MIDTERM key terms

Question 1

What is a map?

Answer 1

Maps describe spatial relationships. They are they way we index the landscape, represent and interpret spatial relationships, define places and spaces.

They also act as an assertion of power, and administrative control, explain social, cultural, and environmental processes

Question 2

What are maps composed of?

Answer 2

Map body, inset/overview map, titles, legend, scale, orientations/direction indicator, map metadata

Question 3

What is GIS?

Answer 3

GIS = Geographic informational systems
They embody the process of layering information and are a computerized system for capturing, storing, importing, analyzing, and managing data to be spatially references
LINKING LOCATIONS WITH INFORMATIONS

Question 4

What are GIS composed of?

Answer 4

hardware, software, data, people. Methods, internet

Question 5

What is the structure of a GIS?

Answer 5

(1) data layer (stores), (2) business layer (manages), (3) display and service layer (synthesizes)

Question 6

What are the elements that compose a map

Answer 6

Locations and attributes
Locations → positions in two dimensional spaces
Attributes → two types: identity and descriptions (e.g. qualities of quantities ex: city names or population figures)

Question 7

What is scale?

Answer 7

scale is a ratio of map unions to earth units - with the mpa units standardized to 1. The area is unitless measure. Meaning the scale is consistent regardless of unit of measurement (e.g miles, km, feet, meters

Question 8

how do you calculate scale?

Answer 8

Scale = map distance/earth distance

Question 9

What is geospatial data?

Answer 9

there are 2 types of geospatial data: vector and raster

Question 10

Describe Vector data

Answer 10

Vector → is a representation of the world using points, lines, & polygons. It is a method of storing, representing or displaying spatial data in digital form. It consists of using coordinate pairs (x,y) to represent locations on the earth.

Question 11

describe raster data

Answer 11

Raster→ images are composed on individual pixels and each square in a image is one pixel

Question 12

Describe a data layer

Answer 12

vector and raster data are used to compose differnt data layers which are grouped by theme. There is only one themse per layer

Question 13

What is a feature?

Answer 13

Features are the identifier of each geographic object that composes a layer. Features are linked to rows in the attributes table and can take the form of points lines or polygons. Features have attributes that identify and describe features

Question 14

What are the basic types of mapping

Answer 14

general reference mapping, special purposes mapping, and thematic mapping

Question 15

How do we present geographic information on a map

Answer 15

Visual hierarchy → the order in which map element are perceived
Balance → map body vs white space
Contrast & use of color → emphasize or deemphasize certain map features on color selection

Question 16

Describe thematic mapping

Answer 16

A thematic map shows the spatial distribution of one or more specific data themes for standard geographic areas. They can portray physical, social, political, cultural, economic, sociological, agricultural, or any other aspects of a city, state, region, nation or continent

Question 17

What are the thematic mapping techniques?

Answer 17

Four thematic mapping techniques:
chloropleth (shaped by unit)
proportional symbol (graph/chart)
isarithmic (lines of equal value)
dot mapping (dots for values)

Question 18

How do we classify data for thematic mapping

Answer 18

Equal intervals → divisions at regularly spaced intervals
Quantiles → equal number of observations in each class
Natural breaks → classes formed around natural groups of data
Mean standard deviations → considers the mean (average) of the data and calculates how the data deviates from the mean
Manual → DIY classes/make your own
Geometrical interval → minimized the sum of square of the number of elements in each class

Question 19

What is a geographic coordinate system?

Answer 19

Geo coordinate system → global or spherical coordinate systems such as longitude and latitude
Also known as graticule → latitude (parallels) and longitude (meridian)

Question 20

What are the types of approximations of earth using spatial data

Answer 20

sphere, ellipsoid, or geoid

Question 21

What composes a coordinate system?

Answer 21

includes an angular unit of measure, prime meridians, and a datum
Datum → center of the sphere/defined the positions of the spheroid relative to the center of the earth

Question 22

What are map projections?

Answer 22

→ coordinate systems that provide various methods of projecting the earth’s spherical surface into a two dimensional cartesian (long and lat) coordinate plane

Question 23

define a developable surface

Answer 23

→ a mathematical definable surface onto which the land masses and graticule are projected from the reference globe

Question 24

what are the characteristics of all map projections?

Answer 24

Case → related to how the developable surface positions with respect to the reference globe - how it touched the globe

Aspect → the viewing angle deals with the placement of the projections center with respect to the earth’s surface. We can view the earth in three aspects (equatorial, polar, and oblique)

Class → refer to the overall appearance of the graticule once the projections process of complete (this is the cylindrical, conic, and planar classes)

Question 25

What are standard lines?

Answer 25

Standard lines → indicate the point(s) which the developable surface touches the reference globe
The globe can touch via tangent lines (once) or secant lines (twice)

where these lines touch are where there is the least distortion, the farthest places from these points result in the most distortion

Question 26

What are the 4 spatial relationships that can be preserved or distorted by map projections

Answer 26

Relationships:
Area, angle (shape), distance, directions

Projections (that can save the relationships):
Equivalent or equal area, conformal, equidistance, azimuthal projections

Question 27

What is a grid system?

Answer 27

→ a grid is placed over a map projections eyeing a plant or cartesian (x,y) coordinate system to locate features

Question 28

What are the types of grid systems

Answer 28

Universal transverse mercator (UTM)
State plane coordinate systems (SPCS)

Question 29

Define model

Answer 29

Model → Idealized and simplified representations of the world

Data model → is a set of constructs for representing object and process in the digital environment without reference to their locations

Spatial data model → a set of constructs for representing geographical objects, data, processes and relationships int e digital environment, for the purposes of analysis and complex problems solving

Question 30

What is a table?

Answer 30

Tables → are used to organize feature attributes. There is a one-to-one linkage between rows in the table and the spatial data the feature layer
Each feature in the data layer has only one entry in the table. Associated data is held in a relational database system (RDBMS)

Question 31

what is topology?

Answer 31

Topology→ a set of user defined roles and is the study of the mathematical relationship between points lines (arcs) and polygons. It enables the creation of continuous surface

Question 32

Define vector

Answer 32

Vector → is a representation of the world using points, lines, & polygons. a method of storing, representing or displaying spatial data in digital form. It consists of using coordinate pairs (x,y) to represent locations on the earth.

Question 33

define raster

Answer 33

Raster→ images are composed on individual pixels and each square in a image is one pixel. It consists of using cell data arranged in a regular grid pattern in which each unit (pixel or cell) with the grid is assigned an identifying value based on its characteristics. Each cell has an entry in the attribute table .

Question 34

What is the Procedural modeling process when faces with a problem?

Answer 34

Need to combine different layers of information.
Procedural for modeling process:
1. Identify the problem
2. Breakdown (simplify) the problem into smaller steps
3. Organize the data required to solve the problem
4. Develop a clear & logical flowchart using well defined operations
5. Run the model and modify (calibrate) it if necessary

Question 35

What is a feature

Answer 35

Each feature has attributes, a feature cna take the form of points lines and polygons and are linked to a row in the attribute table

Question 36

What are attributes

Answer 36

Attributes consist of a unique identifying key and descriptions.
Each row in the table is unique, columns represent attribute classes, rose represent individual records or observations

Question 37

What are database keys (any the types)?

Answer 37

Database keys → facilitate the relations in a relations database
Primary keys → unique identifier for EACH row of informations in a data file
Foreign keys → non unique identifier that carries information linked to the primary key. It is used to link formation in another table, and is often the primary key of another RDB

Question 38

What are structured Query language (SQL)?

Answer 38

SQL → standard computer language for accessing and managing databases

Question 39

define queries (and types)

Answer 39

Queries → are the primary method of data retrieval. Created new informations from existed info, both dont change the older/existing informations

Aspatial → queries using query algebra [ < > + <> ] => set algebra, [OR AND NOT] => boolean queries

Spatial → retrieving feature bases on their locations: can be done using adjacency or containment

Question 40

What are relates?

Answer 40

Relates →you relate two tables when the data in the tables have a one to many or many to many relationship

Question 41

What are joins?

Answer 41

Joins → you want to join tables when the data in the tables have a one to one or many to one relationships