In waterways such as the Sacramento – San Joaquin Delta in the Central Valley of California, invasive water weeds have serious impacts from threatening biodiversity through to restricting access for leisure boating activities. The Delta covers an area of several thousand square kilometers with a requirement to both map water weed species and to evaluate the effectiveness of control measures.
From 2004 through to 2019, HyVista Corporation has acquired HyMap hyperspectral imagery over an area of 3500 sq km at a spatial resolution of 3m. The company delivered seamless reflectance mosaics to UC Davis for subsequent spectral-based analysis which successfully identified and mapped a number of invasive water weed species. Multiyear imagery allows one to efficiently monitor weed development on a multi-species basis across the entire Delta. The image inset shows the temporal variation of water hyacinth (green), pennywort (yellow) and water primrose (mauve) in Stone Lake. Non-vegetated water is indicated by blue.
Other demonstrated environmental applications include