How to Map How to Map Irrigated and Non-Irrigated Land Irrigated and Non-Irrigated Land

on the on the Eastern Snake Plane AquiferEastern Snake Plane Aquifer

Quickly, Easily, and WellQuickly, Easily, and Well

How to Map How to Map Irrigated and Non-Irrigated Land Irrigated and Non-Irrigated Land

on the on the Eastern Snake Plane AquiferEastern Snake Plane Aquifer

Quickly, Easily, and WellQuickly, 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 classificationrasa80lcLandsat MSS57 meter pixelsPer point classifier with stratification

1992 BOR/IDWR classificationSnakelc921:40,000 scale photosSeveral classesDigitized

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 Classifier1) Per Pixel using 3 dates of NDVI2) Overlay CLU polygons3) Aggregate pixels by CLU polygon

3. Manual Edit of Classification

4. Allan buys the beer

CLU??

A Bit About CLUUSDA/FSA Common Land UnitGenerally correspond to agricultural fieldsGenerated for federal crop support programsOnly the polygons are available – not attributesDone 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 PolygonsPolygon is “Irrigated” if polygon > 75% irrigated pixels

Phase 3: Aggregation by CLU PolygonInitial Classification

Before Editing

After 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?

1992 2006

Unfinished Business

Who wants to do it?

Accuracy Evaluation

Snake River near Hagerman