Introduction to ArcGIS for Environmental Sciences Day 2 – Fundamentals Module 8 Creating & Editing Data Creating Met

1. Introduction to ArcGIS forEnvironmental SciencesDay 2 – FundamentalsModule 8Creating & Editing DataCreating Metadata

2. Chapter 8 Objectives • Describe Steps in Editing Process • Move and Delete Features • Edit the Shapes of Line and Poly features • Create New Features by Digitizing • Edit Feature Attributes • Create Metadata

3. EPA Examples of Creating and Editing Data • Improving facility locations • Delineating site boundaries • Illegal filling of wetlands • Landfill expansion • Mapping unregulated facilities to conduct inspections (GW Compliance) • Mapping permits not regulated by EPA to evaluate cumulative impacts (Env. Review)

4. Editing Feature Shapes • When editing the shape of a feature, you work with its sketch • The sketch represents the geometry of a feature • Segments • Vertices • When you edit a feature’s shape, you primarily modify the features vertices • You can move, insert or delete vertices • Editing the vertices will affect the segments • Changes you make to one feature’s shape may affect the shapes of other features if they are spatially related.

5. The Editing Process • Add the data you want to edit to your map • Add other layers for orientation and reference (e.g., aerial photography) • Display the Editor toolbar and start an edit session • Set the editing environment • Specify your editing target – the layer you want to edit • Specify the editing task (e.g., modify) • Enable additional settings (e.g., snapping) • Select the feature and display its sketch • Double-click a feature to show vertices and segments • Make your edits • Move, insert or delete vertices • Save your edits • Changes are not updated until you save your edits – save often

6. Creating New Features - Digitizing • Heads-up digitizing – tracing shapes on screen using another layer for reference (aerial photos) • Each time you click on screen, an x,y coordinate is recorded • To digitize, follow these steps: • Start an edit session and set editing env. (target layer, editing task and snapping environment) • Zoom to the feature you want to digitize on your base layer • Trace the outline of the feature, clicking to create each vertex • Save your edits

7. Editing Made Easier with Snapping • Snapping is used to make sure features connect properly with other features • Setting the snapping environment involves: • Setting the snapping tolerance – distance within which a feature is snapped to another feature (Editor menu Snapping  Options) • Setting snapping properties - vertices, edges or endpoints (Editor menu  Snapping Snapping Toolbar) • Specify the snapping priority - order of which layers get snapped to (Editor menu  Snapping Snapping Toolbar)

8. Maintaining Spatial Relationships - Topology • If two features are adjacent, connectedorcoincident with each other, editing the shape of one will change the other’s shape as well. • Examples: • Two adjacent land parcels • Roads and bus routes are coincident • Streams must remain connected • To maintain spatial relationships in ArcGIS, you can setup a map topology during an edit session. • A map topology defines spatial relationships among features and maintains them during editing.

9. Editing Feature Attributes • Follow the same process used for editing feature shapes • Start an edit session • Select the features you want to edit • Make the edits • Save the edits

10. Methods of Editing Attributes: The Attribute Dialog Box • Displays the attribute values of the selected features in the map • You can edit individual feature attribute values by typing, copying & pasting, or deleting • You can also make changes to all the selected features at one time

11. Methods of Editing Attributes: The Attribute Table • Manually edit feature attributes by typing, copying & pasting, or deleting • Use the Field Calculator to automate editing

12. Calculating Attributes with the Field Calculator • Available from the layer attribute table • Enter an expression that calculates values for selected features • Calculate values for numeric, text and date fields • Create expressions based on values in other fields

13. XTools Pro: Calculating Area, Perimeter, Length, Acres and more • Xtools Pro extends ArcMap and ArcCatalog's capabilities and streamlines many common data management functions • Editing Functions include certain table operations, data management and editing options • Under EPA’s corporate license, Xtools Pro can be installed on any EPA machine that has ArcGIS installed • Download from the Office of Technology Operations and Planning (OTOP) web site.

14. Metadata • Whenever you obtain/create data, you should also obtain/create metadata • Metadata – a document that describes your data • Contains information like: • Who created the data • Who is the point of contact • When were the data created • Description of the data (abstract, purpose, etc.) • Data quality (accuracy, completeness, coverage, etc.) • Use and access constraints • Confidentiality • How the data were processed and who did the processing • Attribute definitions • Distribution information and liability

15. Metadata: Why is it so important?

16. Metadata: Why is it so important?

17. Metadata: Why is it so important? • Without metadata, you don’t know much about the data except what the title tells you (sometimes something is better than nothing) • Without metadata, you have to take the data at face value • probably not defensible in court • this has been a problem with some imagery services • Without metadata, data can easily be misinterpreted by users, resulting in erroneous maps • Data may not even be usable without certain metadata like projection information or definitions for attribute codes

18. Creating Metadata • EPA Metadata Editor (EME) • Developed as an alternative to ESRI’s Metadata Editor • Much easier to use • Drop-down menu options • Default settings • Links to help files • Color coded items indicate whether they are optional or mandatory to pass EPA and FGDC metadata standards • Ability to edit Access database with personal contact information • Access to EME is from ArcCatalog • Download EME from EPA’s National Geospatial Program web site • Other Tools for Creating/Editing Metadata • ArcCatalog • XTools Pro

19. EPA Metadata Editor (EME)Basic Data Set Information (Tab 1)

20. EME Quality, Coord. System and Attribute Info. (Tab 2)

21. EME Distribution & Metadata Information (Tab 3)

22. Final Words on Metadata Important to document key points of data: • abstract • attribute definitions • limitations/quality • projection • point of contact