joins and overlays

Question 1

spatial join

Answer 1

combining multiple datasets based on a spatial relationship based on the same operators used for spatial queries, the resulting feature class has the same geometry as the target class

Question 2

cardinality in spatial joins

Answer 2

each record in the target class can only have 1 row from the join class, must be one to one

Question 3

merge rules

Answer 3

can help with one to many joins by merging the many into a single feature

Question 4

one to many join operation

Answer 4

makes copies of the target features until they match the join features one to one

Question 5

merged join

Answer 5

when a target feature has multiple join features, merge rules should be created for each field

Question 6

classic overlay

Answer 6

combines 2 layers, crossing features are split forcing a one to one join, all boundaries are transferred to the output as new non overlapping features

Question 7

union

Answer 7

combines 2 polygon layers keeping all areas and merging attributes for both layers, used to evaluate combinations of attributes

Question 8

intersect

Answer 8

merges attributes and returns only the areas common in both layers, used for suitability analysis

Question 9

suitability analysis

Answer 9

evaluating a landscape to find which areas best serve a given purpose based on a set of constraints

Question 10

overlay geometry

Answer 10

input: polygons, output: points lines or polygons
input: lines, output: points or lines
input: points, output: points
input polygons and lines, output: points or lines

Question 11

slivers

Answer 11

logical consistency errors in overlays creating small extraneous lines or polygons, minimized via x,y tolerance

Question 12

x,y tolerance

Answer 12

specifies a minimum distance between vertices

Question 13

GIS models

Answer 13

visual diagrams that chart the process of answering questions with GIS