Mapping Phragmites australis Live Fractional Cover in the Lower Mississippi River Delta, Louisiana

Open-File Report 2020-1131
Prepared in cooperation with the U.S. Fish and Wildlife Service
By: , and 



In response to a co-occurring non-native scale infestation and Phragmites australis dieback in southeast Louisiana, normalized difference vegetation index (NDVI) satellite mapping was implemented to track P. australis condition in the lower Mississippi River Delta. While the NDVI mapping successfully documented relative condition changes, identification of cause required a quantitative-biophysical metric directly related to P. australis marsh live vegetation proportion. During this study, a satellite mapping tool that quantified P. australis live fraction cover (LFC) magnitude was designed and implemented. The key to development of the quantitative LFC mapping was the field to satellite calibration design. The calibration of P. australis marsh LFC to optical satellite image data combined field and near-in-time satellite data collections in the fall of 2018 and summer of 2019. Basing the field-NDVI to field-LFC calibrations and the satellite-NDVI to field-NDVI calibrations on combined pre-senescence and peak-growth period data offers nearly year-round LFC mapping. The utility of the developed P. australis marsh LFC mapping tool was demonstrated by the creation of a yearly suite of Mississippi River Delta LFC status and change maps extending from 2009 to 2019. P. australis marsh LFC mapping relies on Sentinel-2 for current to future mapping and relies on Landsat for historical mapping.

Suggested Citation

Rangoonwala, A., Howard, R.J., and Ramsey, E.W., III, 2020, Mapping Phragmites australis live fractional cover in the lower Mississippi River Delta, Louisiana (ver. 1.1, January 2021): U.S. Geological Survey Open-File Report 2020–1131, 24 p.,

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Study Area
  • Methods
  • Results
  • Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Mapping Phragmites australis live fractional cover in the lower Mississippi River Delta, Louisiana
Series title Open-File Report
Series number 2020-1131
DOI 10.3133/ofr20201131
Edition Version 1.0: December 14, 2020; Version 1.1: January 27, 2021
Year Published 2020
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Wetland and Aquatic Research Center
Description Report: vii, 24 p.; Data Release
Country United States
State Louisiana
Other Geospatial Lower Mississippi River Delta
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details