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

1. Intro. To GISPre-LabSpatial AnalysisApril 1st, 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

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?