arcview gis - university of torontoprod.library.utoronto.ca/maplib/arcview_gis.pdf · arcview is...

Map Library ArcView � Version 1 � 02/20/03 of 12

ArcView GIS

1. Introduction1

ArcView is the most popular desktop GIS analysis and map presentation software package.. With ArcView GIS you can

create intelligent, dynamic maps using data from numerous sources. ArcView GIS includes tools and data you can use out-of-

the-box to perform state-of-the-art analysis on key issues. It is also one of the easiest GIS software solutions to learn and use.

2. Starting ArcView

When you start ArcView you will see the main ArcView application window containing a menu, button bar and a

subwindow named untitled (Figure 1).

This subwindow allows you to either create a new project (as an existing view or a new blank project) or to open an

existing project. A project is a file in which you store the work you do with ArcView. A project contains all the views, tables,

charts, layouts and scripts that you use for a particular ArcView application. In this way, work is stored together in one

convenient place. Project files have an .apr extension.

1 From Arcview 3.X brochure [http://www.esri.com/library/whitepapers/av_lit.html#ArcView 3.x Brochure].

Figure 1. Opening ArcView presents a subwindow named untitled.


3. Opening a project

In the dialogue box that appears (Figure 2), navigate the directory of the folder where the ArcView project to be used has

been saved. In this example, we use the project ‘qstart.apr’ that is located in the ‘C:\esri\av_gis30\avtutor\arcview’ directory.

Select the project called ‘qstart.apr’ and press ‘OK’.

When the project opens, you will see a window called ‘qstart.apr’. This is the Project window (Figure 3). The

project window gives you access to all the components contained in the project file. It also enables you to create new

components. The project qstart.apr contains three views. A view is an interactive map that lets you display, explore, query,

and analyze geographic data in ArcView.

Figure 2.Opening an existing ArcView project.

Figure 3. The three views contained in qstart.apr.


4. Views

Each of the three views in qstart.apr can be opened by selecting the name of the view then pressing ‘Open’. Multiple

views can also be opened at the same time by selecting two or more views before pressing ‘OK’ (Figure 4). The three views

opened in Figure 4 show (a) a world map (displaying projected population for 2000), (b) a map of the USA and Canada

(displaying States and Provinces), and (c) a map of Atlanta (displaying streets, highways and census tracts).

A view is made up of layers of geographic information for a particular area or place. Each layer is a collection of

geographic features, such as rivers, lakes or countries. In ArcView, these layers are called themes. All the themes in a view

are listed to the left of the map in the view’s Table of Contents. The table of contents also shows the symbols used to draw

the features in each theme. The check box next to each theme indicated whether it is currently drawn on the map or not. The

order in which the themes are listed in the Table of Contents is also important. The themes at the top of the Table of Contents

are drawn on top of those below it. Themes that form the background for a map (e.g. ocean) are thus listed at the bottom of

the Table of Contents.

Figure 4. Multiple views opened in project qstart.apr


5. View Controls

The ArcView interface has four main control areas, which change to accommodate the active document type. These

are (Figure 5):

� Main menu bar. This controls nearly everything. Keyboard shortcuts for some menu items are listed on the menu.

� Upper button bar. This is a convenient shortcut to many of the menu functions. If you place the mouse pointer over

one of the buttons, a tool tip will appear that provides help on the icon’s purpose.

� Lower tool bar. This allows you to select the function of the pointer or mouse cursor. The pointer is used for many

purposes, but performs only one at a time, depending on the tool bar setting. Tool tips also appear on all tool items.

� Status bar. This is located at the bottom of the ArcView window and provides visual feedback on the current mouse

action and updates on the status of a process, among other things.

When a view is the active document, the menu, button and tool bars perform actions on the view or its individual

themes. The controls on the button bar immediately affect the view, while the tool bar changes the pointer function. The

pointer function remains the same until a new tool is chosen.

The scale at which your view is displayed is shown on the lower tool bar. It is possible to change the scale at which

the view is displayed using a variety of tools. One way to change the scale of the view is to specify a scale directly. To do

this, click inside the Scale field in the lower tool bar, then type in your desired scale. Once you have entered the new scale,

press ENTER on your keyboard. The view will redraw at the scale

you specified, centered on the middle of the view. If the scale of

your view is currently blank, you first need to tell ArcView what

coordinate units the data in your view is stored in before you can

type in a scale. To do this, go to the View menu in the upper tool

bar, and select properties. A dialogue box will appear. In this box,

choose the appropriate units from the Map Units drop-down menu

(Figure 6).

Figure 5. Toolbars in ArcView interface

Figure 6. Dialogue box in which coordinate unitsare specified.


In addition to changing the scale of the view manually, scale can also be set automatically as one navigates within a

view. The most common ways through which one is able to zoom in and out of a view (and hence, change the scale of the

view) are listed below in Table 1.

Button Tool/Button Name Function

Zoom in

To zoom in centered on a particular position on theview, click that position once with this tool. To zoom in

on a particular area, drag a box over the area (bydepressing the left mouse button) with this tool.

Zoom out Same as above, but this tool zooms out from the positionyou click or drag over.

ToolWhen you select a tool and move

the cursor over the view, thecursor changes shape to reflectthe tool you selected. This tool

remains selected until youchoose a different one.

Pan

Lets you pan by dragging the display in any directionwith the mouse. To pan, click this tool, move the cursoranywhere over the view, hold down the mouse button,and drag in any direction. Release the mouse button to

leave the view in your desired position.

Zoom tofull extent

Zooms to the full spatial extent of all the themes in yourview.

Zoom toactivetheme

Zooms to the spatial extent of the active theme(s) inyour view. Because themes on a map often cover

different spatial extents, this button easily allows you tozoom in on an area covered by a particular theme ofinterest. Before clicking this button, make sure the

theme that you want to zoom to has been chosen fromthe view’s Table of Contents. This will make this theme

active. Multiple themes can be made active bydepressing the SHIFT button on the keyboard while

electing themes.

Zoom toselectedfeatures

Zooms to the spatial extent of the currently selectedfeatures in the active themes.

Zoom incenter Zooms in once on the center of the view.

Zoom outcenter Zooms out once on the center of the view.

ButtonWhen you select a button, it willperform a specific procedure. Torepeat the procedure, select the

button again.

Zoom toprevious

extent

Goes back to the previous spatial extent you wereviewing.

Table 1. Tools and Buttons for navigating within a view and changing view scale automatically.


6. Creating a new map in ArcView

Often you will not want to open an existing project after starting the ArcView program, but instead want to create a new

project. To do this, run ArcView, then choose the create new project (with a new view) option from the dialogue box that

opens up (see Figure 1). This will then open up a new ArcView project which is ‘empty’ (i.e. contains no data) (Figure 7).

To add spatial data to the project, click the add theme button . In the dialogue box that appears, navigate to the

directory in which your spatial data files are saved. Select the data source type of the files that you want to open

(Feature, Image, Grid and TIN data sources). All the spatial data files corresponding to this data type will then appear in

a list in the left-hand window of the dialogue box. Select the file(s) that you wish to open, and click OK.

Figure 7. A new ArcView project.

Figure 8. Adding a theme to the blank project.


7. Feature, Image, Grid and TIN Data Source Types

� Feature data source type

� ArcView shapefiles: The dialogue box opened by selecting the add theme button (Figure 8) uses the Feature data

source type as its default. This data source corresponds to files that are saved according to the ArcView shapefile

format (.shp extension2) and ARC/INFO coverages. Shapefiles are ArcView’s native spatial data format. Shapefiles

store location and attribute data for geographic data. They are not as robust as ARC/INFO coverages in terms of

topology, but they have key advantages in ArcView. Shapefiles draw more rapidly in a view, and ArcView can edit

both the geographic and attribute data of a shapefile. In addition, ArcView can create new data in the shapefile

format.

� ARC/INFO coverages: ESRI’s ARC/INFO is a GIS program used for handling, managing and analyzing geographic

information. As a result, the ARC/INFO coverage format is the most popular and widely available spatial data

format used in digital mapping and GIS applications. With ArcView you can access almost any spatial data stored in

ARC/INFO format. You add an ARC/INFO coverage to a view in the same way you add a shapefile, by clicking the

add theme button. In Figure 9, the working directory contains shapefiles (identified by their .shp extension) and

ARC/INFO coverages (identified by no extension).

Sometimes an ARC/INFO coverage will contain more than one class of geographic features. For example, a

coverage containing polygon features, such as land parcels, may also contain arc (i.e. line) features which store

information about the boundaries between parcels. When you add an ARC/INFO coverage containing more than one

feature class to a view, you must choose the feature class that you want to represent. This is because a theme can

only represent one class of features from a coverage. However, you can add several themes to a view each based on

a different class of features from the same ARC/INFO coverage. Coverages that contain more than one feature class

are shown with yellow folders next to them in the Add Theme dialogue box (Figure 10).

2 Shapefiles are actually three files (sometimes more), each with their own extension. Shape (.shp) files store each geographic feature in its own record as alist of x,y coordinate pairs. The shape index file (.shx) contains one fixed-length record for each record in the .shp file. The .shx files can be ready quicklyand so serve as a lookup table for the records in the .shp file. The dBase file (.dbf) stores attribute information for features in the .shp file. The .dbf filecontains one record for each feature in the .shp file. Other files often associated with shapefiles include spatial indexes (.sbn; .sbx) and attribute indexes(.ain; .aih). When copying a shapefile from one directory to another it is thus important to ensure that all associated files have been copied!!!

Figure 9. A working directorycontaining shapefiles (.shp) andARC/INFO coverages (no fileextenstion).


You can click on the yellow folder icon next to this coverage to see what feature classes it contains (Figure 11). In

this example, the coverage called municipal contains four feature classes: Polygons, arcs and labelpoints (points

inside polygons that have the same tabular attributes as the polygons).

You can then choose the feature class that you want to add. If you select a coverage such as electoral in this

example, without selecting a particular one of its features, ArcView uses the first feature class listed (in this case,

polygons) as the default class for the new theme. Figure 12 shows what your newly created view may look like after

various feature classes (in this case polygons and arcs (lines)) have been imported into ArcView.

Figure 12. Examples of Feature(shapefile; ARC/INFO coverage) datasource types.

Figure 10. A working directorycontaining an ARC/INFOcoverage that contains more thanone feature class.

Figure 11. The threedifferent feature classes ofthe coverage electoral.


� Image data source type (Figure 13): An image is a type of spatial data based on rows and columns, where a single piece

of information is stored in each pixel (or grid-cell). This data structure is also often referred to as a raster structure. In

satellite data, for example, each pixel contains a value for the light energy reflected back from a portion of the earth’s

surface. Some images contain more than one band of data, where a band represents a specific range in the

electromagnetic spectrum. ArcView supports both single and multiple band images. Black and white, grayscale and

pseudocolor images are displayed as single band images. True color images are displayed as multi-band images.

ArcView supports a number of image formats, including band-interleaved (.BSQ, .BIP, .BIL); ERDAS LAN and GIS;

ERDAS IMAGINE; JPEG; BMP; TIFF and GeoTIFF, as well as others).

� Grid data source type: The grid data structure is similar to that described above for images. Grids are often used to

represent geographical phenomena that vary continuously over space, such as terrain. To add a grid as a grid theme and

work with the data it contains, use ArcView’s optional spatial analyst extension, which is available separately from

ESRI. If you don’t have the spatial analyst extension, you can add a grid to a view as a single band image (see above).

� TIN data source type: A TIN data structure allows for the efficient generation of surface models for the analysis and

display of terrain and other types of surfaces. Since representation of a surface can be done in many different ways, TIN

(Triangulated Irregular Network) also implies a specific storage structure of surface data. TIN partitions a surface into a

set of contiguous, non-overlapping, triangles. A height value is recorded for each triangle node. Heights between nodes

can be interpolated thus allowing for the definition of a continuous surface. TINs can accommodate irregularly

distributed as well as selective data sets. This makes it possible to represent a complex and irregular surface with a small

data set.

Figure 13. An example of an Image data sourcetype.


8. Other data you can add to views in ArcView

In addition to the four data types listed in the previous section, ArcView is able to directly import various other data

types, including:

� Computer Aided Design (CAD) drawings: To add CAD drawings to a view, you can use the CAD reader extension that

comes with ArcView.

� Tabular data: ArcView also supports tabular data in dBASE, delimited text, and INFO format (INFO is the database

format used in ARC/INFO for tabular data). Using ArcView’s SQL connection feature, you can also connect to a databse

server, such as Oracle of Sybase, and run an SQL query to retrieve tabular data from it.

� Mapinfo interchange (MIF) format: ArcView’s MIF to shape utility lets you convert data in MIF format into shapefiles.

9. Adding tabular data to maps

An easy way to get data into ArcView is to type it directly into the attribute table belonging to a theme that you are

interested in. Suppose someone has given you a piece of paper with the latest sales figures for Andrew Davidson replica

Bandits Hockey Sweaters for each Province in Canada and you want to add them to your map so you can display the

Provinces with different colours according to sales. Imagine you have also created a theme for Canada’s Provinces (here we

use the canada.shp file. Here is how you add a new field to this theme’s attribute table and type into your data so it can

symbolize the Provinces based on these values:

(a) In the table of contents, click on the name of the theme that you want to add data to, to make it active.

(b) Click the Open Theme Table button . The theme’s attribute table appears (Figure 14). In this example, there is

one record for each Province in Canada.

Figure 14. Canadian Provinces shapefileand its theme attribute table.


(c) Choose Start Editing from the Table menu. Choose Add Field from the Edit menu. In the Field Definition dialogue

box, type a name for the new field that you want to create then press OK.

(d) Click the edit tool , click on the first cell in the new field, and type in the first value. To move to the next cell,

click on it (or press RETURN). Fill out all the value for the new field.

(e) Once you have finished entering the values, choose Stop Editing from the Table menu. You’ll be prompted to save

your changes (choose yes).

(f) Now that you have added your data to the theme’s attribute table, you can symbolize the features in the theme based

on these values. Click on the view to make it active then double-click on the theme in the view’s table of contents to

display ArcView’s legend editor. The legend editor lets you specify how a theme is displayed. In the legend type

Figure 16. Entering data into the newlydefined field.

Figure 15. Defining a new fieldin the Canadian Provincesshapefile.


list, choose graduated color. In the classification field list choose the name of the field that you just added to this

theme’s table (in this example, Davidson_sales). ArcView will automatically classify the features in the theme

according to the values in the field and choose colours for each of the classes (Figure 17).

(g) If desired, you can choose a different colour scheme by selecting from the Color Ramps list, or change any of the

colours by double-clicking it to display the Colour Palette. Press apply on the legend editor to draw the theme using

this classification (Figure 18).

(h) Now that you have added your data to the theme’s attribute table, using it to symbolize the map’s features is just one

of the ways you can work with it. For example, you can label the theme’s features with your data values, create

charts to complement your map, and perform queries to solve problems or find things out, such as finding features

on the map that have certain data values.

Figure 17. Specifying coloursfor displaying the new theme.

Figure 18. Classification ofProvincial sales of AndrewDavidson replica hockey sweaters.

arcview gis - university of torontoprod.library.utoronto.ca/maplib/arcview_gis.pdf · arcview is...

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