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Tutorial 1 - Data Sources & Building a GeoDatabase

Objectives:

• become familiar with data sets available at Broward County GIS Data Center http://gis.broward.org/GISData.htm
• learn to download and import data sets
• learn to clip data sets for specific areas
• learn to save data sets for future use

Visit Broward County GIS Data

Broward County GIS Data Center (BCGDC) host a data repository containing a number of GIS data sets. The web site is http://gis.broward.org/GISData.htm (a new browser window/tab will be opened). For the rest of this exercise, we will refer to the site simply as BCGDC. You will most likely be using data from this repository for the rest of the semester.

Click the link above and Open a new web browser and navigate to BCGDC.

BCGDC provides mostly vector data (e.g. point, line, or polygon) in the ESRI shapefile format. They are also zipped. You need to unzip these files before use them in ArcGIS.

They also provide links to some of the raster data (e.g. orthoimagery, digital elevation models, etc) offered by other agencies.

Viewing metadata

To view metadata (a description of the data set), click the Desceiption link next to each of the data links.

The metadata are very important because they (should) tell you all about the data source, e.g., what it is, where it came from, what the fields and values in the attribute tables mean. For certain data sets, the metadata files are not linked directly, it takes a few clicks to find metadata on the data source you are interested in. Also, different data sets are linked to different versions of the metadata records system.

Hover the cursor over the Desceiption link for the data set City Boundaries.

Click the link for this data set. This will open up another window or tab showing you all information currently available about this partcular data set.

You can find five tabs on the top of the page right below the title of the data set. the first one "Description" has information about the data source, such as what it is, where it came from, when it was created. The second one "Spatial" contains information about this data set's spatial reference (i.e., coordinate systems used for the data set). The third one "Data Structure" overviews some important information of all attributes in the data set.

Click the link "Attributes of PSD.Cities", a list of short descriptions of all attribute in the data set can be found here. Although not very detailed.

Extra notes:
Metadata may be presented in different ways in other geospatial data sources (e.g., online GIS data warehouses or data clearinghouses). Some may be presented with different versions of the GeoGuide. They may look like the following:

The metadata system may get rather clunky to work through, but becoming familiar with the data is important. If you need to know what the values in your data's attribute tables represent, metadata are critical.

Download Data Sets

In this part of the exercise we will download a few data sets from BCGDC, which may be commonly used in this class.

We will initially save the data on the computer's hard drive. After downloading and unzipping or importing we will clip the data to the city boundary (city limit) for City of Oakland PRK and then save them on your USB drive or the shared server space in H: server.

Create the directory on Desktop. Name it gisdata.

From BCGDC, download shapefiles for these data sets and save in Desktop\gisdata. Note the most efficient way to save the data sets is to right-click the link and select Save Target As (note -- if you're using Firefox instead of Internet Explorer, select Save Link As) from the pop-up menu, then navigate to the directory where you want to download data. If you are using Google Chrome, just click the link, all these zipped files will be downloaded to your "Downland" folder in under Windows directory.

• City Boundaries
• County Boundary (entire area)
  
• 2010 Census Tracts
• Streets
  

Unzip Data Sets

Before anything can be done with the files in the GIS, they must be unzipped.

Find all these zipped files in your file directory, double-click them. You should see all the files that are contained inside the zipped folders. Click Extract all files, then find your Desktop\gisdata directory and save these file to it.

Do the same for other zipped files in the Desktop\gisdata directory.

Create Geodatabase and Clip datasets

We will focus on the area within City of Oakland park Boundary, so the data sets for BCGDC need to be clipped. Rather than clipping like a cookie cutter, we will create new datasets that consist only of features that overlap with the city limit. Start by adding all the BCGDC data to a data frame in ArcMap.

1. Open ArcMap (Start > Programs > ArcGIS > ArcMap 10.4.1).
   
   
2. Open ArcCatalog by going into Start > Programs > ArcGIS > ArcCatalog 10.4.1), and navigate to Desktop\gisdata (make a connection to this directory first). Note that the Desktop is actually stored in C:\Documents and Settings\user\Desktop (where user is the currently logged-in user, most likely 49er on the UNCC computers).
   
   
3. Select all shapefiles in ArcCatalog and drag them into the ArcMap map display.
   
   
4. Back in ArcCatalog, move the mouse over the gisdata folder and then right-click,
   1. Select File > New > File Geodatabase from the menu. Name the geodatabase file project_data. The geodatabase will store all of the clipped data sets for your future use.
      
      
      
      
   2. Right-click the project_data geodatabase.
   3. From the menu select New > Feature Dataset... Name the new feature dataset oaklandpark. A feature dataset is a collection of related feature classes (a feature class is a data source for a single layer). This feature dataset will store the clipped City of Oakland Park Data.
      
      
      
      
   4. Click the Next button to edit the feature dataset's Coordinate System definition. All feature classes within a feature dataset must have the same coordinate system.
   5. Click Import. Navigate to where all the unzipped files are, and select Cities.shp as the dataset you will copy coordinate system information from. This step is important, because if the improper coordinate system is specified, the data in the feature dataset may become corrupted. Notice that currently we use NAD_1983_HARN_StatePlane_Florida_East_FIPS_0901_Feet as the coordinate system.
      
      
      
      
   6. Click Next to edit the feature dataset's Coordinate System definition for Z coordinates. Since none of the data layer we have in the directory has this information, so we have to define it from scratch. In the box below, click the small + sign in front of Vertical Coordinate Systems, then North America, then choose NAD 1983 to make it consistent with the horizontal coordinate systems you picked in the previous step.
      
      
   7. On the final page, leave all numbers as default, click Finish to complete all settings.
   8. Close ArcCatalog to avoid file sharing problems between ArcMap and ArcCatalog. Don't forget to do this... very important!
   9. Now we have an empty geodatabse, we will then add layers in it.
      
      
5. In ArcMap, select Selection > Select by Attributes from the menu.
   1. In the Layer control select Cities.
   2. Double-click "CITYNAME" (the attribute representing which side of the UGA line each polygon is on).
   3. Click the equal sign.
   4. Click the Get Unique Values button.
   5. Double-click 'OAKLAND PARK'. Your query should look as below:
      
      
      
      
   6. Click OK. This will select the polygon from the Cities layer that is inside the Oakland Park city limit. Turn off all layers except Cities. You should see your selected polygon in cyan.
      
      
      
      
6. Now this will be used to select features from other layers that overlap with the Oakland Park city limit. From the menu select Selection > Select by Location.
   1. Click the checkboxes for ALL the layers in the list labeled "Target layer(s)" EXCEPT for Cities.
   2. Specify that you want features that intersect the features in Cities.
   3. Make sure to check to Use selected features from Cities.
   4. Click OK. A dialog will display. After awhile all the overlapping features will be selected in each other layer.
      
      
      
   
   
   
   
7. Right click on the first layer in the Table of Contents, and select Data > Export Data. Export the Selected features (this will export only those features that overlap the city limit), using the third selection for the output coordinate system (this will assure that all the data sets in the feature dataset have the same coordinate system definition; note that this selection may not be available until you complete step #8 below).
   
   
   
   
   
8. Click the folder button , be sure that "Save as type:" at the bottom of the dialog window is set to look for geodatabases, and navigate to the oaklandpark feature dataset. Enter the same name for the new feature class as the shapefile you're exporting.
   
   
   
   Click Save. Then click OK. An indicator will display progress of conversion.
   
9. When prompted, add the new data set to the map. Only do this for the first data set, just to verify that your output data set is OK.
   
   
   
   
10. Repeat this process with each layer, including Cities. You may find it saves time to edit the name of the output dataset (as illustrated below) rather than navigating using the folder icon and then typing.
    
    
    
    

Getting Census Data

For this exercise, you will find using Firefox or Chrome is much more problem-free than using Windows IE. IE's pop-up blocker for some reason prevents us from downloading census tables proeprly.

Please use Chrome to work on this exercise.

First go to: http://factfinder.census.gov/faces/nav/jsf/pages/index.xhtml
Select "Advanced Search" then click"SHOW ME ALL".

Click Geographies to set the geographic limit and units for which you want to get the census data out.

First click Census Tract from the Select a Geographic Type list in the window. Then click Within State from the list. Then choose Florida from the list to refine your filter. You have just added another geography filter. Now click Within County from the list and select Broward from the list. You added another geography filter to further narrow down the geographic extent for viewing/downloading census data. Then Click All Census Tracts within Broward County in the box then hit the button Add to Your Selections.

Then click Race and Ethnic Groups, choose Race/Ethnicity of Individual from the list. After that, clicking the X button on the top-right corner of the "Select Race and Ethnic Groups" window to close it.

You will see many census tables are available under this category. typing in "P1" in the search box, then click GO, as shown below in the image.

You should now see P1 on the list. Check the box next to it.

Now you can start to download this particular census topic from the website. Click Download button (both on the top and bottom of the table).

Click OK when see the message below:

Then in the next message box, click DOWNLOAD.

Extract all the files in the zip file to your gisdata directory. There will be two Excel files listed as being zipped in the file.
Open the file that ends with "...with_ann".

Make note of what the variables represent, and eliminate the second row of the Excel file (with all of the descriptions). You have to adjust the format for the second field, GEO.id2, to make it consistent with what is typically used by GIS data. Please see tutorial 1.5 for more information.

You may want to save your file as an Excel 97-2003 Workbook (.xls).

Re-open ArcCatalog, connect to your gisdata directory, click the small + in front of the excel file DEC_10_PL_P1_with_ann.xls, you should be able to see the worksheet DEC_10_PL_P1_with_ann$, this is where your census data is stored. Right-click this worksheet, then choose Export > To Geodatabase (single)... This will be used to copy your census data table into the geodatabase.

For the Output Geodatabase, click the folder icon and navigate to the project_data.gdb geodatabase you created. Do NOT double-click the geodatabase, just select it and click Add. Click OK in the tool dialog.

Name your output table, such as census. Click OK to finalize the process.

Now you can double-click your geodatabase in the directory tree, and you should be able to see your census table there in the geodatabase.

Delete all of the zipped files you downloaded. Then copy your file geodatabase to your USB drive or you can create a temporary directory in H: server and store all your files there.

Exercise 1 - Building a GeoDatabase

The deliverable:

Your assignment is to complete the following task:

Please go ahead to download more shapefiles from BCGDC and add them into your project_data.gdb geodatabase.

You do not need to turn in anything, but be sure to complete this task by Sep 15, 5:00pm.

prepared by Ming-Chun Lee, 09/05/2016