1. Intro. To GIS Pre-Lab Spatial Analysis April 1 st, 2013

2. Spatial Analysis The application of operations to coordinate and related attribute data Maps are great, but this is the real power of GIS Spatial analysis is used to explore or solve a problem using a variety of geoprocessing tools

3. Calculate Geometry Length, Area, or X,Y coordinates Choose coordinate system of source or data frame Pick units of measurement Make sure field has units in the name

4. Types of Analysis Layer 1Function 1Layer 2Function 2Layer 3 Function Layer 2 Layer 1 Layer 3

5. Dissolve Tool – Similar to the merge function in Editor toolbar

6. Dissolve Tool Input Features Output Feature Class Dissolve field(s) (optional) Statistics (optional) Create multipart features (optional)

7. Buffering Buffering creates a polygon using a specified distance from a point, line, or other polygon

8. Buffer Tool Input Features Output Feature Class Distance – Linear unit (pick units) – Field (attribute table) Side/End type Dissolve Type

9. Buffer application 500 ft. buffer applied to houses Buffer overlaps transfer station

10. Multiple-Ring Buffer Creates buffers for many distances at once Dissolve option makes them non-overlapping

11. Near Tool Calculates distance from input features to nearest feature in other layer(s)

12. Near Tool Output has field with ID and distance of feature Multiple near layers can be calculated at once Options to include: – Location (X,Y) – Angle (degrees)

13. Intersect Polygons split at feature boundaries of both datasets Only overlapping areas are kept Attribute tables are combined in output

14. Identity Similar to intersect but input features are not clipped Features split along identity polygon edges Attribute tables are combined in output

15. Union Like Intersect but both input and union features are retained Output features have attributes from both input and union layers

16. Intersect / Identity / Union Which function is which?