Citation:

Clinton, P. USEPA Newport Lab Aerial Photo Inventory. U.S. Environmental Protection Agency, Washington, DC, 2019.

Impact/Purpose:

EPA scientists at NHEERL/WED have amassed an archive of true-color and false-color-infrared aerial photographs of several Oregon estuaries, obtained between 1997 and 2006 to support multiple ecosystem and water quality research projects. For example, the imagery has been used to map seagrass beds and other habitats, and to trace annual changes in their size and location. A summary of this archive has been prepared that provides metadata on the date, time, and tide stage when each image was collected, the location and spatial extent that was photographed, and the resolution of the imagery.

Description:

Annual color infrared (CIR) aerial photographs acquired annually between 1997 and 2007 were used to classify distributions of intertidal and shallow subtidal native eelgrass Zostera marina and non-indigenous dwarf eelgrass Z. japonica in lower Yaquina estuary, Oregon. The use of digitally orthorectified aerial photography acquired at extreme low tides enabled very high resolution imagery from 15 to 25 centimeter ground pixels. The use of false-color infrared film enabled a high contrast between submerged aquatic vegetation (SAV) beds and bare substrate not visible in true color (RGB) film.

The initial success of this remote sensing method inspired similar efforts in nine Pacific Northwest (PNW) estuaries from Willapa Bay, WA to Humboldt Bay, CA (Fig. 1). Innovative techniques developed during the course of the project included a flight planning tool and a hybrid image classification methodology. The decadal study enabled the mapping of spatio-temporal patterns in the distribution of intertidal vegetation including an exponential expansion of the distribution of non-indigenous dwarf eelgrass Z. japonica in Yaquina Bay.

The methods developed in this study are applicable for use with four band digital aerial photography. Note* Diapotives of these imagery are housed at the EPA facility at Hatfield Marine Science Center, 2111 SE Marine science Drive, Newport, OR

URLs/Downloads:

Record Details: