Exam 3

Question 1

Vector data exploration

Answer 1

Input → Spatial operation → Output

Question 2

Spatial data allows us to

Answer 2

See/visualize

Question 3

Spatial Analysis

Answer 3

Use spatial operations to find relationships or patterns

Question 4

Vector data model

Answer 4

Points, lines, and polygons

Question 5

Exploration

Answer 5

Looking at data through stats, charts, and queries to understand patterns

Question 6

Spatial Query

Answer 6

Selecting features based on location or relationship

Question 7

Example of spatial query

Answer 7

Within 5 km

Question 8

Proximity / Adjacency

Answer 8

Determines which features are near or next to others

Question 9

Proximity can be seen as

Answer 9

Features based on location

Question 10

Adjacency can be seen as

Answer 10

All features that share a border (e.g. in state tuition)

Question 11

Containment

Answer 11

Determines whether one feature is inside another (select fea. in certain area)

Question 12

Containment example

Answer 12

All car crashes within a neighborhood

Question 13

Proximity / Adjacency example

Answer 13

All states that contain the Mississippi river

Question 14

Spatial Selection

Answer 14

Choosing features using spatial relationships (adjacency, containment)

Question 15

Dissolve

Answer 15

Merge features with a shared attribute to remove boundaries

Question 16

Buffer

Answer 16

Creates an area around a feature at a set distance

Question 17

Example of dissolve

Answer 17

Giving every state a number based on side of Miss. river, dissolving state lines so that it just shows E and W

Question 18

Example of buffer

Answer 18

Determine # of fast-food restaurants within 1 km of house

Question 19

Use a bigger buffer for

Answer 19

Bigger area or distance

Question 20

Overlay

Answer 20

Combines multiple layers into one, merging spatial and attribute data

Question 21

Example of overlay

Answer 21

Combining roads and wetlands

Question 22

Union (Overlay)

Answer 22

Keeps all features from both layers, overlapping or not

Question 23

Intersect (Overlay)

Answer 23

Keeps only features common to all input layers

Question 24

Clip (Overlay)

Answer 24

Cuts a layer using another layer as a boundary (“cookie cutter”)

Question 25

Raster Model

Answer 25

Represents continuous data (like elevation or temperature) using grid cells

Question 26

Vector vs Raster

Answer 26

- Vector = “Where is everything?” - Raster = “What is everywhere?”

Question 27

Resolution

Answer 27

Size of each cell; smaller cells = higher resolution.

Question 28

Orientation

Answer 28

Direction of grid alignment (usually north-south)

Question 29

Square Mesh

Answer 29

Raster cells form a square grid

Question 30

Cell Value

Answer 30

Numeric value stored for each cell, showing the attribute at that location

Question 31

Zone

Answer 31

Area made up of cells with the same value

Question 32

Class

Answer 32

Group of zones with related values

Question 33

Class example

Answer 33

All “forest” areas

Question 34

Area-class Layer

Answer 34

Layer where cells in the same zone have the same value

Question 35

Image Raster Layer

Answer 35

Layer with continuously changing pixel values (like photos)

Question 36

Mixed Pixel Problem

Answer 36

When one cell covers multiple features; what value to assign?

Question 37

Reclass / Recode

Answer 37

Changing cell values to simplify or group data

Question 38

Example of Reclass / Recode

Answer 38

Forest = 1, urban = 2

Question 39

Overlay (Raster)

Answer 39

Combines layers using math operations (+, −, *, /, min, max)

Question 40

Map Algebra

Answer 40

Using algebra-like functions to manipulate map layers

Question 41

Distancing (Raster)

Answer 41

Calculates distance to a set of target cells (like buffering)

Question 42

DEM (Digital Elevation Model)

Answer 42

Raster surface showing elevation values for each grid cell

Question 43

Generating DEMs

Answer 43

Created using photogrammetry, scanning, interpolation, or LiDAR

Question 44

Resolution (DEM)

Answer 44

Distance between elevation sample points

Question 45

Smaller pixel =

Answer 45

More detail

Question 46

Derivative Surface

Answer 46

Secondary surfaces created from DEMs (e.g., slope, aspect)

Question 47

Slope

Answer 47

Steepness or incline of the land

Question 48

Slope looks at

Answer 48

Each pixel around it to determine steepness

Question 49

Aspect

Answer 49

Direction a slope faces (north, south, etc.)

Question 50

What can aspect and slope be used for

Answer 50

Building houses

Question 51

Hydrologic Flow Modeling

Answer 51

Using DEMs to model water movement and drainage

Question 52

Drainage Basin / Watershed

Answer 52

Area of land that drains into a single water body

Question 53

Drainage Network

Answer 53

System of connected streams/rivers from DEM data

Question 54

Flow Direction (D4 vs D8)

Answer 54

Algorithms that determine how water flows across cells (4 or 8 directions).

Question 55

Vertical Profiling

Answer 55

Side-view cross-section of elevation across a line

Question 56

Viewshed Analysis

Answer 56

Determines what areas are visible from a specific point