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Detecting Cheatgrass on the Colorado Plateau Using Landsat Data: A Tutorial for the DESI Software

By Raymond F. Kokaly

Invasive plant species disrupt native ecosystems and cause economic harm to public lands. In this report, an example of applying the Detection of Early Season Invasives software to mapping cheatgrass infestations is given. A discussion of each step of the DESI process is given, including selection of Landsat images. Tutorial data, covering a semi-arid area in southern Utah, are distributed with this report. Tips on deriving the inputs required to run DESI are provided. An approach for evaluating and adjusting detection parameters by examining interim products of DESI is discussed.

First posted February 04, 2011 Report PDF (23.1 MB) Downloads Directory (1.85 G) For additional information contact: USGS Crustal Geophysics and Geochemistry Science Center Box 25046, Mail Stop 964 Denver, CO 80225 http://crustal.usgs.gov/ This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Kokaly, R.F., 2011, Detecting cheatgrass on the Colorado Plateau using Landsat data: A tutorial for the DESI software: U.S. Geological Survey Open-File Report 2010–1327, 88 p.

Contents

Abstract

Introduction

Recommended Image Dates for Cheatgrass Detection

Acquisition of Landsat Images

Processing Landsat Data to Map Cheatgrass

Converting Data from Raw Digital Number to Radiance

Converting Data from Radiance to Reflectance

Generating a Mask for Clouds/Snow, Water, Shadows, and Burned Areas

Checking Geographic Agreement Between Early-Season and Midsummer Images

Calculating NDVI

Calculating dNDVI

Creating and Evaluating the Cheatgrass Maps

Acknowledgments

Release Notes

References Cited

Appendix A

Appendix B

Appendix C

Appendix D