gtech 361 lecture 07 secondary data. geodatabase topology rule-based

GTECH 361

Lecture 07

Secondary Data

Geodatabase Topology

Rule-based

Geometric Networks

Editing With Topology

Relationship Classes

Types of Geodatabases

Personal GDB

Enterprise GDB

Inside the Geodatabase

Now to the Session Proper

Secondary data sources

US Census

Geo data portal

Why Secondary Data?

Context (geographic, temporal, social) for primary data

Secondary data may provide validation for primary data

Secondary data may act as a substitute for primary data

Unofficial Secondary Data Sources

Private research results Research reports, research papers,

textbooks Opinion polls Market research On-line databases Anecdotal/hearsay

Official Secondary Data Sources

Agriculture Business/

Industry Crime Education Finance

Energy Environment Health Transport Weather

Agriculture

USDA

FAO

Farm Bureau Federation

Babcock

Business / Industry

STAT-USA/Internet (US Dep. of Commerce, not free)

Consumer Expenditure Surveys(Bureau of Labor Statistics)

Internal Revenue Service

Crime

Bureau of Justice Statistics

FBI

Crime & Justice Electronic Data Abstractshttp://www.ojp.usdoj.gov/bjs/dtdata.htm

Education

National Center for Education Statistics

School District Data Book (ORST)

National Science Foundation

UNESCO

Environment EPA Envirofacts EPA EnviroMapper

Facility Information Hazardous Waste Data Superfund Toxics Releases Inventory Water Discharge Permits

ScoreCard Right To Know

Health

National Center for Health Statistics (CDC)

Social Security Administration

Geophysical

NOAA

USGS

US Forest Service

Soil Conservation Service

Dep. of Natural Resources (DNR)

Dep. of Conservation

Transportation

Department of Transportation

Bureau of Transportation Statistics

State Highway Departments (CA, TX)

Regional Transport Authorities

Census Structure Timing Population Organization Analysis Presentation Geographical Hierarchy Variables

Historical Context

Article I, Section 2 of the U.S. Constitution adopted in 1787 approved that Representatives and Taxes shall be apportioned among the states according to each states population.

Enumeration (to ascertain the number of: count) shall be made within every subsequent term of 10 years

The first Census of Population was conducted in 1790, it counted 3.9 million people and increased representation in the House to 105.

As the Nation’s needs and interests became more complex statistics were added to help people understand what the raw numbers meant.

Historical Context

What is Collected? In 1954 Title 13 of the United States

Code brought together the laws under which the Census Bureau operates

This included a law requiring the following Censuses to be conducted:

Population, housing, manufacturers, mineral industries, other businesses, construction, transportation, and governments at stated intervals

Confidentiality The sole purpose of the censuses is to

secure general statistical information. Replies are obtained from individuals and establishments only to enable the compilation of these general statistics

By law, no one is permitted to reveal identifiable information

Before any information is published it is checked to make certain that no individual, household or organization can be identified

The individual forms filled out are closed to public viewing for 72 years

The Freedom of Information Act does not apply to identifiable census data

Confidentiality

Census 2000 Forms

2 main types, a short form and a long form The short form asks 7 questions 83% of households received the short form The long form covers 34 subjects 1 in 6 households received the long form The long form took approximately 38(?!)

minutes to complete

Why Two Forms? The short form The long form The data from the long form is

considered to be representative of all the people in the “neighborhood” and is extrapolated into sample data

The data from the short form is considered to count 100% of the population

Dealing with Census Data

The main way to tackle census data is by: Geographic extent of the area you are

interested in and Variables or subjects The key is to combine the two

Census Geography

It is confusing!

Changes over time

Some levels are based on population numbers

Do not compare oranges to apples!!

Census Geographic Areas

States, DC and Puerto Rico Counties Cities, towns, and townships Census tracts (roughly 4000 people,

neighborhood sized areas) Block groups (groups of census blocks,

generally containing 800 to 1,000 people) Blocks (9 million, covering entire US, not

all data is summarized to this level) Congressional districts American Indian and Alaska Native Areas

Census Geographical Hierarchy

Metropolitan Areas

Census Geography It is confusing! Changes over time Some levels are

based on population numbers

Do not compare oranges to apples!!

Census Household Variables

Number of persons Age and gender Race Language Income and

poverty Education Employment Citizenship

Vehicles for commute Disability Homeownership status Vacancy Rent and value of

housing Age and type of

structure Plumbing and Kitchen Heating

Examples of Census Variables

Accommodations Agriculture Alaska Natives Arts,

Entertainments Asians Assets Assistance

Capital Expenditures

Child Care/Support Commodity Flows Communications Consumer Income County Business

Patterns County/City

Government

The Concept of Race Not based on any scientific definition Prior to Census 2000 only allowed 1 choice Census 2000 allowed the following choices

for Race: White Black, African American American Indian or Alaska Native (tribe was

requested) Asian Indian, Japanese, Chinese, Filipino, Hawaiian,

Korean, Vietnamese, Guamanian or Chamorro Samoan Or to be written in if none of these apply

Ethnic Origin The Hispanic population is considered

an ethnic group according the the Census Bureau In Census 2000 choices for Hispanic origin

or descent were: Mexican Mexican American Puerto Rican Cuban Or Other Spanish/Hispanic/Latino

The concept of race separate from Hispanic origin has been confusing Census users for years

The thing to remember is that while a person may be of Hispanic origin, they also are white, black, asian-pacific islander, or other

It’s the same concept of being white and of german ethnicity

Race/Ethnic Origin

Multiracial Categories Controversy

Until 1970 the Census Bureau enumerator decided people’s race for them, sometimes by inquiring, often by simply looking

Since 1970 people could choose only 1 race to describe themselves

Census 2000 allowed people to choose any number of races

Over 7 million people marked more than one race to describe themselves

This number is less than 3 percent of the total population but has huge impacts in a number of ways

If one counts only those who checked American Indian alone, 2.5 million

If one counts those whites and blacks who think they have a little Indian blood, and checked it in addition to white or black categories, 4.1 million

That is an increase of nearly 65% Should the Federal Government

increase services for Native Americans by 65%?

Native Americans

Statistical Problems

The Census Bureau’s racial percentages now add up to well over 100

No one can reliably compare 1990 or earlier data to 2000 data

TIGER Topologically Integrated Geographic

Encoding and Referencing system

Based on USGS topographic maps but majorly augmented

Contains no elevation data

No copyright

No attribute data!

American Community Survey

Annual

Long

Representative – not comprehensive

Master Address File for sample selection

Wisconsin a forerunner

Pro’s and Con’s of Secondary Data

Advantages Cheap Timeliness Access to

people/organizations that we wouldn’t have access to otherwise

Less post-processing

Disadvantages

Collection method unknown

Lack of control

Geoinformation Portals

Public data (mostly federal)

http://www.geodata.gov/

Public and private data (sometimes

costly)

http://www.geographynetwork.com/

Data Vendors

Remote Sensing Value adding to public data Utilities Market Research GIS Vendors University Extensions World Bank

Before YOU Purchase Data

Accuracy

Compatibility

Lineage and metadata

Who owns the copyright?