1 / 21

Spatial analysis 101

Spatial analysis 101. Megan Brown Water Availability Division. Mission Goals. Mission Outline: Introduce the Spatial Analyst extension Tour of most useful tools Demo Mission Goals: Understand the basic theories behind spatial analysis Conduct basic analysis

musick
Download Presentation

Spatial analysis 101

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Spatial analysis 101 Megan Brown Water Availability Division

  2. Mission Goals • Mission Outline: • Introduce the Spatial Analyst extension • Tour of most useful tools • Demo • Mission Goals: • Understand the basic theories behind spatial analysis • Conduct basic analysis • Ability to confidently explore new tools independently

  3. What is Spatial Analysis? • Spatial analysis encompasses all the operations performed on geographic data that add value • The single most defining characteristic of spatial analysis is its location-dependent nature • New information is generated by identifying patterns that relate data characteristics (attribute table) to the data’s spatial characteristics (geographic location)

  4. Thinking About spatial analysis • Normative analysis – identify best solution to a spatial dependent problem Where is the best location to put the thing, based on factors X, Y and Z? • Deductive analysis – test existing theories or principals, validity of relationships Do occurrences of risk factors correlate with occurrences of an outcome? • Inductive analysis – discern patterns Is there a spatial trend or clustering to the things?

  5. Spatial Analyst toolbox

  6. Be BraveYou are not going to break it • Do not be afraid to experiment with data and new tools!! • Remember, the original data is not altered when a tool is run. A new data output is generated. • You can always delete outputs and try something else. • Keep “test data” to experiment with • Usually means having a separate location with copies of datasets • You might create dummy test data • If your test data gets messed up you can always: • delete it • start with a fresh copy • nothing lost!

  7. Tool Help The tool help button on any tool will take you to ESRI’s comprehensive online searchable data dictionary explaining all of the standard tools and the calculations they utilize.

  8. Surface Tools Demo Examples: Slope Viewshed

  9. Slope

  10. Viewshed Note: Viewshed doesn’t necessarily make pretty outputs. In order to discern the maximum amount of information, being mindful about your layer stacking and transparency settings as well as color contrast is important. We can see here that the point selected is in a low spot, and the viewshed highlights the surrounding cliff faces as the only visible features on the slope raster.

  11. Hydrology Tools

  12. Delineating a Watershed

  13. Groundwater Tools Groundwater requires very complex data inputs. We won’t be demonstrating any examples of our own today, but below for your reference is a url to ESRI’s forum on groundwater analysis. If this applies to you, I encourage you to explore it further.

  14. Density Tools Great tool set for finding “hotspots” or analyzing demographic data

  15. Point Density

  16. Applied Demo: Site assessment for water testing station • Step 1-- Identify limiting factors • Slope • Proximity to stream • Floodplain • Proximity to roads for access • Within 3 miles downstream of point of interest • Step 2 – Acquire data • Acquire a local DEM • Stream, floodplain, roads layers • Coordinates of POI • Step 3 – Outline Process • Generate slope • Buffers for proximity • Convert vector to raster • Reclass • Weighted Overlay • Step 4 -- Choose Processing Method • By hand, one step at a time? • Model Builder? • Python script? • Step 5 – Spatial Analysis

  17. Site Suitability Analysis

  18. Site Suitability Analysis

  19. Choose A Site If orange denotes areas that meet our criteria, where would you put your site(s)?

  20. Take Away Wisdoms • Spatial analysis is a way to analyze data based on it’s spatial relationships • Spatial Analyst holds a plethora of useful tools • Tool Help is an invaluable resource • Some tool sets are designed to work together • Complex tools aren’t scary • Don’t be afraid to try new things!

  21. Questions Contact Info: 512-239-2248 Megan.Brown@tceq.texas.gov www.LinkedIn.com/in/brownmegane

More Related