GIS

Class

features based on a quantity attribute based on the values for that attribute and represents a range in values

common methods for symbolizing classes

graduated colors and graduated symbols

Feature Symbol

has a shape, outline, color, pattern, or all of these (simple or complex)

Lines of lattitude run

in horizontal bands n/s of equator at 0deg to 90 +/-

Lines of longitude run

in vertical bands e/w of GM at 0 deg to 180+/-

Feature Attributes

information that describes the feature (i.e. country - name, population, capital)

Features in a layer

use the same shape, and have the same type of attributes which represent the same theme (i.e. roads, lakes, mountain peaks) of a real world object

GIS (Shellito)

Computer based mapping, analysis, and retrieval of location based data.

Natural Breaks (Jenks)

classification scheme good for most data

Precision

# of decimals, fine a measurement

Geographic Approach (def.)

1. Collect and organize geographic data to understand E 2. Analyze data to create geographic knowledge 3. Apply geographic knowledge to find solutions (a way to gain understanding and solve problems by creating and applying geographic knowledge with GIS as a tool)

Transformation, uses displacement link and

ALWAYS BEGINS ON THE BUILDING AND ENDS ON PHOTO

GIS (defined)

An integrated computer system that is used to display, store, manage, and analyze data about objects on the earth.

5 Steps in the Geographic Inquiry Process

Ask, Aquire, Explore, Analyze, Act

Uses of the geographic approach

Automate workflows Use resources wisely Organize key information Make and support decisions

GCS measurements are made in

DMS or DD

Attributes

Describe features in a GIS (Name of a country, its population, and area)

Types of information stored in a GIS

Features and Attributes

When Mapping Quantities

Features are grouped into classes that represent a range in values

Geospatial technology encompasses (Shellito)

GIS, remote sensing, and GPS

GIS (Acronym)

Geographic Information System (pictures in the form of a map which are created by a computer system containing a database, a graphics program and tools to manage, edit and analyze geographically located data called features and attributes)

How is geographic data stored?

In a database called a Geodatabase and organized into feature classes

How are features organized in a geodatabase?

In feature classes

Feature Location (expressed as)

Latittude and Longitude

Thematic map attribute values

can be category or quantity in nature

Thematic Map

Map on which features are symbolized based on an attribute which conveys more information

Three common unprojected datums

NAD 27, NAD 83, WGS 84

Features

Natural objects and human defined objects (all real world objects, trees, buildings, roads, rivers, continents, oceans, counties, census tracts, parcels)

Differences between Paper, Digital, and GIS maps

Paper - static, image does not change like a photograph Digital - map viewed on a computer which may be static like a paper map or may have some dynamic tools for finding a location, zooming, panning. GIS - more than a map, has a database behind it with tools to bring more information in, display data in various ways, look at sets of data to see patterns & compare relationships, analyze data to create new information, and helps to provide answers to questions.

Shapes of a Feature

Point, Line, Polygon

Components of a Feature

Shape Location Symbol Attributes

To preform a location query what must you specify?

The layer that contains the features you want to select The location relationship you want to analyze The layer that contains related features

Functions of a GIS

Visualization, Geodata Management, and Analysis (3 primary functions)

Geography (Shellito)

Where things are, and why things are where they are

Three types of geographic questions:

Where, Why, What If

Layer

a collection of features, a visual representation of a feature class on a GIS map

a feature class is

a digital dataset of features stored in a table with the same shape and set of attributes

What is a query?

a question about features

Analysis

applying GIS tools to geographic data to answer questions and support decisions.

A degree of latitude is

approximately 69 miles, and a minute of latitude is approximately 1.15 miles. A second of latitude is approximately 0.02 miles, or just over 100 feet.

What are the two types of query's?

attribute and location

A Map Layout

is a map product that will be shared with others, may be designed for print or digital viewing, and should always include at least these four elements - map body, legend, scale indicator, and title.

output of a buffer operation

is a new polygon dataset

a buffer

is a zone of specified distance around a feature

A degree of latitude

is approximately 69 miles, and a minute of latitude is approximately 1.15 miles. A second of latitude is approximately 0.02 miles, or just over 100 feet.

Geospatial Data (Shellito)

is at the heart of geospatial technology applications

ArcMap

is the ArcGIS application used to display and work with GIS maps

a classification scheme

is the method used to create classes. There are many types ie Natural Breaks (Jenks) and determine how the class ranges are created.

Visualization

looking at data on a map to get information and see relationships (GIS Map is a window into your data with different views to see relationships and patterns)

Lines of Longitude are also known as

meridians

Accuracy

more correct=reality

Thematic map category values can be

names, types, or conditions of features and use different symbols based on the feature (ex city circle, capital star..)

What are the four main types of location query?

near (within a distance of) adjacent to intersect inside

Thematic map quantity values are

numbers representing amount, percentages, or ranks and are grouped by feature and each is assigned a symbol which may show progression of color or size in a series (ex color going from white to dark red for population age)and are called a class

a feature class table has

one record (row) for every feature and one column for every attribute

Geodata Management

organizing and updating information so that it is useful

Lattitude lines are also known as

parallels

Vector Primitives

point, line, and polygon

compound query

query expressions that use an operator called a "connector" to find multiple attribute criteria

Scale

size of a feature on a map in relation to that objects size in the real world, represents reduction in size expressed as a ratio or equivalence and is dynamic in GIS to see more or less detail

buffers can be used

to determine what is happening inside them or can be combined with other data to create new data

Raster Data

used for continous data, stored in equally sized cells arranged in rows and columns which contain values or codes, coordinates of the raster's origin are what link it to a real world location

Vector Data

uses shapes to represent features and is useful in representing features with distinct boundaries and is defined by coordinates and link them to real world location

The two common data storage methods are

vector and raster

When do you use a location query?

when you are looking for features whose locations meet certain criteria

When do you use an attribute query?

when you are looking for features with specific attributes

To preform an attribute query

you create a query expression which includes: attribute field, operator, attribute value