Massachusetts Institute of Technology
Department of Urban Studies and Planning

 

11.188: Urban Planning and Social Science Laboratory

11.205: Intro to Spatial Analysis (1st half-semester)
11.520: Workshop on GIS (2nd half-semester)

Lecture One Notes:
Overview of Course, GIS Principles, Elements of Maps, ArcGIS Basics

 

February 3, 2020

(Joe Ferreira with contributions from Visting Prof. Zhong-Ren Peng who taught the Fall 2003 class)

Course Overview & Logistics

·       Times and rooms: Wed. lecture (City Arena, 9-255, 2:30-4:00), Mon. lab (W31-301, 2:30-5:00)

      (Additional, optional lab time: Friday, 12:30-2:00 in 9-554)

·       Discuss: Syllabus/Lectures/Labs/Homeworks/Project/books & 11.205/11.520 option
more info on class website: http://web.mit.edu/11.188

·       Stellar website - only for lab exercises, homework, and test

     http://stellar.mit.edu/S/course/11/sp20/11.188/index.html

·        Next Monday: Go directly to the Room W31-301 lab at 2:30 PM

·        Prep before Monday's lab
-- Read GIS intro
-- Review Lisa Sweeney's slides;
-- Review newspaper or blog articles utilizing maps as part of a spatial analysis (and find new examples during semester)

Examples:

Questions to ponder: What does each map 'say'; Is the evidence convincing, diagnostic, misleading; Are the visualizations consistent with the story, appropriate, biased, sensitive to the spatial scale; What data and tools are needed to construct the visualization; What context is needed in order to interpret the maps appropriately

(1) The Geography of Voting - and not Voting: Washington Post, October 23, 2018:
https://www.washingtonpost.com/graphics/2018/politics/voter-turnout/?utm_term=.255ddace8f04

(2) The Great Gerrymander of 2012: New York Times, Sunday, Feb. 2, 2013

-- Article: http://www.nytimes.com/2013/02/03/opinion/sunday/the-great-gerrymander-of-2012.html?pagewanted=all&_r=0
-- Graphic: http://www.nytimes.com/interactive/2013/02/03/sunday-review/imbalance-of-power.html?ref=sunday

(3) The Geography of Government Benefits: NYTimes, Feb. 11, 2012
http://www.nytimes.com/interactive/2012/02/12/us/entitlement-map.html

(4) Mapping Poverty in America: NYTimes, Jan. 4, 2014
http://www.nytimes.com/newsgraphics/2014/01/05/poverty-map/

(5) '9 Use of Google Maps Street View' in technology blog 'gizmodo':
http://gizmodo.com/you-are-here-the-13-best-maps-of-2013-1490022952

(6) Tricking Google Maps to think there is a traffic jam:
https://www-vice-com.cdn.ampproject.org/c/s/www.vice.com/amp/en_us/article/9393w7/this-man-created-traffic-jams-on-google-maps-using-a-red-wagon-full-of-phones

Today's Agenda:

 

·       Who are we in the class (fill out signup sheet)

·       Background and motivation: Where does learning GIS fit in

·       11.188 as an "urban planning and social science lab" that meets Institute lab requirement

·     11.205 to meet MCP spatial analysis requirement

·       Review online syllabus, lecture / lab schedule, assignments, etc.

·    Explain 11.205 + 11.520 half-semester parts for graduate credit

 

Examples to view and discuss:
... which are GIS? what to learn? how to add your own data/analyses?

  • Spatial analysis using commercial GIS software
    • Lisa Sweeney's Introduction to GIS and GeoProcessing: :Introduction to GeoProcessing Presentation
    • In Lab #1: use ArcGIS to do thematic mapping of Cambridge block groups and overlay results on Google Earth.
      • Still little spatial analysis (only simple thematic mapping) and mostly visualization of geographic patterns
    • Spatial analysis examples
      • which Cambridge housing sales are in low-income neighborhoods, in flood plains, near major roads...
      • That is, use proximity calculations to combine data from independent sources as part of an analysis
  • Private sector mapping services - try these on your own
    • Mapquest, Apple Maps, Bing. or Google-Maps to find a location and generate a street map: www.mapquest.com, www.bing.com, maps.google.com
    • Google-Earth or Virtual Earth to navigate and 'fly' over the earth: earth.google.com
      • Note overlays of vector (roads), raster (imagery), 3D (buildings) and mashups of user-generated data
      • Explore user interface (managing 3D view) and virtual earth's "bird's eye" view (using pictometry data)
      • Explore use of SketchUp to add your own 3D models
    • SmartPhone navigation and GPS-based tracking (e.g., google maps, foursquare, and other tracking apps)
  • Web services using proprietary or open-source (LAMP) tools

Evolution of GIS: A Timeline from 1970s to now



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    GISytems, GIScience, GIStudies, GIServices, Spatial Analysis, Urban Analytics...

    • GISystems – A computerized tool that helps solve geographic problems.
    • GIScience – The development of data models, algorithms, and methods for representing geography and spatial relationships in order to support spatial analysis and location-based computing
    • GIA - Geographic Information and Analysis
    • GIStudies – the systematic study of society’s use of geographic information, including institutional, organizational and procedural issues.
    • GIServices – The business of providing GIS data and analysis tools to GIS users (often by chaining interoperable components in lego-block fashion).

Example GIS Applications - think about useful data models for each example

  • Resource inventory (what is available where?)
  • Thematic maps (spatial pattern of population density, income, household size, etc.)
  • Network Analysis (How to get somewhere by road in the shortest amount of time?)
  • Location Analysis (Where is the 'best' place to locate a shopping mall?)
  • Terrain Analysis (What is the danger zone for a natural disaster? What can be seen from here [visibility analysis])
  • Spatio-Temporal Analysis (Land use: what has changed over the last twenty years, and why?)
  • Runoff models (If it rains 1 inch in 3 hours, how big is the storm surge at the bottom of the hill?)

ArcGIS Basics-- review of Lab Exercise 1

Overview of ArcGIS software (with Lab #1 exercise on-screen)

  • We will map Cambridge home sales and household income
  • Here is a screenshot of ArcMap with several data layers and web services in the table of contents

lab1 arcmap screenshot with web services

Things to think about

  • Explore elements in table of contents
    • Some are 'web services' in the cloud
    • Some are shapefiles (stored locally on disk)
    • How are spatial features modeled and linked to textual information about them
  • What are the various parts of ArcGIS and what do they do
  • How is ArcMap organized
  • Can you utilize ArcGIS Help effectively
  • How can a problem be split into operations that utilize the underlying 'vector' and 'raster' data models
    • E.G., which Cambridge housing sales occurred in low-income neighborhoods

 

For consideration in lab this week and next

  • Setting Up a Work Environment
    • Starting ArcGIS
    • Setting up workspace, scratchspace, database, etc.
  • Getting Data Into ArcMap
    • Data Frame Properties: Name, Units (Map, Display)
    • Layer Property
    • Tool in/out
    • Attribute Data
  • Basic Map Making
    • Simple Symbolization
    • Thematic Symbolization
  • Saving Your Work and Printing Output
  • Explore cross-referencing of map and data tables
  • Discuss data model for geometry and attributes
  • Compare uses of ArcMap with those of Mapquest and Google Earth

Elements of the Map

  • Scale (Distance on the map compared with distance on the earth)
  • Symbolization
  • Projection (Euclidan coordinate system instead of Lat/Lon)
    • ... Ignore projections for today and jump into ArcMap to get a feel for key features of a typical GIS package
    • ...We'll pay more attention to maps, data models, and ArcGIS basics in other lectures or in lab

 

Data Models -- How to encode Geometry and Geography

  • Model spatial objects by describing their boundaries (VECTOR data models)
    • Use coordinates that locate the spatial objects on the Earth
    • Point--a single XY location is often sufficient
      • MBTA Stops
      • Is Boston a point?--At different scales or for different purposes, Boston could be a point or polygon.
    • Line--only one dimension needs to be represented
      • Street centerline, MBTA Railroad track, ridgeline, bus route
      • How does it matter if street is modeled as centerline or as the void between blocks?
    • Polygon--2D planar surfaces
      • Cambridge border, central square boundary, census tract, parcel, ...
      • What about river boundary, edge of ocean (at high tide?)
    • Beyond planar surfaces - terrain models, 3D CAD models, ...
    • Link Attribute TABLE to spatial objects
      • Assign Object ID to each spatial object
      • Each row in attribute table links object ID to attributes of that object (census tract, zip code, ...)
  • Model the space that contains spatial objects (RASTER data models)
    • Divide space into 'cells' and encode whether a spatial object is in each cell
    • 30m x 30m grid cells for Landsat image - classified based on predominate land use within each cell
    • 6 inch pixels for color orthophotos developed from aerial photography
    • 3 km x 3km x 1 km (height) volumes (voxels) for meterological modeling

What does it mean to be "doing GIS"?

  • using the tools of Geographic Information Systems to solve a problem
    • urban planning relevant contexts were described above
    • a GIS project might have the following stages:
      1. define the problem
      2. acquire the software (and the hardware? or network resources?)
      3. acquire the data
      4. clean the database
      5. perform the analysis
      6. interpret and present the results
      7. institutionalize the process so that the analysis can be routinely redone
  • GIS tools and techniques are becoming more integrated with other tools and/or embedded in web services
    • Do spatial analysis without being 'in' a GIS package
    • Include location, spatial indexing, etc. in general purpose database management tools

[Lecture #1 presentation is expected to stop around here...]

 

Additional notes on 'Vector' data models for geospatial location

    • Geometry model:
      • boundary representation 'vector' model of spatial features
      • assign spatial feature ID to each spatial object within each map 'layer'
      • points (sales), lines (streets), and polygons (block groups)
        • Separate X,Y data for every part of every feature
        • Shared X,Y data for shared points and boundaries
    • Attribute data model
      • relational tables linked to spatial features via feature-ID
      • graphical interface to utilize geometry/attribute links
        • highlight map features by selecting attribute table rows
        • highlight attribute table rows by selecting map features
    • More than one way to represent the geometry: shape detail, shared boundaries, ...
      • ArcGIS shapefiles are the simplest and most common vector model
        • Only one feature type per shapefile
        • Several (4+) files on disk for each shapefile: cambbgrp.xxx
      • ArcGIS coverages use a more complicated data model
        • Data model includes topology, shared boundaries, ... (illustrate difference)
        • Geometry stored in sub-directory: cambtigr and sales89
        • Attributes stored in local database: in shared info sub-directory
    • Complications
      • islands, lakes, overpasses
      • shared edges?, do attached links move when you move points?
      • ambiguity: summer/winter wetland boundaries
      • scale, generalization, conflation, slivers
      • Coordinate systems and projections
      • One-to-many relationships among spatial features and events
    • Thematic mapping - tip of iceberg regarding GIS applications
      • Symbology
        • many options
        • review 'symbology' page of layer properties
        • review ArcGIS help files for symbology
      • Different classification schemes (show help page):
        • Equal Interval
        • Natural Breaks
        • Quantile
        • Standard Deviation
      • Normalization: people or population density - Why do we care? (show examples)

For MONDAY - go directly to the lab (Room W31-301) at 2:30 PM

 


Created by Prof. Zhong-Ren Peng, September 2nd, 2003.
Modified by Jinhua Zhao, September 7th, 2004.

Last Modified by Joseph Ferreira, Jan. 31, 2020.

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