatabase just yet. Click Save and OK to convert the file.
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Standardizing projections
Before you add your files to a feature dataset, you must make sure they are all in the same projection. Feature classes cannot be stored within the same feature dataset if they do not share a projection. If you found your data from different sources, it is likely that the data sets will be in different coordinate systems with different projections. If you got all your data from the same source, it is still a good idea to verify that the projections match. Follow the steps in Lab 4 to check for the projection of your data and refer to your answer for Question 5 in Lab 4 to determine what the ideal projection for your data should be. If you need to change the projection, please refer to the steps indicated in Lab 4. Remember that you can import projections from an existing file in addition to selecting them from a list. This ensures that the layer you are working with has exactly the same projection as the layer whose projection you import.
2. Create an empty geodatabase
Follow the steps you learned in Lab 05 to create an empty geodatabase, and a feature dataset within it that has the projection set to the projection of the data. As with reprojecting data, you can select the projection from a list or import one from an existing dataset. You do not need to define a vertical coordinate system. You may create as many feature datasets as you deem appropriate. Just ensure that the projection you set for the dataset matches the projection of the layers that will go into it.
3. Import data into your geodatabase
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Now you will import your downloaded data into your geodatabase. Double-check to make sure your data are all in the same projection before proceeding. This section includes instructions for importing the many types of files you may have downloaded.
To import a shapefile (including TIGER data):
♦ Within ArcCatalog, right-click on your feature dataset and go to Import | Feature Class (single). ♦ Click on browse folder next to the Input Features box and navigate to your shapefile. Click Add. ♦ In the Output Feature Class box, type a name you want to give your feature class. ♦ Click OK. When the process is complete, click Close in the status window.
To import a coverage:
♦ Importing a coverage is similar to importing a shapefile. Right-click on your feature dataset and go to Import/ Feature Class (single). ♦ Click on the browse folder next to the Input Features box and navigate to your coverage. Double click on it to see the arcs, polygons, and tics it contains. Select the feature you’d like to import and click Add. ♦ In the Output Feature Class box, type a name for your feature data class. ♦ Click OK. When the process is complete, click Close in the status window.
To import a raster dataset (.img, .bil, .sid, .tif, GRID, GeoTIFF, .gif, jpeg2000):
♦ Right-click on your geodatabase (not your feature dataset) and go to Import / Raster Datasets… ♦ In the new window, in the Input Raster field click on the to browse to your directory and select the raster data ♦ In the Output Geodatabase field, the software will automatically be set to the geodatabase you created. Click OK. ♦ When the import operation is complete, click Close in the status window.
Some of you might need to perform some extra tasks (e.g. if you have a table with information that needs to be joined to a feature class). Instructions in Appendix I will guide you in how to join tables and how to clip data to your extent of interest (vector and raster).
4. Create a thematic map
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Now that you have your data organized into a geodatabase, add it to a map document to create a thematic map that helps answer your research question. Be sure to include the projection used for your map along with source data.
QUESTIONS TO ANSWER:
Question 1 (5 points): Give some reasons why you might want to have multiple feature datasets in your geodatabase. That is, what are the potential advantages to storing feature classes in different feature datasets of a geodatabase? Similarly, under what circumstances would it make sense to start a new geodatabase?
Question 2 (5 points): When you have imported all of your data, expand your geodatabase and all of its feature datasets in the ArcCatalog file tree by clicking the (+) buttons next to them. Make sure all your imported files are visible. Take a screen shot of your expanded geodatabase by pressing ALT+Print Screen, or use the snipping tool, and paste this image into your lab write-up.
Question 3 (Map Reasoning) (5 points): What are you trying to show in your map? What do you want the viewer to get out of it, and how did you use different design elements to communicate your message? How does your map help you answer your research question? What other data do you wish you had?
Map (5 points): Create a thematic map of your data, including at least three different layers and all essential map elements.
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