Map Overlay: Some examples

Objectives of Lecture:

1. Prepare for Case Study discussions (next week)
2. Discuss projects (P0: due next week!)
3. Prepare for Exercise 3; process diagrams
4. Review lectures on overlay
5. Continue with examples

Projects

Basic structure set out in Course Policies; more in Project description

Now is the time to create a team and pick a topic. Yes this involves thinking about data sources available, but there is no time like the present to get started...

Process Diagrams

There are a lot of ways to keep track of what operations you have performed/ will be performing. Any technique that works for you and your team is probably good enough. For the purposes of this class, we want to help you work with diagrams beginning with Exercise 3.

What to record in a process diagram:

• Data Source(s) [number depends on kind of operation]
  name
  location on disk (path)
  attribute tables (columns)
• Operations performed
  tool, parameters (equations to Calculator, etc.)
  Does this increase or decrease the information? (just a thought-experiment)
• Results produced
  Name of layer (DO NOT stick with the default labels like Calculation! "thatmap", or default labels), attribute tables...
  Type of coverage (grid, shapefile, image, etc.)
  Where you saved it (path)
  Purpose: what you thought you were doing...
  

You can get more creative in terms of layout... but the content is what will save you effort.

Overlay: More examples

Background, Geometric calculations; Attribute Rules for Combination; Resources about overlay

[Examples presented from overheads]

Low-level radioactive waste repository siting

• Federal requirements:
• Local Implementations:
  • Pennsylvania Low Level Radioactive Waste siting:
    Overview
    Data Sources
    • More details
  • New York

Use of overlay to examine accuracy of sources

• Pierce County Critical Areas process (ESRI Conference paper)
•  

An over simplified example: Locate a Balloon Launch Facility

Blast from the past! Running Map II on a Mac IIci... Map II is a relative (like a long lost uncle?) of Sptail Analyst; They are all progeny of MAP package.

Method 1: Black/White Exclusions

Balloon launch cannot be within 1000 feet of electric power transmission lines.

Balloon launch cannot be within a wetland, river or lake.

Balloon launch cannot have tree cover or houses.

Balloon launch must be flat.

Method 2: Take the worst factor in the cell (No risk < some risk < large risk)

Large: within 300 feet of electric power transmission lines, some within 1000

Large: lake, river

Some: wetlands

Large: Old growth, mature trees, urban

Some: shrubs, etc.

No: farm fields, unmowed grass, etc.

Slope classed 0-5%, 5-10%, 10% and up.

Method 3: Rating and Weighting (lots of variations)

Distance electric power transmission lines.

Wetland, river or lake.

Tree cover or houses.

% slope