This is an article from the Summer 2015 VPS. For more VPS articles, click here
The mapped distribution of submerged hydrilla using VARI (Visible Atmospherically Resistant Index) in Lake Seminole along the Georgia-Florida border in November 2014. Image Credit: Southeast U.S. Ecological Forecasting Team
Category:åÊDetecting Habitat Conservation and Species Distribution
Project Team: Southeast U.S. Ecological Forecasting
Team Location: University of Georgia – Athens, Georgia
Authors:
Shuvankar Ghosh
Peter Hawman
Wuyang Cai
Elizabeth Dyer
Pradeep Kumar Ragu Chanthar
Mentors/Advisors:
Dr. Deepak Mishra (University of Georgia)
Dr. Susan Wilde (University of Georgia)
Abstract:
Hydrilla verticillata is an invasive aquatic plant that has become a serious problem in Southeastern United States, especially impacting vegetation and water quality. Traditionally, hydrilla infestation has been tackled using a combination of field-based physical, chemical and biological methods which are often costly. Rapid and accurate spatio-temporal estimates of hydrilla density and distribution are needed for better monitoring and management of this invasive plant. This project demonstrated an innovative approach using Landsat 8 OLI data to study the spread of this invasive aquatic plant in inland waters. NASA Landsat 8 Operational Land Imager (OLI) imagery in combination with in-situ data was used to map hydrilla density and distribution in four lakes across Georgia and Florida. Performances of Visible Atmospherically Resistant Index (VARI) and Green Normalized Difference Vegetation Index (GNDVI) were analyzed for indications of hydrilla density and distribution, using a combination of statistical techniques, such as coefficient of determination (R2), percent normalized root mean square error (%RMSE), and residual trends. The resulting detection tool for monitoring hydrilla distribution was delivered to Georgia Power, the J. W. Jones Ecological Research Center, and the Henry County Water Authority for use in water quality restoration decision-making. This tool will be an efficient alternative to otherwise costly measures, and facilitate adaptive plant management.