Optimizing Remote Sensing and GIS Tools for Mapping and Managing the Distribution of an Invasive Mangrove (Rhizophora mangle) on South Molokai, Hawaii

Abstract

In 1902, the Florida red mangrove, Rhizophora mangle L., was introduced to the island of Molokai, Hawaii, and has since colonized nearly 25% of the south coast shoreline. By classifying three kinds of remote sensing imagery, we compared abilities to detect invasive mangrove distributions and to discriminate mangroves from surrounding terrestrial vegetation. Using three analytical techniques, we compared mangrove mapping accuracy for various sensor-technique combinations. ANOVA of accuracy assessments demonstrated significant differences among techniques, but no significant differences among the three sensors. We summarize advantages and disadvantages of each sensor and technique for mapping mangrove distributions in tropical coastal environments.

Keywords:

• AVIRIS
• ASTER
• aerial photography
• habitat mapping
• classification accuracy
• alien species management
• red mangrove

Acknowledgements

This study was conducted as part of the Coral Reef Project of the USGS Coastal and Marine Geology (CMG) Program, and we thank all members of this research team for their support and encouragement. We also thank the NASA JPL for funding and acquiring the AVIRIS 2000 Hawaii High Altitude data. We thank Dr. Michael E. Field (USGS—CMG) for initiating and guiding this study, Dr. Gary Griggs and Dr. Eli Silver for valuable editing insights and suggestions, and Jim Maragos, Bruce Richmond, Cheryl Hapke, Ann Gibbs, Josh Logan, and Curt Storlazzi of the USGS Pacific Science Center for invaluable assistance with image processing and GIS applications. Last, we thank other members of the Hyperspectral Imaging Project (HIP) and Coastal Imaging Lab at UCSC for ongoing academic advice and scientific collaboration.

Notes

*Non-digital, using film emulsion technology.

**High altitude AVIRIS flown at 20 km.

NS = not significant, ** = P <.01.

** = P < .01.