GIS for Air Quality

March, 2014Tribal Air Monitoring Support (TAMS) Center, Las Vegas, Nevada

Glenn Gehring, TAMS Technology SpecialistGlenn.Gehring@nau.edu, 541-612-0899 (cell)

Copy of slide from NAU’s Geographic Information Systems “GIS”: Geography Matters

Copy of slide from NAU’s Geographic Information Systems “GIS”: Geography Matters

A Central Database that can Analyze and Display Information From Many Databases, Holistically.

Copy of slide from NAU’s Geographic Information Systems “GIS”: Geography Matters

Fields (Columns)

XY

Records(rows)

XY Table(Create Feature Class from XY Table)

X

Y

Lines of Latitude

(Run east west but are measured on Y axis)

Lines of Longitude

(Run north south but are measured on X axis)

Why XY tables?

“Join” Cancer Data to Census Data by Matching FIPS

http://www.statecancerprofiles.cancer.gov/

Some BasicsFeature Classes (Vectors) vs. Rasters

Features are generally lines, points and polygons. Feature classes are groups of the same feature type. For example, a single road might be a line feature and a roads feature class includes many lines representing many roads. Feature classes have attribute data and each feature can have many attributes. Think of the xy table for points with a latitude and longitude spatially orienting the point on each row. IN addition to the location information there are many columns (fields) with information about the point on each row (site id, state id, concentration…)

Rasters are typically a series of squares on a grid. There can only be one value in each square. For example, a DEM raster would have 1 elevation value per square.

Location for grid on one square

Each square can only have one value.

Scale and Projection

I’ll just make one point about scale. Imagine a map drawn for the whole United States with Interstates on it. To see the Interstate on the national map the line must be fairly thick. Now imagine the actual Interstate at one location near you. That thick line might represent well over a kilometer of earth. Sure, we can make the line look thinner, but the actual location of the Interstate might be off due to the fact that it was initially drawn at the national scale. Certainly, small curves won’t align perfectly.

A Few GIS ExamplesTracking Wildlife

Remote sensing

Noxious weeds example

River eutrophication

Tribal Fisheries

Shrimp harvest example

Identifying where to drill a well or site a business

With GIS we do analysis and create images to better understand data. GIS is part science and part art. Your creativity is an important part of the GIS system.

Course Introduction

• An air quality course, not comprehensive GIS• 9 Exercises and morning afternoon discussions• Work at your own pace• If you complete all exercises early you can:

– Explore a high concentration in your area– Go online and read tutorials at relevant web sites– Google GIS terms and use help files to better

understand options used in this course– Expand and further explore the exercises using the

national map we provide

GIS Glossary

Download Site

http://itep68.itep.nau.edu/itep_downloads/

All exercises are in screen shots

Exercise 1

Exercise 2

Exercise 3

Exercise 4

Exercise 5

Exercise 6

Exercise 7

Exercise 8

Exercise 9

These course exercises can be used as guidance when using GIS in your area. When you finish the exercises you can begin exploring your area of interest.

Keep in mind that this course doesn’t address many nuances of using GIS software. Air quality specific courses in GIS are limited. There are many other GIS trainings available that can build your technical skills with GIS. We certainly encourage you to explore those additional training opportunities.