How to Map Irrigated and Non-Irrigated Land on the Eastern Snake Plain Aquifer Quickly, Easily, and Well How to Map Irrigated and Non-Irrigated Land on the Eastern Snake Plain Aquifer Quickly, Easily, and Well Image Processing Bill Kramber Classification Editing Tony Morse CLU Editing Margie Wilkins

Outline Intro The Past The Present The Future of the Past

What, exactly, do you mean when you say, “Irrigation?” Irrigated all year long? Irrigated once or twice? Sub-irrigation? Entire field or only part? For now, if >75% of field irrigated on one date, then “Irrigated”

The Past 1980 RASA classification rasa80lc Landsat MSS 57 meter pixels Per point classifier with stratification 1992 BOR/IDWR classification Snakelc92 1:40,000 scale photos Several classes Digitized

rasa80lc

1980 RASA rasa80lc

snakelc92

Snake92cl

Point Both rasa80lc and snakelc92 over mapped irrigated.

The Present Classification Scheme 1. Edit and correct CLU polygons 2. Run a 3-Phase Classifier 1) Per Pixel using 3 dates of NDVI 2) Overlay CLU polygons 3) Aggregate pixels by CLU polygon 3. Manual Edit of Classification 4. Allan buys the beer CLU??

A Bit About CLU USDA/FSA Common Land Unit Generally correspond to agricultural fields Generated for federal crop support programs Only the polygons are available – not attributes Done for all Idaho counties, but need some editing.

3-Dates of NDVI Blue 6/20/2006 Green 7/22/2006 Red 8/7/2007 Cluster and Interpret spectral classes Phase 1: Per Pixel Classifier

Per Pixel Classifier Output

Phase 2: Overlay of CLU Polygons Polygon is “Irrigated” if polygon > 75% irrigated pixels

Phase 3: Aggregation by CLU Polygon Initial Classification

Before Editing

After Editing

Model Grid on final Classification

Point NDVI/CLU classification is better than Snakelc92

The Future of the Past Landsat Data Archive

2000

1990

1986

1984 MSS

Was it irrigated in 1992?

Unfinished Business Who wants to do it? Accuracy Evaluation

Snake River near Hagerman