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NOAA Seminar Series: Remote sensing of anthropogenic debris in stream channelsFree
Title: Remote sensing of anthropogenic debris in stream channels
Speaker: Elena Aguilar, NOAA EPP/MSI CESSRST-II Fellow at SDSU
Date: August 22, 20223
Time: 1:30 PM ET
Meeting Link : meet.google.com/ead-ypxo-gvb
PIN: 651 945 406#
Inadequate management of anthropogenic waste is a challenge for coastal waters in the US-Mexico border region. Managing waste requires detecting and monitoring locations where uncontrolled disposal and debris accumulation occurs at high rates. Watershed-scale remote sensing can aid the understanding of the distribution, pools, and fluxes of plastic materials in pluvial systems. The Los Laureles Canyon watershed (LLCW), located in Tijuana, Mexico, is a large source of plastic pollution for the Tijuana River Estuary in Imperial Beach, California. Through a combination of field, laboratory, and remote sensing methods, we identified surficial plastic materials and waste hotspots in LLCW and 6 visually assessed the utility of spectral mixture models and WorldView-3 (WV3) shortwave infrared (SWIR) broadband imagery for plastic mapping. Field trash surveys conducted in LLCW reveal channel reaches have large scale waste patches (4-10m²) as a result of dumping. Laboratory reflectance spectroscopy was used to characterize the diversity of plastic reflectance and assess spectral signatures to inform multispectral image analysis. Samples processed to date show plastics have consistent absorptions at about 1210 nm, 1410 nm, 1660-1730nm, and 2100-2300nm wavelengths, depending on the polymer type. When convolved to the spectral response function of the WV3 sensor, mean plastic reflectance retains prominent features between 1660-1730 nm and above 2200 nm wavelengths, similar to an image endmember observed through principal components analysis of LLCW imagery. A spectral mixture model uses the matched filtering algorithm and selected image endmember to map built-environment plastic infrastructure and waste hotspots in areas explored during field visits.