*** Arc/Info Notes from Hell ***
Get this: Arc cannot handle directories with Capitol letters :)
The EXPORT command in Arc puts out the current arc coverage as a .e00 file.
This file may be compressed if FULL option is taken or not with NONE option.
Either way the .e00 file is an ASCII file! When using ftp to transfer the
file make sure it is in ASCII mode. Likewise when reading the file into
the IBM RISC 6000 using DOSREAD, you must use the '-a' flag to get rid of
IBM's carriage return/line feed combo.
The IMPORT command will read in an Arc ASCII .e00 file. Ex. for county.e00
Arc: import cover county county
^ ^
/ \
(file) county.e00 county (Arc dir)
Once imported the coverages still need to be built.
Arc: build county poly
Arc: build county line
DLG files can be imported into arc using the DLGARC command. From Dave T's
8mm Tape I wrote (un'tar'ed) off the files, then 'mv'ed them to where I
wanted to convert them. I looked in the county dir at the 'prj' (the
projection) to see what it was and noticed the 'y offset' was -4000000.
I had extracted the dlg and found it wasn't offset, so in the following
example for converting the file lstalam.dlg that value is used.
Arc: dlgarc optional lstalam.dlg alam # # 0 -4000000
^^^^^^^^
Note: the CDOT files had projected the files with -4000000, instead of
+4000000. I had to correct this later as I had applied the correction
to the USFWS files. The USFWS files are correct as is - no yshift needed.
Again you must also build the coverage (poly, line/arc, or point) as above.
Arc: build alam
To add the polygon information in the .att file use the following steps.
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >DEFINE ALAM.INF
ITEM NAME>ALAM-ID,4,5,B
ITEM NAME>EW,4,12,F,5
ITEM NAME>NS,4,12,F,5
ITEM NAME>MANAGER,25,25,C
ITEM NAME>OWNER,4,4,C
ITEM NAME>STATUS,4,4,C
ITEM NAME>
ENTER COMMAND >ADD FROM ../lstalam.att
ENTER COMMAND >Q STOP
Arc: joinitem alam.pat alam.inf alam.pat alam-id alam-id
To compensate for the 8 (cany,rang,doug,gran,delt,nucl,dove,cort) which
are in zone 12, reproject them to zone 13.
Arc: project cover cort cort2
Project: output
Project: projection utm
Project: zone 13
Project: units meters
Project: yshift -4000000
Project: parameters
Project: end
To reproject from present (UTM) to Lambert Equal Area (lambert_azimuth).
Arc: project cover county county_lea
Project: output
Project: projection lambert_azimuth
Project: units meters
Project: datum nad83
Project: spheroid grs1980
Project: parameters
radius of the sphere of reference [ 0.00000 ]: 0.0
longitude of center of projection [ 0 0 0.000 ]: -105 30 00
latitude of center of projection [ 0 0 0.000 ]: 39 00 00
false easting (meters) [ 0.00000 ]: 0.0
false northing (meters) [ 0.00000 ]: 0.0
Project: end
For the DCW (Digital Chart of the World), after uploading the arc files
desired and converting the files to lowercase and rebuilding. They need to
be reprojected. Use arc 'describe' to see what the coodinates of the DCW
data is (the Xmin, Xmax, Ymin, Ymax) values.
Arc: build ej32 line
Arc: describe ej32
Arc: info
ENTER COMMAND >DEFINE EJ32.TIC
ITEM NAME>IDTIC,4,5,B
ITEM NAME>XTIC,4,12,F,3
ITEM NAME>YTIC,4,12,F,3
ITEM NAME>
ENTER COMMAND >ADD
IDTIC>1 XTIC>-105.000 (Xmax) YTIC>45.000 (Ymax)
IDTIC>2 -110.000 Xmin 45.000 Ymax
IDTIC>3 -110.000 Xmin 40.000 Ymin
IDTIC>4 -105.000 Xmax 40.000 Ymin
IDTIC>
Arc: project cover ej32 ej32_utm
Project: input
Project: projection geographic
Project: units dd
Project: parameters
Project: output
Project: projection utm
Project: zone 13
Project: units meters
Project: yshift -4000000
Project: parameters
Project: end
To reselect a part of the area (USFS, BLM, and NPS in this case).
Arc: reselect alam alam_sub poly
Reselecting POLYGON features from ALAM to create ALAM_SUB
Enter a logical expression. (Enter a blank line when finished)
>: res owner = 'USFS' or owner = 'BLM' or owner = 'NPS'
>:
Do you wish to re-enter expression (Y/N)? n
Do you wish to enter another expression (Y/N)? n
>: res owner = 'USFS' or owner = 'BLM' or owner = 'NPS'
>: or owner = 'BIA' or owner = 'NBS' or owner = 'NOAA'
>: or owner = 'DOD' or owner = 'PVT'
>: res owner eq 'CDOW' or owner eq 'DOD' or owner eq 'DOE' or owner eq 'FED'
>: or owner eq 'FS' or owner eq 'FWS' or owner eq 'NGL' or owner eq 'NGP'
>: or owner eq 'NHS' or owner eq 'NM' or owner eq 'NPK' or owner eq 'NRA'
>: or owner eq 'NWR' or owner eq 'SCCWPORA' or owner eq 'SFH' or owner eq 'SRA'
>: or owner eq 'CPOR' or owner eq 'SWA' or owner eq 'WILDA'
To view the files, I've been typing this (in part from Freeman's Photo-Index):
Arc: ae { arcedit }
{ ArcEdit bullsh*t }
Arcedit: mape county { mapextent }
Arcedit: display 9999 3 { open a display window }
Arcedit: ec county { edit }
Arcedit: ef arc { editfeature }
Arcedit: de all off arc on { drawenvironment }
Arcedit: draw
Arcedit: bc alam 5 { backcoverage }
{ shows file path, cover # & color # }
Arcedit: be all off arc on { backenvironment }
Arcedit: draw
This will show the alamosa area (in blue-green) on the colo counties (white)
and the bc part can be repeated in differing colors for other layers.
Some other commands to note (from Willis's finger flurry):
Arcedit: &term { set the terminal }
Arcedit: forms
Arcedit: items
----=----=----=----=----=----=----=----=-----=----=----=----=----=----=----=----
Introduction To Geographic Information Systems
Geography 4103/5103
Fall Semester 1993
Instructor: Michael E. Hodgson, Ph.D.
Teaching Assistant: Maggi Kelly
Course Content
There are three primary areas of study in the geographic information
processing realm of geography: remote sensing, cartography, and geographic
information systems. Remote sensing is primarily a data gathering science,
cartography a data mapping science, and geographic information systems a
storage/retrieval and data analysis science. Geographic information
systems (GIS) may be fully regarded as a toolbox of techniques to capture,
transform, store/retrieve, analysis and create cartographic output; so in
some ways covers portions of the disciplines of remote sensing and
cartography. This course in GIS will present to the student the fundamental
methods of digital map data representation, map data capture, map data
analysis, and map output. The "map" is a key modifier to all data in a GIS.
Unlike other data management and analysis systems, a GIS is designed to
operate on mappable data - data with a spatial dimension. A student
successfully completing the course will have the experience with the
necessary tools to conduct his/her own research project using a contemporary
GIS. The topics are organized to lead the student systematically through
The logical steps used in conducting a typical GIS project.
Course Prerequisites
All students should have completed a cartography course, such as Maps and
Mapping of Cartography I. I assume that all students have a fundamental
Knowledge of basic cartographic theory - mappable data, scale,
generalizations, and map projections. Also, each student should be familiar
with fundamental UNIX Operating System commands (or a quick learner).
1) Overview of Geographical Information Systems
Lab #1: Introduction to ArcView, Querying, Features/Attributes
FUNDAMENTALS & VECTOR DATA MODELS
2) Map Projections
Geographic Data Models - Features and Attributes: Vector
Lab #2: Introduction to Arc-Info and Map Projections
3) Databases: Flat-file and Relational Databases
Lab #3: Introduction to Info, Modifying Coverages
4) Map Overlays - Containment
Positional Error: Precision and Accuracy
Lab #4: Map Overlays: Containment
5) Map Overlays - union, intersection, slivers, etc.
Distance Measures, Temporal Dimensions
Lab #5: Polygon Overlay and Distance Computations
6) TIGER & Address Matching
Introduction to Arcplot/Map Composition
Lab #6: Street Address Coverages and Address Matching
7) Sources of Geographic Data
Lab #7: Map Composition
RASTER DATA MODELS
8) Global Positioning Systems
Data Capture
Lab #8: Analog Data Capture
9) Topographic Characteristics: Slope/Aspect, Basins, Streamlines
Surfaces and Raster Data Models: Topographic and Other
Lab #9: Analog Data Capture, Part II
10) Surface Creation: Spatial Interpolation, Isoline-to-Grid
Triangulated Irregular Networks
Lab #10: Introduction to Raster Data Models and Continuous Surfaces
11) Cartographic Modeling/Map Algebra
Landscapes Indices
Lab #11: Map Overlays, Size and Area
12) Distance and Diffusion
Lab #12: Suitability Mapping
14) Lab #13: Distance and Diffusion
15) Modeling of Dynamic Features
Lab #14: Modeling a Dynamic Feature with a Raster Data Model
16) Selected Research Problems: Integration, Modeling, n-d Data Models
----=----=----=----=----
Lab #1: Introduction to ArcView, Features and Attributes
OBJECTIVES
This lab has four objectives: 1) familiarize students with some
Fundamentals of Unix commands, 2) a brief introduction to ArcView,
3) understanding of simple methods of querying the attributes of features,
and 4) creation of a map of the Santa Clara County study area with county
boundaries, transportation routes, and hydrography.
MATERIALS
The Arc-Info coverages you will work with are:
Coverage Name Description
cal_data/CalifStart.av The ArcView file
1:100,000 scale quads
1:24,000 scale quads
County boundaries for California
Hydrography
Transportation Lines
Creating your own Arc-Info subdirectory
Create a subdirectory in your workspace called Arc using the Unix command:
mkdir arc
Change your current location to this subdirectory by:
cd arc
Copy the file named calstart.av to your Arc directory:
cp /home/data/pub/geog4103/pre_delaney/cal_data/CalifStart.av
~yourname/arc
Make sure the file is in there in your Arc directory before proceeding:
dir
Running ArcView (ver. 1)
Run the ArcView program using the following command:
arcview
TASK 1. Displaying a Coverage on Screen
Task: Display the Santa Clara County study area with the county boundaries
in black, the major transportation routes in red and hydrographic features
in black.
How do you display a coverage on screen?
(e.g. county boundaries)
How do you change colors of the displayed coverage?
(e.g. county boundaries in black)
How do you zoom in on a portion of the coverage on screen?
(i.e. Santa Clara County California)
How do you overlay other cartographic features on the Santa Clara County view?
(i.e. hydrography, transportation)
How do you place a title on the map?
TASK 2. Map Querying and Map Measurements
Task: Determine the geographic scope of the Santa Clara County study area in
1) kilometers, and 2) as defined by the number and name of 1:100k and 1:24k
quadrangle map sheets.
How do you query information on the display?
...find attributes of a county?
...point on the screen to find the X-Y coordinates of any point?
How do you display the 1:100k quad sheets on the zoomed-in portion of Santa
Clara County?
How do you display the names of the same quad sheets on the screen?
Task 3. Composing a Hardcopy Map
Task: Create a hardcopy map on the laser printer showing the Santa Clara
County study area with transportation routes and hydrographic features
overlaid. Choose symbology that enables you to differentiate the features
on a B/W laser printer map.
How do you define a subset of the entire coverage that you only want plotted?
How do you plot the map on the laser printer?
Display cover
File - Open - {dc} CalifStart.av
Change display color
{ch} arrow beside feature - Properties...
Legend (note - outlines button depressed) - {dc} orange box
black - Apply
{dc} to close window
Other display features
{c} box to check feature
Zoom In/Out
+ magnifier - {c} on map
Pointer/Info
{c} on object give info window
x,y coodinates
Finger
{c} centers
Dashed Box
window area selection
Only what is in arcview window will print
File - Preferences - Plotting & Encapsulated Postscript -OK
{c} camera button creates .eps
----=----=----=----=----
Lab #2: Introduction to Arc-Info and Map Projections
OBJECTIVES
This lab has three objectives: 1) familiarize students with more
fundamental Unix commands, 2) a brief introduction to Arc-Info and
subsetting and map projection capabilites, and 3) creation of a map of the
Santa Clara County study area with the location of homes damaged by the
Loma Prieta earthquake. You must project one dataset into the same
coordinate system as the other dataset in order to correctly overlay the
maps.
BACKGROUND
The Loma Prieta earthquake (M 7.1) occured on October 17, 1989 at 5:04 pm
Pacific time. The depth of focus was 18.24 km. The Santa Clara county tax
assessor's office has provided you with a digital dataset of the homes that
were damaged in the county. The dataset (i.e. lpdamage.dat) is in the UTM
coordinate system but is an ascii file - you must convert it into a form
suitable for Arc-Info for display and analysis. You also want to plot
background information on the map, such as the county boundaries and
locations of the Special Studies Zones and epicenter of the Loma Prieta
Earthquake.
MATERIALS
The Arc-Info coverages (/home/data/pub/geog4103/pre_delaney) you will
work with are:
Coverage Name Description
usa_2m/pop88c County boundaries for California
cal_data/lpdamage.dat Location of homes damaged by the Loma Prieta
cal_data/sczones Location of Alquist Priolo Zones
Running Arc-Info
Change your current location to the Arc subdirectory by:
cd arc
Run the Arc-Info program using the following command:
arc
TASK 1. Subsetting a Coverage
Task: Create a coverage with only the Santa Clara county area
How do you subset a coverage?
(i.e. only the Santa Clara County boundary)
Arc: reselect /pub/usa_2m/pop88c sc_county poly
>: res state_name eq 'California' and cnty_name eq 'Santa Clara'
>: (cr)
n
n
[Note: This takes a while ... be patient]
TASK 2. Reprojecting a Coverage and Creating a Coverage
Task: Reproject the Santa Clara County boundary created in Task 1 into the
UTM coordinate system.
How do you reproject a coverage?
(i.e. county boundaries)
Arc: project cover sc_county sc_county_utm
Project: output
Project: projection utm
Project: zone 10
Project: unit meters
Project: parameters
Project: end
[Note: the input projection is already known for this file]
Arc: build sc_county_utm
Task: Create a coverage called lprieta depicting the location of of the
epicenter of the Loma Prieta eathquake.
Arc: generate lprieta
Generate: points
ID,X,Y: 1, -121.8897, 37.0333
ID,X,Y: end
Generate: q
[Note: This point is the decimal degree equivalent]
Task: Reproject Loma Prieta point coverage (lprieta) from geographic into
the UTM coordinate system (lprieta_utm).
Arc: project cover lprieta lprieta_utm
Project: input
Project: projection geographic
Project: units dd
Project: parameters
Project: output
Project: projection utm
Project: zone 10
Project: unit meters
Project: parameters
Project: end
[Note: The input specifications are not known so you must tell Arc]
Arc: build lprieta_utm point
[Note: Make sure you use the point option]
Task: Create a point coverage (lpdamage_utm) showing the locations of homes
damaged in Santa Clara County from the ASCII file (lpdamage.dat). The ascii
file is in the form: id, x, y and is in the UTM coordinate system.
Arc: generate lpdamage_utm
Generate: input /pub/geog4103/cal_data/lpdamage.dat
Generate: points
Generate: q
[Note: You will get an unexpected EOF if the last line in the file is
not END - this is OK]
Task: Build the "topology" for the Point Coverage.
Arc: build lpdamage_utm point
Task: Define characteristics of the map projection for this dataset
Arc: projectdefine cover lpdamage_utm
Project: projection utm
Project: unit meters
Project: zone 10
Project: parameters
Arc:
Task 3. Creating a New ArcView
Task: Create a hardcopy map on the laser printer showing the Santa Clara
County study area with the location of homes damaged by the Loma Prieta
earthquake and the boundaries of the major faults.
Task: Create a new arcview file.
arcview
File - Add... - {dc} sc_county_utm
File - Add... - {dc} lprieta_utm
File - Add... - {dc} lpdamage_utm
Windows - New Display
File - Save - santa_clara_map
File - Add - Go To: /pub/geog4103/cal_data - {dc} sczones
TURN IN LIST
Visually examine the Pattern of Homes Damaged in Santa Clara county. Why is
the pattern as it is? In other words, why is the pattern not uniformly
distributed throughout the county? _______________________________________
Turn in you B/W map of the damaged homes in Santa Clara county, the location
of the Special Studies Zones, and the location of the Loma Prieta epicenter.
----=----=----=----=----
Lab #3: Introduction to Info, Modifying Coverages
OBJECTIVES
This lab has several objectives. First, you will create an Arc coverage of
points where the spatial information exists in an ascii data file. Next, you
will learn how to create an INFO file - a database of descriptive information
about point locations. You will modify an INFO file and create new variables.
Finally, you learn how to relate the descriptive information in the INFO file
to the spatial information in the ARC file; thus, you will have created a
geographic database.
BACKGROUND
You would like to be able to answer the following questions:
Is there a statistically significant difference in the mean distance between
homes insured and those uninsured? ...before the Loma Prieta earthquake?
...after the Loma Prieta earthquake?
However, you must actually compute the distances between each home and the
Special Studies Zones (we have not done this in lab yet and will not until
later). For this lab create a map that shows the insurance status of each
home before the Loma Prieta earthquake, after the Loma Prieta earthquake,
and those individuals that changed insurance status (those who purchased
insurance following the earthquake). You can visually analyze the map and
try to answer the questions above.
For data you have been given the random list of homeowners surveyed before
and after the Loma Prieta earthquake in Santa Clara County. The surveyed
homeowners were randomly selected from the tax assessor's office list in
the county. A mail survey was used to extract insurance status,
socioeconomic, and perceptual information from each homeowner. The spatial
location of each homeowner was determined by geocoding street address
locations with TIGER data (more about the geocoding process in a later lab).
MATERIALS
The Arc-Info coverages you will work with are:
Coverage Name Description
sc_county_utm Santa Clara County boundary (from lab #2)
cal_data/sczones Location of Alquist Priolo Zones
cal_data/surxy89.dat Location of each home surveyed (UTM coords)
cal_data/scins89.dat Insurance status of each homeowner before
(-1=no response, 1=insured, 2=not insured)
cal_data/scins89.dat Insurance status of each homeowner after
(-1=no response, 1=insured, 2=not insured)
TASK 1. Creating a Point Coverage (survey) from an ASCII File (surxy89.dat)
Task: Use the Generate command to create the file and input data
Arc: generate survey
Generate: input /pub/geog4103/cal_data/surxy89.dat
Generate: points
Generate: q
[Note: You will get an unexpected EOF if the last line in the file is
not END - this is OK]
Task: Build the "topology" for the Point Coverage:
Arc: build survey point
Arc: projectdefine cover survey
Project: projection utm
Project: unit meters
Project: zone 10
Project: parameters
Task: Check to see if the projection information is there:
Arc: describe survey
TASK 2. Creating an attribute file for the existing Point Coverage
Task: Using INFO to examine the items in a Coverage Database:
[Note: Make sure the Caps Lock is on when in INFO]
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >SELECT SURVEY.PAT
ENTER COMMAND >ITEMS
ENTER COMMAND >LIST
[Note: Notice the width, type for each item name and there is no spatial info]
Task: Create two INFO databases of the "Insurance Status of Homeowners"
ENTER COMMAND >DEFINE SURVEY89.INF
ITEM NAME>SURVEY-ID,4,5,B
ITEM NAME>INSURE-STATUS89,4,4,N,1
ITEM NAME>
ENTER COMMAND >ADD FROM /pub/geog4103/cal_data/scins89.dat
Repeat for the insurance status in 1990 but put in survey90.inf
ENTER COMMAND >Q
ENTER USER NAME>STOP
Task: Join the 1989 attribute file with the point coverage
Arc: joinitem survey.pat survey89.inf survey.pat
survey-id survey-id ordered
Use INFO to reexamine the items in the Coverage Database:
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >SEL SURVEY.PAT
ENTER COMMAND >ITEMS
ENTER COMMAND >LIST
[Note: Values of 0 are for those obs. that we did not have a value for
insurance status - they did not respond to the survey]
ENTER COMMAND >Q
ENTER USER NAME>STOP
Task: Join the 1990 attribute file with the point coverage
Arc: joinitem survey.pat survey90.inf survey.pat
survey-id insure-status89 ordered
Task: Delete the Info Databases you created (but not the one related):
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >SELECT SURVEY89.INF
ENTER COMMAND >DELETE SURVEY89.INF
ENTER COMMAND >SEL SURVEY90.INF
ENTER COMMAND >DELE SURVEY90.INF
ENTER COMMAND >Q STOP
Task: Create an Item that indicates the change in insurance status
Arc: additem survey.pat survey.pat insure-change 2 2 I
If 1989 status = 2 and 1990 status = 1 then the homeowner changed to INSURED
If 1989 status = 1 and 1990 status = 2 then the homeowner changed to UNINSURED
If 1989 status = 1 and 1990 status = 1 then the homeowner changed to INSURED
If 1989 status = 2 and 1990 status = 2 then the homeowner changed to UNINSURED
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >SEL SURVEY.PAT
ENTER COMMAND >RESELECT INSURE-STATUS89 = 2 AND INSURE-STATUS90 = 1
ENTER COMMAND >CALC INSURE-CHANGE = 1
ENTER COMMAND >ASELECT
ENTER COMMAND >RESEL INSURE-STATUS89 = 1 AND INSURE-STATUS90 = 2
ENTER COMMAND >CALC INSURE-CHANGE = 2
ENTER COMMAND >ASEL
ENTER COMMAND >RESEL INSURE-STATUS89 = 1 AND INSURE-STATUS90 = 1
ENTER COMMAND >CALC INSURE-CHANGE = 3
ENTER COMMAND >ASEL
ENTER COMMAND >RESEL INSURE-STATUS89 = 2 AND INSURE-STATUS90 = 2
ENTER COMMAND >CALC INSURE-CHANGE = 4
ENTER COMMAND >Q STOP
TASK 3. Obtaining Descriptive Statistics for an Info file
Arc: statistics survey.pat survey89.sta insure-status89
Statistics: sum insure-status89
(cr)
N
N
list survey89.sta (frequency for each value)
[Note: The frequency for each value of "insure-status89" will be listed]
Do the same for the 1990 insurance status and the change in insurance status
TASK 4. Adding the Surveyed Homeowners Data to an Existing ArcView
Task: Using information from the previous labs, add the surveyed theme to your
existing ArcView and create the appropriate maps.
TURN IN LIST
How many responded to the survey before Loma Prieta? ___
How many responded to the survey after Loma Prieta? ___
Of the homes responding before Loma Prieta,
...how many were insured? ___
...how many were uninsured? ___
Of the homes responding after Loma Prieta,
...how many were insured? ___
...how many were uninsured? ___
How many uninsured homeowners before Loma Prieta purchased insurance after
Loma Prieta? ___
Visually examine the Insurance Status of the surveyed homeowners in Santa
Clara County. Are those homeowners who carry earthquake insurance closer
to the San Andreas Fault than those who do not? ______
Turn in you B/W map of the insured/uninsured homeowners in Santa Clara
county before Loma Prieta and a B/W map of the same after Loma Prieta,
and a map of those homeowners who changed insurance status.
----=----=----=----=----
Lab #4: Map Overlays: Containment
OBJECTIVES
This lab will introduce you to the concept of map overlays - a coverage of
points and a coverage of polygons. Your objective is to 1) determine the
number of surveyed homes (and insurance status) located in the Special
Studies Zones in Santa Clara County, California, and 2) determine the number
of surveyed homes (and insurance status) located in the 100-year flood zones
in the municipio of San German, Puerto Rico.
BACKGROUND
You would like to be able to answer the following questions:
Is there a difference in the insurance status between those homeowners who
live in a hazardous zone (e.g. Alquist Prioli Zone or 100-year flood zone)
verses those who live outside of the zone?
For data you have the random list of homeowners surveyed before and after
the Loma Prieta earthquake in Santa Clara County (lab #3). Also provided is
a dataset used in a survey of homeowners in the municipio of San German,
Puerto Rico. Similar to the California studies, these homeowners were asked
questions about their socioeconomic characteristics and insurance and thier
attitudes and behavior towards natural hazards.
MATERIALS
The Arc coverages you will work with are:
Coverage Name Description
sc_county_utm Santa Clara County boundary (from Lab #2)
cal_data/sczones Location of Alquist Priolo Zones
survey Coverage of homes surveyed and their
insurance status (from Lab #3)
pr_data/prdemog/s_munic San German municipio boundary
pr_data/prflood/s_flood Coverage of 100yr flood zones in San German
pr_data/prdemog/sg_surveyxy.dat Location of homes surveyed in Puerto Rico
in 1990.
pr_data/prdemog/sg_surveyins.dat ascii file of surveyed homeowners in San
German and the flood insurance status.
(1=insured, 2=not insured)
TASK 1. Determine Homes in the Special Studies Zones of Santa Clara County
Task: Intersect the coverage of surveyed homes of Santa Clara County with
the Special Studies Zones.
Arc: identity survey /pub/geog4103/cal_data/sczones scsurover point
Arc: list scsurover.pat
[Note: There is a new item called ZONE_NAME]
Task: Compute frequencies of the surveyed home location characteristics
Arc: frequency scsurover.pat scsurover.frq
Enter the 1st item: zone_name
Enter the 2nd item: end
Enter the 1st item: end
Arc: list scsurover.frq
Task: Compute frequencies of the surveyed home locational & and insurance
status characteristics
Arc: frequency scsurover.pat scsurinsover.frq
Enter the 1st item: zone_name
Enter the 2nd item: insure-change
Enter the 3rd item: end
Enter the 1st item: end
Arc: list scsurinsover.frq
TASK 2. Compute the percentage of the Santa Clara County covered by Special
Studies Zones
Task: Using a polygon overlay operation, determine the percentage of the
county that is covered by Special Studies Zones.
Arc: intersect cal_data/sczones sc_county_utm sczoneint poly
Arc: statistics sczoneint.pat sczoneint.sta area
Statistics: sum area
Statistics: (cr)
Do you wish to re-enter expression (Y/N)? N
Do you wish to enter another expression (Y/N)? N
Arc: list sczoneint.sta
Task: Using ArcView, create a map showing the locations of the surveyed
homeowners and only the portions of the Special Studies Zones that are
within Santa Clara County. You should "add" the sczoneint to the ArcView.
TASK 3. Create a Map of the Surveyed Homes in San German
Task: Create a point coverage of home locations and their characteristics
from an ASCII file. You will have to inport the file containing the id, x, y
locations of each surveyed homeowner into and Arc coverage using the generate
command. You did a similar task in a previous lab.
Task: Use ArcView to create a map of the surveyed homeowners showing the
insured and uninsured, the municipio boundary of San German, and the 100-year
flood zones in the area. For a nicer graphic, you might do the polygon
overlay in Task 4 first and just show those flood zones that are within the
municipio of San German. You have conducted a similar exercise before for
the Santa Clara county study. You must start in ArcView and create a "new"
view.
TASK 4. Determine the Locational Characteristics of San German Homes
Task: Determine the locational characteristics of the surveyed homeowners in
San German with respect to the 100-year flood zone in the municipio. Look
at the "Turn in list" to determine the kind of characteristics you will need
to measure.
TASK 5. Compute the percentage of San German municipio covered by 100-year
Flood Zones
Task: Using a polygon overlay operation, determine the percentage of the
municipio that is covered by 100-year flood zones.
TURN IN LIST
Santa Clara County, CA Dataset
# of homes inside Special Studies Zone: _____
in San Andreas Zone: ___(insured) ___(not insured)
in Hayward Zone: ___(insured) ___(not insured)
in Calevaras Zone: ___(insured) ___(not insured)
# of homes inside Special Studies Zone: _____
Percentage of the County contained in Special Studies Zones: ___%
San German, Puerto Rico Dataset
# of homes inside 100-year flood zone: _____
# of homes inside 100-year flood zone AND: ___(insured) ___(not insured)
# of homes outside 100-year flood zone: _____
# of homes outside 100-year flood zone AND: ___(insured) ___(not insured)
Percentage of the municipio covered by 100-year flood zones: ___%
Also turn in
1) your map for San German municipio.
2) your map of Santa Clara County with only the portion of the Special
Studies Zone in Santa Clara County
----=----=----=----=----
Lab #5: Polygon Overlay and Distance Computations
OBJECTIVES
This lab will introduce you to the concept of map overlay and measuring
distances on maps - points, lines, and area data. Your objectives are to
1) dissagregate the population of a hypothetical set of countries to a river
basin and 2) determine the distances of characteristics of surveyed homes
with respect to the Special Studies Zones in Santa Clara County, California.
MATERIALS
The Arc coverages you will work with are:
Coverage Name Description
cal_data/aggbas.dat Arcs for Basin coverage
cal_data/aggbasp.dat Label Points for Basin coverage
cal_data/aggcou.dat Arcs for County coverage
cal_data/aggcoup.dat Label Points for County coverage
survey Surveyed homeowners w/insurance status
cal_data/sczones Coverage of SSZs in the San Francisco Bay
TASK 1. Compute the Population for Each Drainage Basin
Task: Create cover of "basins" from ASCII file (aggbas.dat).
Arc: generate basins
Generate: input /pub/geog4103/cal_data/aggbas.dat
Generate: lines
Generate: input /pub/geog4103/cal_data/aggbasp.dat
Generate: points
Generate: q
Arc: build basins
Task: Create the coverage of "counties" from the ascii file (aggbas.dat and
aggcoup.dat). Use a similar sequence of commands as above. Be sure to
build topology.
Task: Create info file (counties.inf) of population for each county. Get
into info and create the items COUNTIES-ID (width=4, output width=5, and
type=B), POP_COU (width=4, output width=8, type=F, and decimal places=0),
and POP_AREA (width=4, output width=12, type=F, and decimal places=3). Use
the ADD command to enter the population for each of the counties-id below:
COUNTIES-ID POP COU
1 45000
2 28000
3 8000
4 5000
Arc: info
ENTER COMMAND >DEFINE COUNTIES.INF
ITEM NAME>COUNTIES-ID,4,5,B
ITEM NAME>POP_COU,4,8,F,0
ITEM NAME>POP_AREA,4,12,F,3
ITEM NAME>
ENTER COMMAND >ADD
COUNTIES-ID> 1 2 3 4
POP_COU> 45000 28000 8000 5000
POP_AREA> (cr)
COUNTIES-ID> (cr)
ENTER COMMAND >Q STOP
Task: Now compute the population per area in Info. List the values to make
sure all is well.
Task: Join the new attribute file and use info to compute the population per
unit area.
Arc: joinitem counties.pat counties.inf counties.pat counties-id
counties-id
ENTER COMMAND >SEL COUNTIES.PAT
ENTER COMMAND >CALC POP_AREA = POP_COU / AREA
ENTER COMMAND >LIST POP_AREA
Task: Compute the intersection of the drainage basins with the counties.
Arc: intersect basins counties bascou poly
Task: Create new item (POP_BC) representing the population per basin-county
subbasins (width=4, output width=12, type=F, and decimal places=3). Derive
the population in each of these subbasins using the following Info command:
CALC POP_BC = POP_AREA * AREA
Arc: additem bascou.pat bascou.pat pop_bc 4 12 F 3
ENTER COMMAND >SEL BASCOU.PAT
ENTER COMMAND >CALC POP_BC = POP_AREA * AREA
Task: Aggregate the population to the basin for each county portion.
Arc: statistics bascou.pat basins.inf basins-id
Statistics: sum pop_bc
(cr)
n
n
Arc: list basins.inf
Task: Join each basin agg_pop to the basins cover
Arc: joinitem basins.inf basins.pat basins.pat basins-id basins-id
TASK 2. Determine Distance of Each Damaged Home from San Andreas Fault Zone
Task: Create a coverage with only the San Andreas Fault polygons. You
should use the Arc Reselect command to pick out all the polygons with the
'San Andreas name.
Task: Determine the distance from each home to the San Andreas Fault Zone
using the near command.
Task: Relate the distance file to the survey.pat file using the joinitem
command.
Task: Now find those inside the San Andreas Fault Zone and recode their
distance to 0.0 using Info.
Task: Compute the mean and standard deviation in distance from the San
Andreas Fault Zone for those not insured, always-insured, and the new
insurance purchasers after the Loma Prieta Earthquake using statistics.
Task: Test for significant differences between these groups using T-Tests
- Arc/Info does not have statistical analysis functions so you will have
to do this by hand (or export the files to a statistical analysis package.
mean(X1) - mean(X2)
t = ---------------------------------------
( S1^2/(N1 - 1) + S2^2/(N2 - 2) )^1/2
S^2 = the variance, the standard deviation squared
N = number of observations
the degrees of freedom (i.e. df) are:
df = (N1 + N2) -2
TURN IN LIST
Polygon Overlay Problem
What is the population of Basin #10? _____
Distances for Santa Clara County Problem
Average distance of damaged homes from SSZ: ______km
(when inside homes are 0.0m away from SSZ)
Average distance of surveyed homes from SSZ: ______km
(when inside homes are 0.0m away from SSZ)
Distance from the San Andreas Fault Zone
Is there a significant difference between the average distance of homes
from the San Andreas Fault that were insured and those that are uninsured
after Loma Prieta? _____ (Show your work, including significant levels).
Null hypothesis: Mean Distance(insured) = Mean Distance(uninsured)
Is there a significant difference between the average distance of uninsured
versus new insurance purchasers from San Andreas Fault Zone? ____ (Show
your work, including significant levels).
Null hypothesis: Mean Distance(uninsured) = Mean Distance(newly insured)
----=----=----=----=----
Lab #6: Street Address Coverages and Address Matching
OBJECTIVES
This lab will introduce you to the concept of TIGER files and address
matching. Your objectives are to 1) geocode the GIS student residences and
compute summary statistics. You will also use your new knowledge of Arcplot
to create maps of the Santa Clara County and Boulder, CO study area.
MATERIALS
The Arc coverages you will work with are:
Coverage Name Description
tiger/boutig_utm TIGER line and address coverage
tiger/gisclass.dat Address locations of GIS students
TASK 1. Geocode Your Residence
Task: Create an address coverage with one observation - your home.
Get into Info and create a file called myadd.inf with 4 items:
Description INFO Definition
House Number HNUM,4,5,I
Street Name SNAME,25,25,C
Street Sufix SSUF,10,10,C
Your Name OWNER,15,15,C
ENTER COMMAND >DEFINE MYADD.INF
ITEM NAME>HNUM,4,5,I
ITEM NAME>SNAME,25,25,C
ITEM NAME>SSUF,10,10,C
ITEM NAME>OWNER,15,15,C
ITEM NAME>
Task: Use the ADD command to enter the information for your residence.
ENTER COMMAND >ADD
HNUM>{House number}
SNAME>{Street name}
SSUF>{Street suffix}
OWNER>{Ur name}
2
HNUM>
ENTER COMMAND >Q STOP
Task: Parse the address file to create a new itme called address
Arc: addressparse myadd.inf address 1
Enter the 1st item: HNUM
Enter the 2nd item: SNAME
Enter the 3rd item: SSUF
Enter the 4th item:
Done entering item names (Y/N)? y
Do you wish to use the above items (Y/N)? y
Task: Geocode your residence location with the addressmatch command
Arc: addressmatch myadd.inf address /pub/geog4103/tiger/boutig_utm
myadd 20
TASK 2. Geocode all the GIS Student Residences
Task: Create an address coverage with the address of each student. An ASCII
file has been created for you containing the name, address, and city_state
for each student in the GIS class. You should examine the file
(gisclass.dat) to see the format of it (i.e. commas, quote, etc.). Then
create an info file with three items of proper width and type character.
Use the add from option in info to import the data in the ascii file
directly into the info file.
Task: Geocode the GIS class residences. Some of the residences will not
correctly match. You should look at the gisclass.rej file in info and
examine the addresses to discern why some matched and some did not.
Task: Determine the UTM coordinates of the Guggenheim Geography Department.
Task: Use the Geography Department location to answer the questions on the
next page.
TASK 3. Create a map of the Boulder Area with the Student Locations using
Arcplot. The type of each linear feature (i.e. arc) in the boutig_utm
coverage is listed below:
Type Description
A Roads
B Railroad
C Pipeline, transmission lines, etc.
D Special Transportation (Transportation terminal, airport)
E Other Physical Features
F Boundaries (Zip, Statistical Boundaries)
H Hydrographic Features
TASK 4. Create a map of the Surveyed Homes in Santa Clara County with Arcplot
TURN IN LIST
Your Residence
What is the UTM coordinates for your residence? __________E __________N
Student Residences
How many student residences correctly matched? ____
How many student residences did not correctly match? ____
List the students names whose residence would not match:
__________ __________ __________
What is the UTM coordinates of the Guggenhiem Geography Department?
__________E __________N
Of the students whose address matched, which student lives farther (crow fly
distance) from the Geography Department (precisely using the computer?)
Student Name: ________________ Distance from Guggenheim _______meters
Of the students whose address matched, what is the average travel distance
(crow fly distance) from the Geography Department? _______meters
Turn in a map of the Boulder area (you decide the spatial coverage) showing
the locations of all geocoded GIS students (using Arcplot).
Turn in a map of the Surveyed homeowners, Special Studies Zones, and Santa
Clara County Boundary (using Arcplot).
----=----=----=----=----
Lab #7: Map Composition
OBJECTIVES
This lab will introduce you to the concept of using Arcplot to keep a map
composition. By creating a map through map composition, you may interactively
manipulate the map "elements", save the map composition, and edit the map
composition later without retyping all the commands.
MATERIALS
The Arc coverages you will work with are:
Coverage Name Description
cal_data/sczones Fault zones (SSZs) for Santa Clara County
tiger/gisclass.dat Address locations of GIS students
TASK 1. Beginning the Map Composition
Arcplot: display 9999 3
Arcplot: display resolution 600
Arcplot: map my_map
Arcplot: pagesize 11.0 8.5
Arcplot: units page
Arcplot: shadetype color
Arcplot: shadecolor white
Arcplot: patch [show maplimits]
Arcplot: mape sc_county_utm
Arcplot: linecolor rgb 128 128 128
Arcplot: shadecolor rgb 200 200 200
Arcplot: shadeput 1
Arcplot: arcs sc_county_utm
Arcplot: polygonshades /pub/geog4103/cal_data/sczones 2
Arcplot: linecolor black
Arcplot: polygons /pub/geog4103/cal_data/sczones
Arcplot: minfo
Arcplot: mselect 3
Arcplot: mdelete
Arcplot: mfresh
Arcplot: q
Arcplot: show display resolution
Arcplot: display resolution 600
Arcplot: pagesize 11.0 8.5
Arcplot: map my_map
Arcplot: mselect * {use cursor to select - 9 to delete boundaries}
Arcplot: mdelete
Arcplot: mfresh
Arcplot: mselect * {use cursor to select - 9 to delete fill}
Arcplot: mape sc_county_utm
Arcplot: shadecolor rgb 200 200 200
Arcplot: shadeput 1
Arcplot: polyshades sczoneint 1
Arcplot: linecolor black
Arcplot: polygons sczoneint
Arcplot: move * {use cursor to select area for text}
Arcplot: textcolor black
Arcplot: text 'My Map'
Arcplot: mselect * {select text w/left button}
Arcplot: mmove * {left button lower left of text - right place}
Task: Plotting a map composition
Arcplot: display 1040 1
Enter Output Filename: my_map.gra
Arcplot: plot my_map
Arcplot: q
Arc: rotateplot my_map.gra my_map_90.gra
Arc: arcplot
Arcplot: display 1040 2
Enter Output Filename: my_map.eps
Arcplot: display resolution 600
Arcplot: pagesize 8.5 11 {..}
Arcplot: plot my_map_90.gra
Arcplot: q
Arc: &sys lpr my_map.eps
Other Map Composition Commands
Arcplot: mfresh
Arcplot: mselect *
Arcplot: mselect all
Arcplot: mfit *
Arcplot: mgroup *
Arcplot: mmove *
Arcplot: mscale sf
----=----=----=----=----
Lab #8: Analog Data Capture
OBJECTIVES
This lab will introduce you to the concept of using Arc/Info to capture data
from a map. You will go through the process of preparing the maps, digitizing
the features, editing the features, and transforming the coordinates. In the
next lab, you will finish, correct the problems, and edgematch your coverages
to produce a "seamless" database.
MATERIALS
You will need four maps. There are two themes you will digitize -
hydrography and watersheds. Each theme has an east and west map portion.
TASK 1. Prepare you maps
Task: Mark the locations of nodes at difficult locations, such as arcs
intersecting at small angles or a polygon boundary closing on itself. Label
the locations of the interior label points for each polygon. Label the tic
locations.
TASK 2. Digitize Each Map Portion
Task: The following dialogue is how to digitize the western map of hydrography.
Task: Set up the digitizing tablet for Arc/Info. You will enter the
configuration menu, retrieve the internal stored configuration for Arc/Info,
and exit the configuration menu in three steps.
1) Using the puck, click on the "config" option in the tablet's upper left
2) Click on the "restore 3" option in the tablet's upper left
3) Click on the "config" option again
Task: Digitize the tic marks
Arc: ae
Arcedit: &station dig
Arcedit: coo dig
Arcedit: create hydro_w
For each tic location, use the keypad on the puck to enter the tic id #,
followed by the asterisk (use the A button), and then position the puck over
the tic and digitize using the "2" button. The order of entering tics is
unimportant, however, you must be sure to correctly associate a tic id with
its location.
Task: Digitize the bounding box
Digitize the corners of the boundary using the A button, first the lower
left corner of the map followed by the upper right corner.
Arcedit: editf arc
Arcedit: add
Digitize all the arcs using the "2" button to begin an arc, the "1" button
for all verticies in the arc, and the "2" button to end the arc. Quit the
add process using the "9" button on the puck.
Task: Now digitize the eastern portion of the hydrography theme (hydro_e)
using similar steps as above.
Arcedit: save
Arcedit: q
TASK 3. Create Tic Transformation Coverages and Transform
Task: Now create a cover with the UTM coordinates associated with tics.
Arc: create hydro_e_utm
Arc: create hydro_w_utm
Arc: info
ENTER COMMAND >SEL HYDRO_W_UTM.TIC
ENTER COMMAND >ADD
1
IDTIC> 1
XTIC> 440000
YTIC> 4414000
2
IDTIC> 2
XTIC> 443000
YTIC> 4414000
3
IDTIC> 5
XTIC> 443000
YTIC> 4418000
4
IDTIC> 6
XTIC> 440000
YTIC> 4418000
5
IDTIC>
ENTER COMMAND >LI
Task : Use Info and go through a similar procedure to enter the UTM
coordinates for the eastern hydrography theme.
Task: Transform digitizer coordinates to UTM coordinates for each map.
Arc: transform hydro_e hydro_e_utm
Arc: transform hydro_w hydro_w_utm
TASK 4: Clean and Edit Coverages
Arc: clean hydro_e_utm hydro_e_utm # # line
Arc: clean hydro_w_utm hydro_w_utm # # line
Arc: ae
Arcedit: &station dig
Arcedit: mape "cover"
Arcedit: drawe arcs node errors
Arcedit: edit "cover"
Arcedit: draw
Arcedit: editf arcs
Arcedit: coo cursor
Arcedit: intersectarcs all
At this point it is easiest to edit using the cursor, and the "zoom/pan"
menu at the upper left corner of the screen. You should "create" a zoom
window and select an area surrounding a node error.
Methods for correcting dangling nodes:
1. Overshoot: this is the easiest on to correct.
Select the overshoot from your zoomed window using "sel"
Once selected, it should turn yellow. If not, select it again.
Type "delete". The arc disappears and so does the node error symbol.
2. Undershoots.
Select the undershoot.
Type "extend"
Locate the from point and to point (you will be prompted to do this)
The arc will be extended until it meets a line.
3. Misplaced lines:
Select the line.
Type "move"
Locate the from node and to node. The arc will move as requested.
After editing, quit and clean the coverages again.
TASK 5. Digitize the Watershed Coverages
Following procedures similar to the ones above, digitize the watersheds on
the eastern and western maps including the map boundaries. With the
watersheds you will be explicitly identifying the polygon label points
(for the alpine lakes you just took the default.)
After digitizing the watershed boundaries type,
Arcedit: ef labels
Arcedit: add
Enter and "8" here to get the digitizer options
Enter a "1" if you need to begin at a user-id other than "1".
Locate your label points with the digitizer, making sure that you have the
appropriate User-ID. Enter a "9" to quit.
When you clean the watershed coverages, you must use the "poly" option:
Arc: clean water_e_utm water_e_utm # # poly
Arc: clean water_w_utm water_w_utm # # poly
Task: you must now edit the problems with the watershed coverage. These
errors will be primarily noderrors.
TURN IN
What is the surface area of lake _________? ______hectares
What id the total surface area of the alpine lakes? ______hectares
Determine the frequency and surface area of lakes in each watershed:
Watershed # Lakes Surface Area (hectares)
_____ _____
_____ _____
Overlay the hydrography features and watershed boundaries. Examine the
result and comment on your ability to digitize these features (some of
which should coincide). What are the different factors that may contribute
to the mismatch? _________________________________________________________
----=----=----=----=----
Lab #9: Analog Data Capture, Part II
OBJECTIVES
This lab will finish the process editing the features and edgematching your
coverages to produce a "seamless" database.
MATERIALS
You will need the same four maps of the eastern and western portions of the
hydrography and watersheds.
TASKS
You should now have four coverages - hydro_e_utm, hydro_w_utm, water_e_utm,
water_w_utm. These should be line coverages. In this lab we will join the
files, and overlay them.
1. Add boundary to the water coverages, and then edit the file.
2. Join the hydro coverages.
3. Join the water coverages.
4. Check label errors for the watershed cover.
5. Conduct overlay processes.
TASK 1. Add boundary and edit
Arc: ae
Arcedit: &station dig
Arcedit: coo cursor
Arcedit: mape water_e_utm
Arcedit: ec water_e_utm
Arcedit: ef arc
Arcedit: de all
Arcedit: draw
Arcedit: intersectarcs all
Arcedit: add
Add arcs around the study area, framing it.
Arcedit: save
Arcedit: q
Arc: clean water_e water_e # # line
Do the same for the water_w_utm cover.
In Arcedit, check again for any node errors, and delete them.
TASK 2. Link the hydro coverages using the following commands:
Arc: ae
Arcedit: snapcover hydro_w_utm
Arcedit: linkfeatures node node
Arcedit: backc hydro_w_utm
Arcedit: limitautolink box {delimit the area where links will be made}
Arcedit: snapping first * {delimit circle size the links are made in}
Arcedit: ef link
Arcedit: autolink
[Note: The links will appear in green]
Zoom into the links using the "Zoom/Pan" menu, and examine them. There may be misplaced links. You will have to edit these.
Arcedit: sel many
Arcedit: delete
When all of the links are satisfactory, continue:
Arcedit: limitadjust box
[Note: A green box is drawn around the adjust area]
Arcedit: adjust
Arcedit: sel all
Arcedit: delete
Arcedit: save hyd_e_adj
Arcedit: q
Now you will append the two coverages together using the links that were
established in the Arcedit portion.
Arc: append hydro
Enter the 1st coverage: hydro_w_utm
Enter the 2nd coverage: hyd_e_adj
Enter the 3rd coverage:
Done entering coverage names (Y/N)? y
Do you wish to use the above coverages (Y/N)? y
Arc: clean hydro hydro # # line
For the hydro cover we will let Arc add polygon labels:
Arc: build hydro
Arc: createlabels hydro
You should also retain a line coverage of the hydro, call it rivers
Arc: clean hydro rivers # # line {retain river lines copy}
TASK 3. Join water covers in the same fashion as the hydro covers.
Clean each with the clean # # line option.
TASK 4. Since we have added labels, we have to check for label errors:
Arc: labelerrors watershed
Polygon 1 has 0 label points.
Polygon 2 has 2 label points.
Label User ID: 6
Label User ID: 6
Remember the only polygon that can have no label points is polygon #1, which
is the "universal polygon"
In Arcedit you can delete the labels that are redundant:
Arc: ae
Arcedit: mape watershed
Arcedit: de all
Arcedit: ec watershed
Arcedit: de label ids
Arcedit: draw
Arcedit: ef labels
Arcedit: sel many
Arcedit: dele
Arcedit: save
Arcedit: q
Arc: build watershed
Arc: labelerrors watershed
You should only have one polygon with 0 label points: Polygon 1
Now we can overlay the coverages.
We have: river (line topology)
hydro (polygon topology)
watershed (polygon topology)
TASK 5. Overlay your two coverages in Arcedit:
Arc: ae
Arcedit: mape hydro
Arcedit: ec watershed
Arcedit: de arcs labels ids
Arcedit: bc hydro 4
Arcedit: be arcs labels ids
Arcedit: draw
Compare the lines, thinking about what might account for the differences.
TURN IN
What is the total surface area of the Arapaho Lakes? ______hectares
What is the total surface area of all the alpine lakes? ______hectares
Determine the frequency and surface area of lakes in each watershed:
Watershed # Lakes Surface Area (hectares)
0 _____ _____
2 _____ _____
3 _____ _____
5 _____ _____
6 _____ _____
Overlay the hydrography features and watershed boundaries. Examine the result
and comment on your ability to digitize these features (some of which should
coincide). What are the different factors that may contribute to the
mismatch? __________________________________________________________________
----=----=----=----=----
Lab #10: Introduction to Raster Data Models and Continuous Surfaces
OBJECTIVES
This lab will introduce you to the concept of working with geographic data
represented by a raster data model. The data you will work with are three
continuous elevation surfaces - a contour dataset you will be givien, a
contour map you will digitize, and the USGS derived East Portal 1:24,000
topographic quadrangle.
MATERIALS
The Arc coverages you will work with are:
Coverage Name Description
dem/epor_dem.gis DEM of the "East Portal Quad" in ERDAS format
contour3.e00 Coverage of contour lines in Arc/Info "export" format
[Note: In Arc, you can find the syntax for a command by simply typing in the
command without arguements. In Grid, you must type: usage "command". For
example, if you wanted to know the use of the command "hillshade", type
usage hillshade.]
TASK 1. Digitize Contour Map
Task: AutoCAD Users - Collect your contour data
If using AutoCAD, digitize all your contours as 3-D polyline features but
assign each line feature an "elevation" value that is the contour line
elevation. Create a dxfout file with the appropriate number of digits
precision (e.g. 1 for UTM)
Task: Convert AutoCAD file into Arc form
Arc: dxfarc contour.dxf contour
Enter the 1st layer and options: 0 ARCS
Enter the 2nd layer and options: end
Do you wish to use the above layers and options (Y/N)? y
The dxfarc command will create an arc coverage and an .acode info file. The
.acode info file will contain the elevation attribute for each arc (i.e. dxf-
elevation).
Task: Build the topology for the arcs (i.e. the contour lines) with the
"line" option.
Arc: build contour line
Task: Join .acode file with the arc coverage
Arc: joinitem contour.acode contour.aat contour.aat contour-id
contour-id
Task: Arc/Info Users - Collect your contour data
Digitize all your contours as arcs. Now add an item to the coverage called
elevation that is a floating-point value. Go back into arcedit and
interactively select each contour and "calc" its elevation value. Be sure
to build the topology after you are finished.
== Basic setup for digitizing contour lines ==
Arcedit: &station dig
Arcedit: create contour
...enter tics and bounding area...
Arcedit: ef arcs
Arcedit: add
Arcedit: save
Arcedit: q
Arc: clean contour contour # # line
== End section for digitizing contour lines ==
Arc: additem contour.aat contour.aat elevation 4 12 F
Arc: ae
Arcedit: ec contour
Arcedit: de arcs
Arcedit: draw
Arcedit: ef arcs
Arcedit: sel
...point to the feature. Enter point (from digitizer)...
Arcedit: calc elevation = 2800 {example, repeat for all}
Task: Make sure you have given all the contour lines an appropriate
elevation value.
Arcedit: sel all
Arcedit: list
TASK 2. Contour-to-Grid Conversion
For the Lab Session use contour3 and contin3 for all the examples with the
already created contour lines. You will have to come back and digitize
your own contour lines later.
From your directory, import the coverage that is in "export" form:
Arc: import auto /pub/geog4103/contour3 contour3
Task: Unit conversion
Your contour lines have an elevation attribute in feet. You will need to
change them to meters using Info. In Info, use the calculate command to
convert the units to meters [i.e. elevation = elevation * 12 / 39.37]
Arc: info
ENTER USER NAME>ARC
ENTER COMMAND >SEL CONTOUR3.PAT
ENTER COMMAND >CALC ELEVATION = ELEVATION * 12 / 39.37
ENTER COMMAND >Q STOP
Task: Convert the arc coverage of contour lines to a TIN coverage
In the example below, the input coverage is contour, the TIN output
coverage is contin, and the attribute in the contour coverage that
represents elevation is "dxf-elevation" (if from AutoCAD files) or
"elevation" (if from Arc files). The arctin command uses the term
spot-item to refer to the elevation for each feature in the input
coverage.
Arc: arctin contour3 contin3 LINE elevation
Task: Convert TIN to a Lattice
Arc: tinlattice contin3 conlat3 LINEAR
[Note: Notice the extreems of the data are displayed]
Xmin = 200.000 Ymin = 1.730
Xmax = 400.000 Ymax = 200.000
X-extent = 200.000 Y-extent = 198.270
Enter lattice origin : 200 0
Enter lattice upper-right corner : 400 200
Enter lattice resolution : 21
The lattice you have created is in the form suitable for the GRID module.
Task: Displaying the TIN and Lattice
Arc: ap
Arcplot: &term 9999
Arcplot: disp 9999
Arcplot: mape contin3
Arcplot: tin contin3 {display the tin edges}
Arcplot: linecolor 3
Arcplot: arcs contour3 {examine the tin for flat triangles}
Arcplot: latticemarkers conlat3 4
Arcplot: gridshades conlat3 {random colors}
Arcplot: shadeset colorrange.shd {set the color range}
Arcplot: shadecolorramp 1 256 blue red {256 colors red-blue}
Arcplot: gridshades conlat3 # linear nowrap {red-blue linear}
TASK 3. Compute the surface angles for the Grid
Task: Comppute the slope angles and statistics
Arc: grid
Grid: slope_gr = slope(conlat3,percentrise) {% slope}
Grid: describe slope_gr
Grid: slodeg_gr = slope(conlat3) {slope in degrees}
Grid: describe slodeg_gr
Grid: aspdeg_gr = aspect(conlat3) {aspect in degrees}
Task: Display the Grid files you have created
Grid: ap mape conlat3
Grid: ap gridpaint conlat3
Grid: ap gridpaint conlat3 # linear # gray
Grid: ap gridpaint slodeg_gr # linear # gray
TASK 4. Create a Copy of the East Portal DEM Coverage Converting from ERDAS
Arc: imagegrid /pub/geog4103/dem/epor_dem.gis epor_dem
Arc: grid
Task: Display the elevation surface first
Grid: ap mape epor_dem
Grid: ap gridpaint epor_dem
Grid: gridpaint epor_dem # linear # gray
Grid: shaded2 = hillshade(epor_dem,315,35,#) {sun NW at 35 deg}
Grid: shaded3 = hillshade(epor_dem,135,35,#) {sun SE at 35 deg}
Grid: ap gridpaint shaded3 # linear # gray
Grid: ap gridpaint shaded2 # linear # gray
Task: Determine some statistical characteristics of the study area
You can use the describe command to find the minimum, maximum, average,
and standard deviation of the values in an elevation grid, slope grid,
aspect grin, etc.
Grid: describe epor_dem
TASK 5. Clean-up the Files You Created
Arc: kill slope_gr all
Arc: kill slodeg_gr all
Arc: kill aspdeg_gr all
Arc: kill shaded2 all
Arc: kill shaded3 all
TASK 6. Compute the slope and aspect statistics for the East Portal DEM and
fill in the "Turn In" sheet.
TASK 7. Now go back and digitize the contour map you have been provided,
construct a lattice, slope and aspect grids, and then compute the necessary
statistics. Use the following minimum, maximum and cellsize values.
Arc: tinlattice contin conlat LINEAR
Enter lattice origin : 263480 4185200
Enter lattice upper-right corner : 267980 4188400
Enter lattice resolution : 151
TURN IN
What are the following statistics for the study areas?
CONLAT area EPOR DEM
Minimum Elevation _______feet _______m
Maximum Elevation _______feet _______m
Average Elevation _______feet _______m
Minimum Slope ___% ___deg ___% ___deg
Maximum Slope ___% ___deg ___% ___deg
Average Slope ___% ___deg ___% ___deg
----=----=----=----=----
*** From Intro to GIS (Hodgson/Kelly) Lab #11
Refine East Portal DEM
Grid: list epor_dem.vat {Note 0 values. Recode 0 to NODATA}
Grid: epor2_dem = select(epor_dem,'value > 0')
Grid: slope_gr = slope(epor2_dem)
Subset EP DEM to match study
Grid: setwindow 440025 4414005 445995 4417995
Grid: status
Grid: myep_dem = epor2_dem
Grid: describe myep_dem
Import Maggi's Hydro and Watershed Data
Arc: import auto /pub/geog4103/wshed.e00 mywshed
Arc: import auto /pub/geog4103/hydro.e00 myhydro
Create/display DEM shaded relief
Grid: shaded = hillshade(myep_dem,315,55,#)
Arcplot: &term 9999
Arcplot: disp 9999
Arcplot: mape myep_dem
Arcplot: gridpaint shaded # linear # gray
Arcplot: linecolor 3
Arcplot: arcs mywshed
Arcplot: polygonshades myhydro 4
Rastorize vector data
Grid: setwindow myep_dem
Grid: myhyd_line = linegrid(myhydro,#,#,#,30,nodata)
Display
Arcplot: gridpaint myhyd_line
...random colored lines undesireable...
Grid: describe myhyd_line
Grid: myhyd2_line = con(myhyd_line > 0,1,0) {all 0 or 1}
Rastorize polygon in hydro and water covers using "-id" to assign
Grid: setwindow myep_dem
Grid: myhyd_pol = polygrid(myhydro,myhydro-id,#,#,30)
Grid: mywshed_pol = polygrid(mywshed,mywshed-id,#,#,30)
Display
Grid: gridpaint myhyd_pol
Grid: gridpaint mywshed_pol
List the Value Attribute Tables of each cover
Grid: list myhyd_line.vat
Grid: list myhyd_pol.vat
Grid: list mywshed_pol.vat
...area of feature = count (# cells) x cell size (30m x 30m)...
Determine statistics in the study area
Range of elevation values for each watershed
Grid: tab_wshr = zonalstats(mywshed_pol,myep_dem,range)
Grid: list tab_wshr
Average elevation of each watershed
Grid: tab_wsh = zonalstats(mywshed_pol,myep_dem)
Grid: list tab_wsh
Min, max, and average elevation of each lake
Grid: describe myep_dem
Range of elevation values for each lake
Grid: tab_hydr = zonalstats(myhyd_pol,myep_dem,range)
Grid: list tab_hydr
Average elevation of each lake
Grid: tab_hyd = zonalstats(myhyd_pol,myep_dem)
Grid: list tab_hyd
Highest lake?
*** From Intro to GIS (Hodgson/Kelly) Lab #12
Arc: import auto /pub/geog4103/st_25m.e00 st_25m
Arc: import auto /pub/geog4103/cities.e00 cities
Find out projection parameters
Arc: describe st_25m
Arc: describe cities
Generate stations cover
Arc: generate stations
Generate: input /pub/geog4103/stations.dat
Generate: points
Generate: q
Arc: build stations points
Create an Info File of the Precip Data
ENTER COMMAND >DEFINE PRECIP.INF
ITEM NAME>STATIONS-ID,4,5,B
ITEM NAME>PRECIPITATION,4,8,F,2
ITEM NAME>
ENTER COMMAND >ADD FROM /PUB/GEOG4103/PRECIP.DAT
ENTER COMMAND >Q STOP
Arc: joinitem stations.pat precip.inf stations.pat stations-id
stations-id
Arc: projectdefine cover stations
Project: projection geographic
Project: units dd
Project: parameters
Project the city loc into the Albers proj (everythingelse is)
Arc: project cover stations stations_a
Project: output
Project: projection albers
Project: units meters
Project: parameters
1st standard parallel [ 0 0 0.000 ]: 29 30 0
2nd standard parallel [ 0 0 0.000 ]: 45 30 0
central meridian [ 0 0 0.000 ]: -96 0 0
latitude of projection's origin [ 0 0 0.000 ]: 23 0 0
false easting (meters) [ 0.00000 ]:
false northing (meters) [ 0.00000 ]:
Project: end
Vector to Rastor conversion of covers
Grid: setwindow -2360000 260000 2260000 3180000
Grid: states_pol = polygrid(st_25m,state_fips,#,#,20000)
Grid: mape states_pol
Grid: gridpaint states_pol
Create an annual precip for same study area as lower 48 states
Grid: usage idw
Grid: precip_sur = idw(stations_a,precipitation,#,2,SAMPLE,6,#,20000)
Grid: gridpaint precip_sur # linear # gray
Using Grid "if" create grid with 1 = inside 48 states and 0 = outside
Grid: usage if
Grid: if (states_pol >= 1)
:: inus_pol = 1
:: else inus_pol = 0
:: endif
Grid: gridpaint inus_pol
Grid: precip_sur_in = precip_sur * inus_pol
Grid: gridpaint precip_sur_in # linear # gray
Create grid of US cities with unique IDs
Grid: setwindow states_pol
Grid: cities_poi = pointgrid(cities,cities-id,#,#,20000,nodata)
Create grid of only Mobile, AL (fungus source)
ENTER COMMAND >SEL CITIES.PAT
ENTER COMMAND >RES NAME EQ 'Mobile'
ENTER COMMAND >LI
Grid: if (cities_poi == 22349)
:: mobile_poi = 1
:: endif
Create surface showing Euclidean distances from Mobile, AL
Grid: usage eucdistance
Grid: dist_mob = eucdistance(mobile_poi,#,#,5500000,#)
Grid: mape dist_mob
Grid: gridpaint dist_mob # linear # gray
Grid: dist_us_mob = dist_mob * inus_pol
Grid: gridpaint dist_us_mob # linear # gray
Distance
Grid: city_mob = zonalstats(cities_poi,dist_mob,min)
Modify info file to 1)join with cities and 2)display entire distance value
ENTER COMMAND >SEL CITIES.PAT
ENTER COMMAND >IT
ENTER COMMAND >SEL CITY_MOB
ENTER COMMAND >LI
ENTER COMMAND >ALTER
ITEM NAME>VALUE
ITEM NAME>CITIES-ID
ITEM OUTPUT WIDTH>5
ITEM TYPE>B
ITEM PROT. LEVEL>
ALTERNATE ITEM NAME >
ENTER KEY LEVEL>
ENTER INDEX NUMBER>
ENTER COMMAND >ALTER MIN DISTANCE 15 F 0 (cr)x4
ENTER COMMAND >LI
Arc: joinitem city_mob cities.pat dist_city.inf cities-id cities-id
Arc: items dist_city.inf
Arc: list dist_city.inf
Create frictional surface
Grid: precip_fric = (2500 - precip_sur_in) * .000001
Create min precip barrier
Grid: if (precip_sur_in > 1000)
:: precip_fric2 = precip_fric
:: endif
Compute time from Mobile
Grid: days = costdistance(mobile_poi,precip_fric2,#,#,999999,#)
Need zonalstats, cities_poi for distances to cities, modify and join info again
(
geocities.com/hanson_c)