Introduction to Geographic Information Systems

ERE 450/550

Lab Exercise 4

Lab due on Monday November 13 to TA’s in 149 Baker Lab by 8pm

 

Purpose

The purpose of this lab exercise is to address the following questions and issues raised in the scenario provided in Lab 2.

 

Questions/Issues:

How many people are near or in flood zones?

Home ownership and population density near or in flood zones?

Zip Codes near or in flood zones?

Watersheds of the flood zones?

Dams upstream of flood zones?  

Transportation and Armory locations within City of Syracuse?

Digitize Meadowbrook and its flood retention basin

Edit Armoy and Dams

 

Data Sets (From PROJDATAEG):

syrarmory (in Trans Folder), syrroads (in Trans Folder), ono_u_col_index03 (in Image folder) and related images, onolshydnet (in Hydro folder), onolshydsur (in Hydro folder), onondams (in Hydro folder), syrfloodgcs27 (in Hydro folder), syrblocksgcs83 (in Census folder), onowtlndsutm83 (in Hydro folder), onowtrshdsutm83 (in Hydro folder), syrzipgcs83 (in Census folder), syrroads (in Trans folder), syrrrgcs83 (in Trans folder), Syracuse (in Census Folder).

 

Expected Output:

Map of blocks (symbolizing population) that intersect defined flood zones with Interstates, RR’s, Armories, Streams, Ponds/Lakes, Wetlands, and Dams mapped (all bounded by city boundary).

 

Answer to questions on answer sheet (provided)

 

Spatial Model (blank answer sheet provided)

 

Okay, you’ve come a long way and you still have a ways to go. This lab has more concise direction with the expectation that you’ve been keeping a good notebook and starting to get the “gist” of ESRI software use. Please read over this exercise BEFORE doing it.  If there are processes that you cannot do without more specific direction; get your notebook and labs 1-3 out to figure out how to do the process.  Also, see the web pages for more help. Make sure your data is going where you want it to (outputs getting saved into the correct folder). Are you saving your project routinely? Use Michelle’s power point to help you do your map composition. Finally, do the spatial model as (or even before) you do the exercise….it’s a lot easier that way.

Data Management

 

Folder Work and Managing Input Data (ArcCatalog)

  1. Create a new folder on the computer hard drive C named FLOOD.

 

Note: To minimize storage requirements, you will only copy data sets that you will manipulate. However, you will have to be able to access my folder to do this project. If you want to do this work in a place where you cannot access the folder, you will have to copy the datasets you use from my folders. Remember that saving a project DOES NOT save the data with it; it only saves the paths to that data.

 

  1. Copy the following data sets into C:\FLOOD: syrarmory, onolshydnet, onolshydsur, onondams, syrfloodgcs27, and syrblocksgcs83 (See page one for locations).

 

Edit Armories (point)

  1. Start ArcMap and add layers (data) syrarmory, syrroads, and ono_u_col_index03 (location from page 1). Did you remember how to add data to the data view in ArcMap? Are you naming and saving the project?
  2. In the TOC, make sure armory is on top, then roads, and then the index.
  3. Add the Editor Toolbar from View Menu\Toolbars – Check (click) it “on.”
  4. From the Selection menu choose Select by Attributes and from the Layer drop down menu select syrroads.
  5. In the Select by Attributes window select Create a New Selection from the Method drop down menu.
  6. Double Click on “FENAME”, click once on = , and click on Get Unique Values. Find and double click on ‘Genesee’ so that it looks like: "FENAME" = 'Genesee' in the query window (the window at the bottom).
  7. Click Apply and DON’T close the Select by Attributes Window. You should see a blue line which designates the selection of Genesee Street.
  8. Go back to Select by Attributes Window, clear the current expression (clear button), change Method to Select from Current Selection and query as you did above for the following: "FEDIRP" = 'E'. Apply. Again, do not close the Select by Attributes window. The blue line gets shorter because you just reduced your selection to E. Genesee St. By the way, this method is another way to do the Boolean AND operation.  You’ll see an example of using this method later.
  9. Zoom into the point south of the selected road. Use the Identify tool to select the syrarmory point (click on the point) and read the record (you will have to use the drop down menu in the Identify Results window to select the syrarmory layer first). What’s the address of the armory? Is the current position of the Armory point anywhere near the selected street (blue line)?
  10. Go back to Select by Attributes Window for syrroads and use Select from current Selection to do the following query: "FRADDR" > 1000 (type in 1000 in the query window). Apply and don’t close the window.
  11. Again use Select from current Selection for the following query:  "TOADDR" < 1100. Apply, and now you may close the Select by Attributes window.
  12. Use Zoom to Selected Features from the Selection Menu
  13. Use the Identify tool, set the layer in the Identify Results window to the ortho index (ono_u_col_index03), click near the selected street. What is the FILENAME that is in the identify results window?
  14. Find and add that image to ArcMap from the PROJDATAEG\Image folder. You want the raster dataset and NOT the text file.  This is difficult because the file names are by x and y UTM Zone 18N coordinates, so be deliberate in your selection. I used my open identify results window to find the data set.
  15. Right click on color symbol for the ortho index and select no color. You should see the orthophoto you just added. The armory is a big building near the middle of the block on the north side of the street (with lots of roof repair evident and a big parking lot to the north. You can use the pan tool to look around.
  16. From the drop down menu on the Editor toolbar (Editor button) find and select Start Editing. Make sure the folder is your FLOOD folder (select it in the upper window) and click OK. If you get a warning about layers in different coordinate systems, that’s okay for what we’re doing; go ahead and click the Start Editing button.
  17. In the Editor toolbar select Create New Feature for Task, and the Target is syrarmory.
  18. Activate (click on) the “sketch” tool (Pencil). You’ll get the cross hairs when you pass your cursor over the image. Left click once on the armory in the image to create a blue dot.                   
  19. Open the syrarmory attribute table. A new record was added and it should be blue (selected – which corresponds to your selected-or newly added point).                 
  20. Copy the information from the record above into the new record below by using copy and paste (right clicking) or by typing it in so that the information is repeated for both records.
  21. After you get that done, go to the Editor toolbar and select Save Edits (drop down).
  22. Zoom out until you see the erroneous point for armories. (The one to the south and east of the one you just added)
  23. Change the tool from sketch tool to edit tool on the Editor toolbar by clicking on the arrowhead symbol left of the pencil. Select the erroneous point (click on it). Your newly added point should not be selected anymore and the bad one should turn blue. Press delete on the keyboard.  The bad one should disappear leaving your corrected one.
  24. Go to the Editor toolbar and select Stop Editing, and yes you want to save your edits.
  25. If syrarmory is still GCS_Assumed_Geographic_1, define the projection (NOT PROJECT) of syrarmory to GCS_North_American_1983. (In addition to the spatial tab in the metadata in ArcCatalog, you can also check the projection by right clicking on the layer, choosing properties, and checking out the Source tab.)
  26. Just in case go to the Selection menu select Clear selected features. If it’s not available, that’s okay too. Keep going. Get to know this particular command. Many of the features of ArcMap only work on selected records, so I am in the habit of constantly clearing the selected features (or checking the same) before I run GIS operations.  You should notice that there are no more “selected” features appearing in the data view of ArcMap.

 

 

Edit Large Scale Hydrography Network (arcs)

Note: The following process is tricky, read this over before you do it and be prepared.

  1. Add the onolshydnet layer to ArcMap
  2. Use Select by Attributes (create new selection) on syrroads to select Meadowbrook Road ("FENAME" = 'Meadowbrook'). Apply, and you may close the window.
  3. Use the identify tool with the ortho index to get the filenames of the images you’ll need.  You will need up to 9 of them to see the brook and surrounding area, but if you can do it with 6 that’s okay too.  Add those images to ArcMap (the same way you did it before). Again, I used my identify results window and just did one at a time. Be careful you don’t add the color infrared images by accident.
  4. Zoom to the east end of the selected line and the western endpoint of the syrlshydnet (streams) line. If you want, add the image where the stream line ends, but what you have is good enough for our purposes.
  5. Start editing (your FLOOD folder) from the Editor toolbar with the task, Create New Feature and target syrlshydnet. (Again if you get that warning, start editing and keep going).
  6. From the Editor toolbar drop down menu select Snapping. A window will open. Check the box for the end point of sylshydnet.
  7. Zoom in so that you can see the intersection (and all the construction equipment) The brook is under your selected line for Meadowbrook Road. Zoom in to about 1:2,000 (you can see and even set the scale in the box on the standard toolbar at the top of ArcMap and to right of add data button).
  8. Activate the Sketch tool. You’ll get the cross hairs.  Left click ONCE very close or on the end point of the network hydrography so that it snaps (connects) to that existing line.  Start tracing a line over the brook shown on the image using one left-click for each vertex (where the line curves) Be careful DON’T DOUBLE CLICK. When you run out of room, use the pan tool (the hand) to move to the west and keep digitizing (clicking). After you pan, the sketch tool should reactivate, but you can always make sure by activating that tool again (clicking once on that icon). Basically, the brook runs along the selected line.
  9. Do the best you can where the stream runs underground.  If you get in trouble, you can always “undo” using the undo button or CTRL-Z on the keyboard.
  10. Do the best you can to digitize the line through the retention basin (you can almost see where the main flow is). Finish the digitizing where the stream ends at the edge of the SU athletic fields (near Manley Field House) by double clicking. The new line you just digitized should turn blue.
  11. Select Stop Editing and Save your edits.

 

Edit Large Scale Hydrography Surface (polygons)

  1. Add onolshydsur to ArcMap
  2. Zoom in to the Meadowbrook retention basin (the pond you traced through before).
  3. Use the same process above to digitize the retention basin as a polygon (different target this time, onolshydsur, but it’s still create a new feature). Don’t activate snapping this time. Digitize the polygon at between 1:2000 and 1:4000 scale. (It doesn’t ultimately matter because you’re adding this feature to a 1:24000 scale data set).
  4. For polygons, digitize the vertices the same way (one left-click per vertex). But be a little careful, the feature automatically has an enclosed area that you’ll see “open up” as you digitize the vertices; you’ll see the shape of the polygon change as you digitize around the edge of the retention basin.
  5. As before, double click when you’re done, stop editing, and save your edits.

 

Edit Dams (point)

  1. Add onondams to ArcMap
  2. Zoom in to the retention basin and use the same methods as above to edit onondams and add one point where the retention basin flows into the brook (north and a little west of the end of pond – near the intersection of Meadowbrook and Broad – if you aren’t sure about where you are in the image use the identify tool with the roads layer) There are actually a couple control gates that you may or may not be able to see in between the two lanes of Meadowbrook Road. Getting the new point close enough is okay for our purposes.

 

Prepare Flood Zones

  1. Add syrfloodgcs27 to ArcMap (you may get a warning about different coordinate systems, click ok, you’ll fix that)
  2. Project syrfloodgcs27 into NAD 1983 UTM Zone 18N and name it syrfldutm83 (don’t forget to do the NADCON part because you’re transforming from the NAD27 to the NAD83 datum).
  3. Add syrblocksgcs83 to ArcMap and also project it into the same coordinate system used above (no NADCON this time; it’s already using the NAD83 datum). Name it syrblksutm83.
  4. Zoom out using the layer syrroads (right click on the layer in the TOC and select zoom to layer).

 

NOTE: Finding metadata on the flood zones was a pain in the butt this time. I had to google to get information about what the field codes meant….the attached metadata had nothing! Below, I’m going to show you another way to select records to create a new layer.

 

  1. Use the Select tool from ArcToolbox (Analysis Tools\Extract).
  2. This time we’re going to use Boolean logic for the selection, instead of what you did before (we actually could have used a similar method-using AND-in the query window to do the E.Genesee St. selection). The input is syrfldutm83, name the output syrfldznutm83. The equation for selection (in the expression window) is as follows:

            "ZONE" = 'A' OR "ZONE" = 'AE' OR "ZONE" = 'AH' OR "ZONE" = 'X500'.

 

You may have some trouble with syntax (the relative positions of the characters in the equation), so be careful and deliberate when typing in the equation. The other way to do this query is to simply use ZONE <> x, but I wanted you to see the Boolean Or operation.

 

  1. For your new dataset (syrfldznutm83) add the field FLDZN by either opening the table and using those options, or by trying the tool from ArcToolbox (Data Management Tools\Fields). Make the new field a short integer (SHORT) field with a precision of 4.
  2. Calculate the new field to equal 1. Again you can use the options from the attribute table or the tool Calculate in ArcToolbox (Data Management Tools\Fields).
  3. Find and activate the Dissolve Tool from ArcToolbox (Data Management Tools/ Generalization). The input is syrfldznutm83, the field is FLDZN (check it), the output is named whatever you want (I let it default, and I’m using my notebook to write down the name).  Make sure the Multipart option is checked (at the bottom of the window). Click OK.
  4. Find and activate the Calculate Areas script (same method as selecting a tool) from ArcToolbox (Spatial Statistics Tools\Utilities). Use the file you created in the step above as input and name the output fldznwarea. This is one of those places you really want to check in which folder it’s getting saved.

 

NOTE: It will calculate the area for whatever the projected coordinate system units are. So in what units is area for this data set? You’ll need to know that later to calculate population density per square mile.

 

Analysis

 

Overlay Floodzones and Census Blocks

  1. Find and activate the Intersect tool from ArcToolbox (Analysis Tools\Overlay)
  2. Take a look at the helpful help diagrams (Show help if you can’t see it)
  3. The inputs (for this intersect, order doesn’t matter) are fldznwarea and syrblksutm83, name the output whatever you want. Leave the rest of the options alone and click ok
  4. Open the attribute table of the intersect layer, and add a new field named TOTAL (short integer, 4 units precision) and calculate the new field equal to one.
  5. Do a summary table on the TOTAL field (Summarize) and sum (check the option for sum) for housing units (not households), renter occupied units, owner occupied units, and population. (Note that you have to figure out what the field names mean, but it’s really not that bad…and you can always check the metadata from the web sources.)
  6. You may name the summary table what you wish, or let it default, but remember that name for future processes (mine was Sum_Output.dbf).
  7. Make sure your table is added to ArcMap. If you don’t see it, click on the source tab on the bottom of the TOC. If it still isn’t there, add it.
  8. Join the summary table that you made to the fldznwarea using the FLDZN and TOTAL fields.  Be careful of the order, activate Join from the fldznwarea layer. If it asks you if you want to index, click Yes. Indexing and a database keys are close the same thing. The idea is to have a unique identifier created for the records that can be used later for faster joins.
  9. Add new fields to fldzonewarea for Population (long integer, 20 precision), Population Density (double, 20 precision, 4 scale), percent owner-occupied (double, 10, 4), percent renter-occupied (double, 10, 4). Field names are your choice, but keep it to 8 characters or fewer.  Because you are using a joined table, the newly added fields are saved to the destination table (the one to which you joined, fldznwarea). So when you calculate the fields below, be aware that the naming convention of the field will be tablename.fieldname. For example, I named my population field POP2000, so my newly added field is fldznwarea.POP2000.
  10. Be prepared to convert the square units of the area calculation (F_AREA) to square miles. I like to use http://www.onlineconversion.com/
  11. Calculate the new fields using the joined table information. For example, if I do my calculation using the options available from the open attribute table, my first expression looked like this….fldznwarea.POP2000 = [Sum_Output.Sum_POP2000], and then my population density would be fldznwarea.POPDEN = [fldznwarea.POP2000] / ([fldznwarea.F_AREA]/the conversion number you figured out). Note my syntax for doing mathematical operations in the calculation window. I put the parenthesis in because you need to break up your operation…the computer automatically assumes a left to right calculation process….not what you were taught in math class when you were taught to do certain operations first, second, third, etc…. You may do percentages with or without multiplying by 100, just be careful of syntax and remember what you did when you enter the numbers in the answer sheet table.
  12. After you get all the calculations done, remove all Joins.
  13. Use your table to fill out the information on the answer sheet.

 

Overlay with Zip Codes

  1. Using the same process above, intersect syrzipgcs83 with fldznewarea (this time I’m not going to worry about the inaccuracy of using different coordinate systems because the results will be close enough for our purposes).
  2. Fill out the answer sheet with the information (the list of zip codes…except the 132HH one).

 

Checking Dams, Watersheds and Wetlands

  1. Add onowtlndsutm83, onowtrshdsutm83, and Syracuse (the city boundary layer).
  2. How many dams do we have to worry about upstream from the flood zones? What two separate watersheds contain the flood zones? Are there any wetlands below the dams and along the flood zones within the city boundary that can help us buffer flood surges?
  3. Use the layers (and their table information) to fill out the answer sheet.

 

Creating the Interstate Layer

  1. Use the select tool from ArcToolbox as you did with the flood zones to create syrinterstates from syrroads. The interstate codes are A11 and A15 found in the CFCC field.  For the Boolean logic operator use OR.

 

Output

 

To do the map, you will have to manipulate the layer position (from top to bottom), whether the layer is on or off, and the symbolization. This time, I’m not going to give you specific direction on how to make the map. Use Lab 3, Michelle’s power point on map composition, the support documents on the webpage, and help to guide you.  The deadline is intentionally extended to give you time to experiment with these features.

 

Fill out the table and answers to questions on the answer sheet. Fill out the spatial model.

 

Produce one map using the NAD83 datum and UTM Zone 18N projected coordinate system with interstates, railroads (syrrrgcs83), the armory, the dam, the surface and network hydrography, the wetlands, and the census blocks intersecting the flood zones symbolizing population.

 

First, to make sure the map is in the projected coordinate system, right click on an open (no data) area in the data view in ArcMap and select properties. Then click on the coordinate system tab and use the folders to select the correct coordinate system.

 

Second, to display the whole blocks that intersect with the flood zone, join the syrblksutm83 to the layer you named after intersecting fldznwarea and syrblksutm83 using the advanced option to join only the matching records.

 

Third, use symbolization appropriate for a black and white printer (Symbolization is accessed by right clicking on the layer, selecting properties, and using the symbolization tab). For population symbolization use the POP2000 field.

 

Make sure your map has a title, legend, scale bar, north arrow, your name and date, and attribution given to NYS DEC, USGS, US Army Corps, and U.S. Census.

 

For up to 10 bonus points (will be added to your overall lab scores) do two black and white maps symbolizing the percent of owner-occupant housing units and percent renter-occupied housing units by census block. Up to five points will be given if you do only one map. These maps must have the required map elements.