Lecture 6

Question 1

Geoprocessing tools 5 categories:

Answer 1

overlay and proximity analysis
surface analysis
statistical analysis
table analysis
extraction analysis

Question 2

Overlay analysis

Answer 2

involves combining spatial and attribute data from two or more spatial data layers and examining their relationship

Question 3

top 6 tools on the geoprocessing menu

Answer 3

Buffer, Clip, Intersect, Union, Merge, Dissolve

Question 4

Surface analysis

Answer 4

tools that create layers of continuous data such as deriving a slope layer or an aspect layer from a Digital Elevation Model (DEM)

Question 5

Statistical analysis

Answer 5

examine both spatial and non-spatial statistical relationships.utilizing the basic geographic principal that object near each other are more likely to be similar then objects that are far apart

Question 6

Table analysis

Answer 6

finds answers based on table data

Question 7

Extraction analysis

Answer 7

tools which create smaller datasets from larger ones

Question 8

ERASE

Answer 8

Uses a binary input model and is the tool only accepts two layers: the input and the erased feature

Question 9

INTERSECT

Answer 9

uses a multiple input model, meaning the tool will find the areas common to all the layers

Question 10

MERGE

Answer 10

Merge will create one data set from two, with the output layer containing all the attributes from all of the input layers

Question 11

Difference between merge and append

Answer 11

one allows you to ‘smooth’ layers together/ creates a new feature class and the other ‘adds features’ to an existing layer/ provides a new feature class with similar fields

Question 12

Union

Answer 12

combines two or more data sets and compare the relationship between the two, adding fields to the attribute table and splitting geometric features to reflect this relationship. It retains all data from both the bounding and data layers.

Question 13

Clip

Answer 13

known as a “cookie cutter” overlay. Use this tool to cut out a piece of one dataset using one or more of the features in another dataset. Can be used to create a date set for study area or area of interest

Question 14

Dissolve

Answer 14

used to combine similar features within a data layer. Usually applied based on a specific attribute associated with each feature

Question 15

BUFFER

Answer 15

a region that is less than or equal to a specified distance from one or more features.

Question 16

Vector Buffer

Answer 16

may be applied to point, line, or area features and always produces an output set of area features.

Question 17

Buffer vector types

Answer 17

simple buffer (overlap dissolved)
Compound buffer (overlap identified)
nested buffer (multiple overlap layering)

Question 18

Buffering on vector lines steps:

Answer 18

First, circles are created
Second, are centered at each node or vertex
Third, tangent lines are generated

Question 19

Silvers are

Answer 19

a common feature representing the same phenomenon. This polygons cause problems because there is an entry in the attribute table for each polygon.

Question 20

Reducing slivers by

Answer 20

identifies all common boundaries across different layers. replacing the less accurate representations and substituting with the highest coordinate accuracy

Question 21

Proximity analysis

Answer 21

designed to examine spatial relationships such as the distance between features of interest