GIS in Real Estate Phil Hurvitz CAUP-Urban Form Lab April 13, 2005

GIS in Real Estate 2 Overview What is GIS? How is GIS used outside of real estate Data models used in GIS Lab session_

GIS in Real Estate 3 Overview What is GIS? How is GIS used outside of real estate Data models used in GIS Lab session

GIS in Real Estate 4 What is GIS? GIS is a computer-based technology used for the –Capture –Storage –Manipulation –Analysis, and –Display of spatially referenced data_

GIS in Real Estate 5 What the hell does that mean? Anything you have ever seen, or could imagine on a map can be stored and analyzed with specialized software on a desktop PC (Examples to follow)…_

GIS in Real Estate 6 Why use a GIS? An extension of the paper map, but much more than a map, as you will see GIS uses the analytical power of the computer to complete complex tasks Computer's storage power to manage large data sets. Integration of many different types of data from many different sources GIS maps a variety of different data to the same coordinate space (allows for combination of data)_

GIS in Real Estate 7 What are the necessary parts to a GIS? 1.Trained personnel (the most expensive part) 2.Software (at the high end, ArcGIS, ~$25,000 per seat) 3.Data (many for free, some cost $$) 4.Computers (even a moderate desktop PC these days can perform dazzling things) 5.Ideas!_

GIS in Real Estate 8 Overview What is GIS? How is GIS used outside of real estate Data models used in GIS Lab session

GIS in Real Estate 9 GIS use examples in various disciplines Natural resource management Telecommunications “Traveling salesman” problem Risk management & emergency response Space exploration Urban form & Public Health

GIS in Real Estate 10 Natural resource management Where are areas on a forest that meet a given complex set of criteria? –“What parts of the forest are located: –within 100 ft of a stream, –beyond 50 ft from a road, –on greater than 30% slope?”

GIS in Real Estate 11 on > 30% slope? closer than 100 ft to a stream, and farther than 50 ft from a road,

GIS in Real Estate 12 Telecommunications Cellular phone towers

GIS in Real Estate 13 Telecommunications Cellular phone towers

GIS in Real Estate 14 Telecommunications Cellular phone towers

GIS in Real Estate 15 “Traveling salesman” problem

GIS in Real Estate 16 Space exploration

GIS in Real Estate 17 Urban form & Public Health Urban sprawl and automobile dependence –decreased activity levels –increased obesity rates Is urban spatial composition and configuration and indicator for obesity or other disease? Can communities be structured to promote an increase in activity levels? GIS is a central tool in quantifying the urban environment

GIS in Real Estate 18 Walkability & Bikeability Modeling WBC Project, funded by CDCs Urban Form Lab (Anne Moudon, Chanam Lee) A GIS extension for obtaining environmental data in a household’s neighborhood –Urban features within walking/cycling distance –200+ variables per household –Stat

GIS in Real Estate 19 Walkability & Bikeability Modeling

GIS in Real Estate 20 What is in the neighborhood? 3 banks 1 km radius 1 bar

GIS in Real Estate 21 How do land uses cluster?

GIS in Real Estate 22 Overview What is GIS? How is GIS used outside of real estate Data models used in GIS Lab session

GIS in Real Estate 23 Spatial Data Model: Basic Data Types GIS are driven by spatial data 2 basic spatial (coordinate/geometric) data models exist –vector: based on geometry of points lines polygons –raster: based on geometry of grid cells (images, bitmaps, DEMs)_

GIS in Real Estate 24 Vector Data Model Points: represent discrete point features each point location has a record in the table airports are point features each point is stored as a coordinate pair

GIS in Real Estate 25 Vector Data Model Lines: represent linear features roads are linear features each road segment has a record in the table

GIS in Real Estate 26 Vector Data Model Lines: fundamental spatial data model Lines start and end at nodes line #1 goes from node #2 to node #1 Vertices determine shape of line Nodes and vertices are stored as coordinate pairs_ node vertex

GIS in Real Estate 27 Vector Data Model Polygons: represent bounded areas each bounded polygon has a record in the table landforms and water are polygonal features

GIS in Real Estate 28 Vector Data Model Polygon #2 is bounded by lines 1 & 2 Line 2 has polygon 1 on left and polygon 2 on right_ Polygons: fundamental spatial data model

GIS in Real Estate 29 Vector Data Model complex data model, especially for larger data sets “arc-node topology,” only used for ArcInfo data sets_ Polygons: fundamental spatial data model

GIS in Real Estate 30 Raster Data Model digital orthophoto digital elevation model (DEM)_ A few different types of raster data

GIS in Real Estate 31 Raster spatial data model origin is set explicitly cell size is always known cell references (row/column locations) are known cell values are referenced to row/column location values represent numerical phenomena or index codes for non- numerical phenomena_

GIS in Real Estate 32 Raster Data Model Characteristics of the raster data model: –Rectangular grid of square cells – Shape of discrete polygonal features generalized by cells + Continuous (surface) data represented easily + Simple data structure_

GIS in Real Estate 33 Raster Data Model Raster data are good at representing continuous phenomena, e.g., –Wind speed –Elevation, slope, aspect –Chemical concentration –Likelihood of existence of a certain condition –Electromagnetic reflectance (photographic or satellite imagery)_

GIS in Real Estate 34 The “where” of GIS is determined by coordinate (map) data structures, but … The “what” of GIS is determined by tabular (relational database) data structures Thus, tabular data are just as important as coordinate data_ Relational Database Model & Attribute Data Structures

GIS in Real Estate 35 Relational Database Model & Attribute Data Structures Attribute data are stored in database tables. Tables are composed of: –fields and –records_

GIS in Real Estate 36 Relational Database Model & Attribute Data Structures You may already be familiar with some types of relational databases –dBase –rBase –MS Access –MS Excel (database functionality) –Oracle, INFORMIX, INGRES, SQL Server –MySQL, PostgreSQL –INFO (in ArcInfo)_

GIS in Real Estate 37 Relational Database Model & Attribute Data Structures Each vector data source has an attribute table

GIS in Real Estate 38 Relational Database Model & Attribute Data Structures Tables can be linked and joined (“related”) by use of common values in fields

GIS in Real Estate 39 Relational Database Model & Attribute Data Structures Relationship between tabular and map data –one-to-one between features and records when a selection is made, both the record and feature are selected

GIS in Real Estate 40 Overview What is GIS? How is GIS used outside of real estate Data models used in GIS Lab session

GIS in Real Estate 41 Lab Session Open GIS software Download Seattle & King County data Perform query & display Create a map displaying a simple selection or analysis