Title: Exercise 6 ArcView 8 Population Demographics Adjacent to National Estuarine Research Reserves
1Exercise 6 - ArcView 8Population Demographics
Adjacent to National Estuarine Research Reserves
Part 2
Courtesy of
Written by OSU Marine Resources Mgmt. student
Danielle Pattison
2Introduction Skills Learned
- Before beginning this exercise, please copy the
data directory \\sci-geo\geo265\data\ex6_coast to
your student working directory. - For this exercise, please turn in your lab
report, including answers to the questions posed
in the exercise, as well as the requested map
layout. You will also hand in your lab notebook.
Again, please refer to the syllabus for complete
guidelines on writing these two documents. - After completing this exercise, you will have the
skills to - Use and understand Census data
- Join and relate tables
- Add and calculate table fields
- Use various legend classifications and symbols
- Create maps with multiple data frames
- Use Coastal Change Analysis Program (C-CAP) data
3Part 1 Formatting Data for Analysis
- Background
- As a coastal resource manager, you are concerned
with the health and vitality of the nations
coastal areas. With coastal populations on the
rise, you are particularly interested in marine
protected areas and how well they are actually
being protected from the human activities outside
their borders. In this exercise you will look at
National Estuarine Research Reserves (NERRs) in
New England and determine the areas of influence
around them. One of the challenges will be
dealing with the differences between natural and
physical boundaries. Physical processes may occur
within natural boundaries, but data is often
available and management decisions made in
accordance with political boundaries. Therefore,
you will have both watershed and county
boundaries to work with. Once you have determined
your areas of influence, you will also need to
find and incorporate demographic data for those
areas in preparation for Exercise B.
Goal After hearing the lecture and working
through the exercises, the student will be able
to select features based on location and create
new layers containing these data. The student
will also be able to find and understand census
data, as well as being able to join this and
other tabular data to existing shapefiles.
- Objectives
- Reselect watersheds that intersect NERRs
boundaries - Reselect counties that intersect and influence
these watersheds - Join the table containing population statistics
and demographic data for 2000 with the county
shapefile table
4Part 1 Formatting Data for Analysis
Select By Location Use this function to select
features based on their location relative to
another feature Join Data Use this
function to append additional data to a layers
attribute table
Tools to Use
Data New_England2.mxd ArcMap document states
Polygon layer of US states NERRs Polygon
layer of US NERRs ne_states Polyline
shapefile of New England states ne_watersheds
Polygon shapefile of New England
watersheds ne_counties Polygon shapefile of
New England counties nerr_counties.lyr
Polygon layer file of counties that intersect
with NERRs ne_dem_2000.dbf DBF table of New
England census demographic data
- Summary of Process Steps
- Select New England NERRs by Location Create a
new shapefile of the NERRs that are located in
the New England states - Select Watersheds by Location Create a new
shapefile of watersheds that intersect the New
England NERRs - Select Counties by Location - Create a new
shapefile of counties that have significant area
within the chosen watersheds - Find Census TIGER Data - Use the Internet to find
sites where 2000 Census TIGER data is available
to download - Join Table to Shapefile Join the 2000
demographic data to your county shapefile
5Part 1 Formatting Data for Analysis
- Transparency
- You can make raster, TIN, and feature layers
transparent in scenes and maps. For example, you
can use transparent layers to - Visualize data that is scattered above and below
a reference plane - Compare two surfaces
- Show terrain and subsurface features at the same
time - You can also use the Adjust Transparency tool on
the Effects toolbar in ArcMap to set the
transparency for a layer.
Did You Know?
- 1. Select New England NERRs by Location
- To begin, start ArcMap . When prompted,
select to start the program with an existing map,
navigate to the ex6_coast data directory in your
student working directory and select the
New_England.mxd ArcMap document file. - Turn on the NERRs layer.
- Notice that the NERRs layer, showing the nations
estuarine research reserves, is hard to see
unless you turn off the States layer. Instead of
having to do that, you can make the state layer
partially transparent. - Double click on states.shp to open the Layers
Properties dialog box. Click on the Display tab,
and set the Transparent value to 75. Click OK. - Which coast of the US are most of the NERR sites
located on? - ______________________________________________
_____________ -
- You will select and work with those sites within
the New England states. - Turn on ne_states, right click on it, and select
Zoom To Layer.
6Part 1 Formatting Data for Analysis
- Select New England NERRs by Location (contd)
- On the menu bar,
- click Selection gt Select by Location.
- Choose to select features from
- The NERRs layer
- That intersect
- The features in the ne_states layer
- Click Apply and Close
7Part 1 Formatting Data for Analysis
For more information on the National Estuarine
Research Reserves System visit http//www.ocrm.nos
.noaa.gov/nerr/
Web Sites
- 1. Select New England NERRs by Location (contd.)
- As you can see, there are four National Estuarine
Research Reserve sites within New England. One
each in Maine, New Hampshire, Massachusetts, and
Rhode Island. They are the Wells NERR, Great Bay
NERR, Waquoit NERR, and Naraganset NERR
respectively. - To create a separate shapefile of just these
selected sites, right-click on NERRs and choose
Data gt Export Data. Export the selected features
using the same coordinate system as the layers
source data, and save it in your student
directory under /ex6 as new_nerrs.shp. - Click Yes to add the data to your map.
- Right-click on NERRs, and choose Selection gt
Clear Selected Features. Turn off NERRs. - Again, your new NERRs layer may be hard to see
until you change the color. Double click on the
symbol box of new_nerrs and change the fill color
to a bright red. Change the outline color to red
as well. Click OK.
8Part 1 Formatting Data for Analysis
Watersheds That area of land, a bounded
hydrologic system, within which all living things
are inextricably linked by their common water
course and where, as humans settled, simple logic
demanded that they become part of a community."
John Wesley Powell, geographer Remember - no
matter where you are, you're in a watershed!
Did You Know?
- 2. Select Watersheds by Location
- Now that you have the New England NERRs, you want
to know which watersheds they are part of. - Turn on the ne_watersheds shapefile.
- Choose Selection gt Select by Location. Set the
parameters so that you are selecting features
from ne_watersheds that intersect with new_nerrs.
Click Apply. Close the dialog box when it is
finished. - Zoom in on the selected watersheds. In the Table
of Contents, right-click on ne_watersheds and
choose Selection gt Zoom to Selected Features. - Right-click on ne_watersheds and export the data
as a new shapefile to your student directory.
Name it nerr_watersheds. As before, export just
the selected features and use the source data
layers coordinate system. - Add the new data layer to the map.
- Right click on ne_watersheds, Selection gt Clear
Selected Features. Turn off ne_watersheds.
9Part 1 Formatting Data for Analysis
Spatial Bookmarks A spatial bookmark
identifies a particular geographic location that
you want to save and refer to later. Bookmarks
are easy to create. Once you have your data view
set to a particular area, simply go to View gt
Bookmarks gt Create As you pan and zoom around
your map, you can easily return to the study area
by accessing the bookmark.
Did You Know?
- 3. Select Counties by Location
- You will now select the counties that contain
these watersheds, and therefore influence the
NERR sites. - Turn on ne_counties.
- It is difficult to see the county borders
underneath the watershed polygons. Making
nerr_watersheds partially transparent will allow
you to view both layers and all their boundaries.
Also, if your new shapefiles are assigned colors
which are not easy to distinguish from the
others, always feel free to change the symbol
color. - Open the Layer Properties for nerr_watersheds.
Click the Display tab and make the layer 40
transparent. - From the menu bar, click on View gt Bookmarks.
Select RI_watershed. - Right-click on ne_counties, and choose Label
Features. - You are looking at the area surrounding the
Narragansett NERR in Rhode Island. As you can
see, the watershed for this area overlaps several
counties. Some more than others. For example,
Worcester and Plymouth counties each have
substantial areas within the watershed zone.
Middlesex County, on the other hand, overlaps the
watershed by just a small piece. You want to
select only those counties with at least a
moderate impact on the watershed area.
10Part 1 Formatting Data for Analysis
- 3. Select Counties by Location (contd)
- Navigate to Select by Location.
- In the Select by Location dialog box, choose to
select features from the ne_counties layer, that
have their center in features from the
nerr_watersheds layer. Click Apply. - Move the dialog box to the side, and see that
many of the influencing counties surrounding the
NERR have been selected, but not all of them. You
will now add to your selection those counties
which do not have their center within the
watershed region, but are still considered
significantly within the watershed. - For your next selection in the Select by Location
dialog box, choose to add to the currently
selected features in, and keep ne_counties
checked. Choose those features that are within a
distance of features in nerr_watersheds. - You will notice that the option to enter a
distance buffer becomes available. Enter 2, and
change the units to miles. This will select those
counties which overlap the watershed by at least
2 miles. Click Apply. - Close the dialog box when the selection process
is complete.
11Part 1 Formatting Data for Analysis
- 3. Select Counties by Location (contd)
- Right-click on ne _counties and turn off the
labels. Then choose Selection gt Zoom to Selected
Features. - Export the selected features to create a new
shapefile. Name this layer watershed_counties.shp
and save it to your student directory. Choose Yes
to add this data to your map. - Clear the selected features from ne_counties, and
turn the layer off. - Rearrange your Table of Contents so that the top
three layers are new_nerrs, nerr_watersheds, and
watershed_counties in that order from top to
bottom. To move a layer, simply highlight it and
drag it up or down in the Table of Contents. - You now have those counties which influence the
New England NERR sites selected and in a separate
shapefile to work with for the rest of this
exercise. - Why was it important to select counties that
overlapped with the watershed regions, instead of
just those that intersected with the boundaries
of the NERRs? - (answer in your lab report)
-
12Part 1 Formatting Data for Analysis
The TIGER/Line files are a digital database of
geographic features, such as roads, railroads,
rivers, lakes, political boundaries, census
statistical boundaries, etc. covering the entire
United States. The TIGER/Line files are
downloaded in compressed shapefile format for a
selected county or data layer. TIGER stands for
Topologically Integrated Geographic Encoding and
Referencing
Did You Know?
- 3. Select Counties by Location (contd)
- To see a comparison, add
nerr_counties.shp to your map. The area around
Narragansett NERR is a good example of how many
counties would have been missed without
considering the watershed coverage. - Remove nerr_counties from the Table of Contents.
- 4. Find Census TIGER Data
- Census data can be very useful in evaluating and
understanding the geographic patterns of human
activity. These data can also help us visualize
the proximity of the activities to environmental
areas. Understanding the types and extent of
certain activities can aid coastal managers in
protecting coastal areas and resources. - Open the Attribute Table for watershed_counties,
and examine the various data fields. Notice that
this table contains 1990 population data for each
of the selected counties. -
- More up to date population figures are available,
as well as a variety of other demographic data.
You will find and use Census TIGER data for this
additional information.
13Part 1 Formatting Data for Analysis
The Geography Network is an online resource for
finding and sharing geographic content, including
maps and data, from many of the world's leading
providers. The Geography Network can also be
accessed directly through ArcMap! File gt Add Data
from Internet gt Geography Network For this
exercise we are using Census County Demographics
(SF1).
Did You Know?
- 4. Find Census TIGER Data (cont.)
-
- Open Internet Explorer and go to www.google.com.
Search for 2000 census tiger data - The first entry of your search results should be
Geography Network. Click on this entry to go to
the Geography Network site. - This is a site, operated by ESRI, where you can
easily download free Census Tiger data. Click on
the link to Download Data. - The next page allows you to choose Census data by
state. Select any state of interest to you,
either by clicking on the map or selecting the
state name from the drop down menu. - The following page is where you select the data
you wish to download by county or data layer.
Take a moment to explore this page, particularly
the various options under the Select by Layer
menu to become more familiar with the types of
data available. In your lab report, briefly
describe some of the files that you have
downloaded and opened due to your own interest.
Include the readme file from one of the layers in
your lab report. - In the interest of time, the necessary data for
all the New England counties has been downloaded
and put into a single table for you. It is
important however, for you to know where this
data came from, in the case that you need to use
Census data in the future. - Close the Geography Network window.
FYI
14Part 1 Formatting Data for Analysis
Did You Know?
If you have information stored in a table,
such as a dBASE, INFO, or geodatabase table, you
can associate it with your geographic features
and display the data on your map by one of two
methods Joining tables - appends the attributes
from one table onto the other based on a field
common to both tables. Relating tables - defines
a relationship between two tablesalso based on a
common fieldbut doesn't append the attributes of
one to the other. Instead, you can access the
related data when necessary.
- 5. Join Table to Shapefile
- In the next exercise you will calculate the
population change between 1990 and 2000. In order
to do that, you will join a table of 2000
demographic statistics, including population, to
your watershed_counties layer. - If necessary, open the attribute table for the
watershed_counties layer. - Use to add the table called
ne_dem_2000.dbf. from the data folder. This table
is the previously mentioned aggregate file of
Census Tiger data, and contains the demographic
data for all the New England counties. Right
click on the title and open the table. - Arrange the two tables so you can view the field
headings of both at the same time. -
- In order to join two tables they must share a
common field, known as a common key. Look at the
column titled FIPS in the watershed_counties
table. Compare that to the STFID column in the
ne_dem_2000 table. They have different headings,
but both contain unique identifying numbers
referring to the same thing. (The first two
numbers are the state code, and the last three
numbers are the county code). You will use these
fields as the common key for the tables. - Remember, watershed_counties is a subset of
counties you created from ne_counties so it does
not contain records for every county in New
England, as ne-dem_2000 does. You are only
interested in the information from ne_dem_2000
that corresponds to the counties in your
watershed layer. - Close the Attribute Tables.
15 Part 1 Formatting Data for Analysis
- 5. Join Table to Shapefile (contd.)
- Since you will be joining data to
watershed_counties, begin by opening its Layer
Properties. In the Layer Properties box, click on
the Joins Relates tab. Under Joins, click the
Add button. - Make sure the first pull-down menu is set to Join
attributes from a table. - Choose FIPS as the field to base the join on.
- Choose ne_dem_2000 as the table being joined.
- Choose STFID as the other field to base the join
on. - Click OK.
-
16Part 1 Formatting Data for Analysis
- 5. Join Table to Shapefile (contd)
- In the Layer Properties box, click on the Fields
tab. Examine the new fields that have been added.
You will have to widen the Name field to view the
field titles in this table. Notice that the title
now includes the name of the table it originated
from. This is particularly helpful when you have
commonly named fields. - Close Layer Properties and any open tables.
- Save your map document.
- In Part 1 you selected NERRs in New England,
selected watersheds that intersected with the New
England NERRS, and selected counties that were
significantly within those watersheds. You did
this to find the counties whose populations and
activities have an influence on the NERR sites.
Once you had these counties, you were able to
join Census TIGER data to your county shapefile. - In Part 2 you will use this and other
demographic data to look at and map various
population and environmental parameters. -
-
17Discussion Applying These Skills Elsewhere
- Can you think of other scenarios where political
vs. natural boundaries could be an issue? (answer
in your lab report)
18Part 2 Analysis and Display of Demographic Data
- Background
- Now that you have determined the areas
influencing the New England NERR sites, your
interests will focus on the population changes
and demographics of these areas. After looking
for areas of especially high population change,
you will concentrate on Barnstable County,
Massachusetts, the location of the Waquoit NERR.
It will be up to you to determine which of the
county demographic data is most important to
consider for coastal management purposes, and the
best way to display the information you have.
- Goal
- To use census and other tabular data to calculate
and represent population changes. The student
will also have the skills to display demographic
information in an appropriate and meaningful
way. - Objectives
- Perform table calculations
- Use and understand different legend
classifications - Create a map layout using multiple data frames
19Part 2 Analysis and Display of Demographic Data
Field Calculator Use this tool to perform
mathematical calculations to set a field value
for a single record or all records. Join
Data Use this function to append additional data
to a layers attribute table Change
Layout Lets you change the layout of your map by
choosing a different template
Tools to Use
- Summary of Process Steps
- Add and Calculate a New Field show the
population change between 1990 and 2000 - Display Population Data look at several
population parameters including total population,
population density, and population change - Join Tables join demographic data to a county
shapefile - Use Different Classification Methods use and
understand the various classification schemes
available in ArcMap - Layer Symbology learn more about the tools
available to effectively display your data - Choose Four Demographic Parameters to Map select
and customize maps for four parameters of
interest to coastal managers - Create a Map From a Template a quick look at
some of the templates available in ArcMap - Create a Map Layout with Multiple Data Frames
use the Layout View to customize your map - Tips For Customizing Your Map Layout tips for
adding map features, customizing legends and data
frames
Data New_England.mxd ArcMap
document nerr_watersheds.shp Polygon shapefile
of watersheds adjacent to NERRs watershed_counties
.shp Polygon shapefile of watershed
influencing counties trt25001.shp Polygon
shapefile of Barnstable census tracts t9025001.dbf
DBF table of Barnstable demographics York.mxd
ArcMap document
20Part 2 Analysis and Display of Demographic Data
- 1. Add and Calculate a New Field
- If necessary, start ArcMap and open the
NewEngland.mxd map document you saved from the
previous exercise. Open the Attribute Table for
watershed_counties.shp. - You will now create a new field to show the
population change from 1990 to 2000. - In the Attribute Table click on Options gt Add
Field. Name the new field pop_chng and change the
Type to Long Integer. Click OK. - The new field will be inserted as the last column
of the original data set, in this case the last
column with watershed_counties in the title. - Right-click on the new field header and choose
Calculate Values. - A message will pop up warning you that you have
not started an editing session. Click No to exit
the message, and begin an editing session. To do
this, Click Editor on the Editor toolbar and
choose Start Editing. In the Start Editing dialog
box, highlight your source folder (ex6_coast in
your directory) and make sure watershed_counties
is listed as being available for editing. Click
OK. - Return to Calculate Values to bring up the Field
Calculator.
21Part 2 Analysis and Display of Demographic Data
Mouse Over Tip Sometimes layer titles are
longer than the spaces provided for them (as in
the Field Calculator) and are hard to read.
Rather than having to scroll over to read the
full title, hold your cursor over the layer name
for a second and the name will appear in its
entirety!
FYI
- 1. Add and Calculate New Field (contd.)
- In the Field Calculator set the expression to
read - ne_dem_2000.POP2000 watershed_counties.POP19
90 - Click OK.
- After the calculations have completed, take a
moment to look at the numbers. It may be easier
to put them in order. To do so, right-click on
the field heading and choose Sort Descending. - Which county has experienced the greatest
population change? Does any one state appear to
be changing more than the others? Have any county
populations decreased? Which one(s)? (answer in
your lab report) -
- Close the Attribute Table when you are finished.
22Part 2 Analysis and Display of Demographic Data
- 2. Display Population Data
- Now that you have joined the demographic data to
the watershed_counties layer, you can use the new
attributes to symbolize the layer. - Zoom to the extent of watershed_counties and turn
off the nerr_watersheds layer. - Double click on watershed_counties and select the
Symbology tab if necessary. - Choose to Show Quantities, and Graduated colors.
- For Value, select ne_dem_2000.POP2000. Drag the
Properties box to the side so you can view your
map. Click Apply. - This is showing the population, or number of
people, in the selected New England counties.
While this is useful information, it may not be
the best way to show how populated each of the
counties are. Now you will look at population
density, or the population per square mile. This
can be done two ways. You could create a new
field in the attribute table and calculate the
population density (pop2000/area), as you did to
find the population change. You can also
normalize, or divide one attribute by another,
and get the same result. Normalization can be
done in the Symbology section of the Layer
Properties box.
23Part 2 Analysis and Display of Demographic Data
- 2. Display Population Data (contd)
-
- With Value still set to ne_dem_2000.POP2000,
select watershed_counties.AREA for Normalization.
Click Apply. Notice how the classification of the
counties changes on the map. - Set Normalization back to NONE. Choose the field
you created, watershed_counties.pop_chng, as the
Value. Click Apply. This shows how much the
population changed between 1990 and 2000. - You have seen how displaying population data
differently affects the map. When might you be
interested in each of these three parameters?
Total population population density population
change? (answer in your lab report) - For the remainder of this exercise you will focus
on a county that is experiencing a high degree of
population change. As you can see on your map,
the area around Waquoit NERR on Cape Cod,
Massachusetts has undergone some of the highest
levels of population change. We will look more
closely at Barnstable County. - Close Layer Properties.
-
24Part 2 Analysis and Display of Demographic Data
- ArcMap supports project on the fly, meaning that
you can make a map in one projection(referred to
as a coordinate system) and have your data stored
in any number of projections. - To enable a feature layer to be projected on the
fly, ArcMap needs to know the source coordinate
system (for the layer) and the target coordinate
system (for the Map display).
Did You Know?
- 3. Join Tables
- You will now add two new items specific to
Barnstable county. One is a shapefile of
Barnstable county divided up by census tracts.
The other is a table with the associated
demographic data by census tracts. These data are
Census TIGER files and were downloaded from the
Geography Network Web site. -
- Add trt25001.shp and t9025001.dbf from the data
folder in your student directory. A warning box
will pop up telling you that these items are in a
different projection than your current map
projection. Click OK. For the best possible
alignment and accuracy you would want to actually
change the coordinate system of the new layers,
but for our simple viewing purposes ArcMaps on
the fly projection change is sufficient. - In the Table of Contents, change the layer name
of trt25001.shp to Barnstable census tracts. Turn
off all layers except Barnstable census tracts.
Zoom to that layer. - Open the tables for the Barnstable layer and
t9025001.dbf. Scroll all the way to the right in
t9025001. The common field for these tables is
titled KEY. This is the field you will use to
join the two tables. Close both tables. - Join the table t9025001 to the Barnstable census
tracts layer. (Remember, this is done through the
Layer Properties box of the Barnstable layer).
Make sure that you understand the process. -
25Part 2 Analysis and Display of Demographic Data
- 4. Use Different Classification Methods
- Open the Layer Properties for the Barnstable
layer and click on the Fields tab. Scroll through
the list of fields to see what new information is
available to you. There are significantly more
data fields at the census tract level than there
were at the county level. - Click on the Symbology tab. Under Show, select
Quantities Graduated colors. For Value, select
t9025001.PERSONS. Move the Properties box to one
side so you can view your map. Click Apply. - Notice in the Classification section of the
Properties box, where it says Natural Breaks
(Jenks). This is the default method of
classification in ArcMap. This method uses
natural groupings or patterns in the data to
define classes and shows clusters or
concentrations of values. -
-
26Part 2 Analysis and Display of Demographic Data
- The most common classification methods are
- Natural Breaks identifies breakpoints between
values - Quantile each class contains the same number of
features - Equal Interval divides values into equal ranges
- Standard Deviation shows distributions above
and below the mean
Did You Know?
- 4. Use Different Classification Methods (contd)
- Also notice that a border of water surrounding
Cape Cod is included in this layer and is being
classified. Look at the classification ranges.
The first one goes from 0 1100. Since we arent
interested in the water area, we can assume it
has zero persons and exclude it from our data
display. -
- In the Properties box, click Classify. Click
Exclusion. - Under the Query tab, set the expression to read
"t9025001.PERSONS" 0 - Under the Legend tab, make sure the box for show
symbol for excluded data is unchecked. Click OK.
Click OK in the Classification box, and then
Apply in the Properties box. - Not only does the map look better without the
surrounding water area, those 0 values will no
longer be incorporated into classification
schemes, which could potentially skew the
results. - Return to the Classification box by clicking on
Classify. Examine the graphical display. The blue
lines on the graph show where the data are broken
into different classes. Put your cursor over one
of the lines. The cursor turns into a
side-to-side arrow, allowing you to click on and
move the break line to a new value. Notice that
as soon as you do this, the method type
automatically changes to Manual. The Break Values
listed to the right also reflect the changes
being made.
27Part 2 Analysis and Display of Demographic Data
- 4. Use Different Classification Methods (contd)
-
- Change the Classification Method type to Equal
Interval. This classification scheme divides the
range of attribute values into equal-sized
subranges. For example, values that ranged from
0-50 and had 5 classes, would be divided as
0-10,11-20, 21-30, etc. - Click OK and Apply to see the changes on the map.
What do you think of the changes? This map
doesnt show as much variety between counties.
Look again at the graphic in the Classification
box. Notice that most of the data fall within 2
classes, so this classification type would
probably not be the best choice for this data
set. - What types of data may be better suited for equal
interval classification? (answer in lab report) -
- This time, change the Classification Method to
Quantile. In a quantile classification, each
class contains an equal number of features. Click
OK and Apply to see the changes on the map. - For any of these classification methods, you can
also change the number of classes. Experiment
with this for a moment. - As you have seen, your map will look very
different depending on the classification method
and number of classes you choose to use. An
important aspect of displaying any data is
finding the combination best suited for your data
and what you want it to show.
28Part 2 Analysis and Display of Demographic Data
- 5. Layer Symbology
- In addition to changing the way your data is
classified, you have many other options available
as to how to display your data. - Under Show Quantities, change from Graduated
color to Dot density. Highlight t9025001.PERSONS
in the Field Selection box, and click on the
arrow to move it into the box on the right.
Change the Dot Value to 500, and click Apply.
Each dot represents 500 people. - This time, change the Symbology to Proportional
symbols. Select t9025001.PERSONS for the Field
Value. This time you get a warning about this
field having some zero values and asking you to
exclude them. Using the Exclude button, exclude
the data where persons equal zero, just as you
did previously. Click Apply. In this case, the
symbol size represents total population values. - To look at population density, normalize
t9025001.PERSONS to the size of the counties. (In
this case, t9025001LAND_KM). Areas of high
population density are now much easier to
distinguish. -
29Part 2 Analysis and Display of Demographic Data
- Styles
- An organized collection of symbols and map
elements - ArcMap starts with two default symbol styles
ESRI and a Window-generated symbol set. - Many other industry specific (civic, weather,
evnironmental, real estate, etc) styles can be
accessed at - Tools gt Styles gt Style Manager.
- There are over 12,000 symbols available in ArcMap!
Did You Know?
- 5. Layer Symbology (contd)
-
- Under Show, click on Charts and select Pie. This
type of symbology makes it easy to compare
related fields. As an example, well look at how
people in this area get to work. - About halfway down the Field Selection box,
highlight and move to the right the fields
DRVALONE, CARPOOL, and PUBTRANS. Click the Size
button, and change to size to 22 pts. Click OK
and Apply. - Lets say you are particularly interested in
seeing the percentage of commuters who use public
transportation. The color scheme is randomly
assigned for the pie chart, but you can change
it. Double click on the symbol next to PUBTRANS
in the Layer Properties box, and change it to
bright yellow. Click Apply. - Finally, change the classification back to
showing population density in Graduated colors
using Natural breaks. - Close Layer Properties.
-
-
30Part 2 Analysis and Display of Demographic Data
- 6. Choose Four Demographic Parameters to Map
- Read this section so that you understand your
objective, and then move onto sections 7 and 8
for further instructions and tips on creating
your map layout. - Choose four parameters that you think would be of
interest to a coastal manager for the area. They
can be ones you have already worked with, or new
ones. Look through the attribute table and see
what you can come up with. Try to incorporate
some of the different classification methods and
symbology styles you have just learned about. - Choose between either Wells NERR in York, Maine
or Waquoit NERR in Barnstable, Mass. If you
choose to work with York, Maine, you will find a
York.mxd map document in the data folder with the
necessary files. - Feeling stuck? Start with something simple like
population density, either as a graduated color
or proportional symbol. Or show housing units
using dot density. How about a pie or bar chart
of residences that use public vs. private sewage
systems? You could show the ratio of housing
units that are renter occupied versus owner
occupied, rental rates by graduated color, which
counties have a majority of seasonal residents,
or look for areas with older homes those built
prior to 1970. -
31Part 2 Analysis and Display of Demographic Data
- Template saving tip
- If you save a template in the ArcMap Templates
folder (\ArcGIS\arcexe82\bin\ - Tempates), it will show up in the list of
templates on the General panel of the New map
document dialog box.
FYI
- 7. Create a Map From a Template
- Before you begin your own layout, you will see
how templates can be used to make quick and easy
maps. - If necessary zoom to the extent of the Barnstable
layer. - Change to the Layout View by clicking on the
tab near the bottom of the map view. - Go to File gt Save as. Navigate to your student
working directory, name your file Blank, and
change the file type to .mxt. You have just saved
a blank template that you will be using in the
next exercise. - Click the Change Layout button on the
Layout Toolbar. - In the Select Template box, click the General tab
and highlight LetterLandscape.mxt. Click Finish.
Notice that the template includes a standard
title area, north area, scale bar and legend. You
can click on any one of these and drag it to a
more appropriate place on your map layout. - Click the Change Layout button again. This time
choose LandscapeClassic.mxt. -
- These are just a few of the many templates
available to you. Explore them more thoroughly on
your own when you have time.
32Part 2 Analysis and Display of Demographic Data
- 8. Create a Map Layout With Multiple Data Frames
- In this section of the exercise you will be
creating one map layout comprised of four
separate maps. Each of the four maps will come
from a different data frame in ArcMap. So far you
have been working with all your data in one data
frame. You will need to create three more data
frames. The same data layers can be used in all
the data frames, but each can be customized to
show something unique. - Click the Change Layout button and under the My
Templates tab, select the blank.mxt template you
created in the previous section. - Under File gt Page Setup, change the Page
Orientation to Landscape. - In the Layout View, click on the data layout.
Once it is highlighted, grab a corner and reduce
it to about ΒΌ the size of the page. Position this
data frame in one quadrant of the page. - Your default (and only) view at this point is
named Layers. Rename it to Data Frame 1. You can
do this by clicking on the title in the Table of
Contents, or by going through its Properties box.
Also in the Data Frame Properties box, click on
the General Tab and change the display units to
Miles. The map units should be decimal
degrees. -
33Part 2 Analysis and Display of Demographic Data
- 8. Create a Map Layout With Multiple Data Frames
(contd) - You will now create three more data frames. Click
Insert gt Data Frames. In the Layout View resize
it to be the same as Data Frame 1. Reposition it
in another quadrant of the page. In the Table of
Contents rename the New Data Frame to Data Frame
2. - Repeat this process until you have four Data
Frames. -
- When you are sizing and positioning your data
frames, you may want to leave space at the top of
the page for a title and at the bottom for all
the other important cartographic elements that
you need to include on your map (Remember the SIX
cartographic elements!). - In order to work with an individual
- data frame, it must be active.
- You can make a data frame active
- by clicking on it in the Layout View
- or right-click it and select Activate
- in the Table of Contents.
34Part 2 Analysis and Display of Demographic Data
- 8. Create a Map Layout With Multiple Data Frames
(contd) - If you havent done so already, rename your new
data frames Data Frame 2, 3, and 4. - In Data Frame 1 in the Table of Contents,
right-click on Barnstable census tracts and
select Copy. Paste it into each of the other
three Data Frames. (Right-click on each of the
Data Frames in the Table of Contents and click
Paste Layer) - Now you are ready to begin customizing each data
frame to display a different parameter from the
data available to you. You can switch back and
forth between the Data View and the Layout View.
The Data View will show only the active data
frame and it may be easier to work with the
individual data frames in this mode. - Feel free to copy and paste any other layers into
your new data frames as needed. For example,
having new_nerrs would be useful to show where
the Waquoit (or Wells) NERR is in relation to the
demographics within the county. - See the next page for suggestions on customizing
your map. As you customize a data frame, have
fun, and be creative! - When you have finished, save your map document
and prepare a copy (screen shot) of your map for
your lab report. Close ArcMap. -
35Part 2 Analysis and Display of Demographic Data
- 9. Tips For Customizing Your Map Layout
-
- Since you are not using a template, you will
need to add your own legend, north arrow, and
scale bar. This can be done using the Insert
portion of the menu bar. - The Legend Wizard that comes up when you click
Insert gt Legend, offers a variety of options for
customizing your legend. It is relatively self
explanatory and allows you to - - choose which layers to include in your legend
- - change background colors and border styles
- - change symbol patch styles
- You can also change layer titles. When you
customize the symbology of each layer, an
additional title gets added to the layer
describing the classification. For example, look
at the Barnstable census tract layer in any of
the Data Frames. If you havent already changed
it, the sub-title should read t9025001.PERSONS/t90
25001.LAND_KM. Not a very clear title to have on
your map legend! Highlight the sub-title and
click it once to change the name to something
more appropriate, like Population Density.
Changing it in the Table of Contents will
automatically update it in your layout, even if
youve already added the legend for that Data
Frame. - To customize the look of the data frame itself,
you can double click on the Data Frame title in
the Table of Contents or right-click gt Properties
on the data frame in the Layout View. This brings
up the Data Frame Properties box. Go to the Frame
tab to change the background colors and border
styles of each data frame. -
-
36Discussion Overview of Management Applications
- Which parameters did you choose to include in
your map? - 2. What other data would you like to have
analyzed, given more time? - (answer these questions in your lab report)
37Part 3 Using C-CAP Data to Determine Impervious
Surfaces
- Background
- Land cover information can give you, a coastal
resource manager, insight into how the land in
your area is being utilized. This in turn can
help determine the impact of different coverage
types on local habitats or water quality. In this
exercise you will find the amount of impervious
surface in two NERR watersheds and compare the
results. Impervious surfaces are of interest
because they are a main contributor to surface
water runoff and its effects, including water
quality degradation, erosion, flooding and
sedimentation. You will use land classified as
Developed to determine imperviousness since
development results in more paved surfaces and
less area for water to drain into soils. - It should be noted that for Part 3 we are
considering all developed land to be impervious.
While this will only give us a very rough
estimate, it is adequate for our comparison
purposes. You will be given the opportunity to do
more precise calculations in the Challenge
Exercise.
- Goal
- After completing the exercise, the student will
better understand C-CAP data and how they can be
used in coastal management. - Objectives
- Become familiar with C-CAP data
classifications - Use C-CAP data to determine the percentage of
impervious surface within watersheds
38Part 3 Using C-CAP Data to Determine Impervious
Surfaces
- Select By Attribute Use this function to select
features based on their attributes - Statistics
- Use this function to get statistics describing
the values in a tables numeric columns, such as
the sum, minimum, mean, maximum, and standard
deviation of those values. -
Tools to Use
Data CCAP.mxd ArcMap document ne_nerrs
Polygon shapefile of NERRs in New
England nerr_watersheds Polygon layer of
watersheds adjacent to NERRs nh_nh19930612.img
C-CAP land cover image of New
Hampshire ma_ma19970623.img C-CAP land cover
image of Massachusetts NHnerr_landcov C-CAP
land cover layer of Great Bay NERR
area RInerr_landcov C-CAP land cover layer of
Narragansett Bay NERR area
- Summary of Process Steps
- Examine C-CAP data classifications familiarize
yourself with the classification schemes used in
C-CAP data - Determine the percentage of impervious surface in
the Great Bay NERR watershed use the Select by
Attribute function and table Statistics to
calculate this percentage - Determine the percentage of impervious surface in
the Narragensett Bay NERR watershed repeat the
process for the Rhode Island NERR watershed
39Part 3 Using C-CAP Data to Determine Impervious
Surfaces
For more information on the CCAP data, visit
www.csc.noaa.gov/crs/lca/ccap.html To
download CCAP data, visit www.csc.noaa.gov/crs/l
ca/locate.html Or www.csc.noaa.gov/crs/lca/locatef
tp.html
Web Sites
- Examine C-CAP Data Classifications
- Start ArcMap and open the CCAP.mxd map document..
You are looking at two full C-CAP scenes covering
much of the New England coastal area. - Turn on ne_nerrs and zoom to the Wells NERR (WEL)
in Maine.
40Part 3 Using C-CAP Data to Determine Impervious
Surfaces
- Examine C-CAP Data Classifications (contd)
- Turn off ne_nerrs and examine the land cover in
the Wells NERR. Consult the C-CAP legend in the
Table of Contents. - What type of land cover makes up most of the
Wells NERR area? - Notice the white lines running north-south in the
area. What do they represent? (answer in lab
report) -
- Zoom to the extent of ne_nerrs and turn the layer
back on. Also turn on nerr_watersheds. - For the rest of the exercise you will be looking
at land cover within the watersheds of Great Bay
and Narragansett Bay NERRs. - Turn off nh_nh19930612.img and ma_ma19970623.img,
and close their legends (by clicking the minus
sign next to their name). - Turn on NHnerr_landcov and expand its legend.
41Part 3 Using C-CAP Data to Determine Impervious
Surfaces
The land cover grids were produced in ArcView
3x using the C-CAP Data Handler Extension.
FYI
- Examine C-CAP Data Classifications (contd)
- Turn off the watershed layer so that you can see
the land cover grid. This layer shows just the
land cover within the Great Bay NERR watershed. - Zoom to the NHnerr_landcov layer, and open its
Attribute Table. The attribute table contains
records for each of the land classifications
(Class_names) along with how many pixels are
assigned that classification (Count). Also notice
the Level1 field which is a more generalized set
of land cover classifications. For example,
Level1 classifies the three forest land cover
categories (Deciduous, Evergreen, and Mixed
Forest) into one Forested Land class. - 2. Determine the Percentage of Impervious Surface
in the Great Bay NERR Watershed - You will now find the total area (represented by
pixels) of the watershed, and the area classified
as Developed in order to calculate the percentage
of impervious surface. - In the Attribute table right-click on the Count
field header, and go to Statistics. First, you
are interested in how many pixels make up the
entire watershed scene. That is represented by
the Sum. Jot that number down. ____________
(Total pixels in NHnerr watershed) Close the
Statistics window.
42Part 3 Using C-CAP Data to Determine Impervious
Surfaces
You may have noticed that the color for
selected items is the same as symbol color for .
In the C-CAP data legend. There isnt much.
Present in these land cover scenes so it did not
pose a problem for distinguishing the selected
items. If it had, however, it is possible to
change the Selection color for better contrast
with your layers. To Change the Selection Color,
click Selection gt Options and choose a new
Selection Color
FYI
- 2. Determine the Percentage of Impervious Surface
in the Great Bay NERR Watershed (contd) - In the Attributes window, click Options gt Select
by Attributes. - Create a new selection using the expression
Level1 Developed Land. Click Apply. As you
can see in the Attribute Table, this has selected
those pixels designated as both High and Low
Density Developed. - Close the Select by Attribute window, and move
the Attribute Table so that you can see the areas
selected on the land cover grid. - In the Attribute Table, right-click on Count and
go to Statistics. This time it is only
considering the selected areas, so the Sum in
this case are just those pixels classified as
Developed Land. Jot this number down _________
(Developed Land pixels in Nhnerr watershed) Close
the Statistics window. - To find the percentage of this watershed that has
impervious surfaces divide the Developed Land
pixels by the Total pixels. (A calculator can be
found by clicking on Start at the bottom of your
screen. Start gt Programs gt Accessories gt
Calculator) - ______ of the NHnerr watershed is impervious
surface.
43Part 3 Using C-CAP Data to Determine Impervious
Surfaces
- 3. Determine the Percentage of Impervious Surface
in the Narragansett Bay NERR Watershed and put
this in your lab report. - Follow the same procedures to determine the
impervious surface percentage for the
Narragansett Bay watershed. - Find the sum of all RInerr_landcov pixels
- _________ (Total pixels in RInerr watershed)
- Select Developed Land, and find the sum
- _________ (Developed Land pixels in RInerr
watershed) - Calculate the percentage of impervious surface
- _________ of the RInerr watershed is
impervious - In Part 3 you worked with and became familiar
with C-CAP data. You selected individual land
cover classes and used statistics about those
classes to determine the percentage of impervious
surfaces in NERR watersheds.
44Discussion Overview of Management Applications
Calculate more precise estimates for impervious
surfaces. Consider High Intensity Developed
areas to be 90 impervious, and Low Intensity
Developed areas to be 65 impervious. Does it
drastically change your results? Answer in lab
report
Challenge Exercise
- Which watershed has more impervious surface?
- What implications might this have on the NERR and
the water quality of the bay? - What else could you find out about the watershed
region using C-CAP data? - answer in lab report
- Dont forget the Challenge Exercise!!
45Congratulations! You have completed Exercise
6! Lets quickly review what you did and what
you learned
You began by selecting NERRs in New England, and
then finding the watersheds and counties that
influence those NERRs. By doing this you learned
how to select features based on where they are in
relation to features in other layers. Once you
had the counties that made up these influential
areas, you found and incorporated the
corresponding Census TIGER data. In the process,
you learned not only how to find appropriate
Census data, but how to join tabular data to your
existing shapefiles. From there, you calculated
the 1990-2000 population change for your counties
and used a variety of classification methods to
display population information. This taught you
how to create and calculate new data fields, as
well as getting you familiar with what
classification types work best with different
data.
You then concentrated on one county (Barnstable,
MA) and brought in its census tract and
demographic data. You used this data to create a
map layout using multiple data frames. Each data
frame represented an environmental parameter that
you deemed important to coastal managers. Again,
you gained experience joining tables and using
various classifications and symbology. Finally,
you learned about C-CAP data. You became familiar
with the C-CAP classification scheme, how to
select individual land cover classes, and how to
use the attribute table statistics. Most
importantly, you learned how all of these skills
can and are used in the application of coastal
management!