Reflective spectra of gasoline, diesel, and jet fuel A on sand substrates under ambient and cold conditions: Implications for detection using hyperspectral remote sensing and development of age estimation models

Fuel spills are a very common occurrence globally and the traditional methods of identification and remediation can be expensive, hazardous, and time consuming. Hyperspectral remote sensing is a technology that utilizes images from a variety of air vehicles or satellites where each pixel in the image contains a quantitative reflected light spectrum that is a function of the materials in view. Laboratory and field experiments are desirable for building an effective reflective spectra library. This project evaluated the reflective spectra of gasoline, diesel, and jet fuel A on the spectrally bright Ottawa sand and a darker silica-rich sand from New Mexico (New Mexico 15) under room temperature and cold weather conditions. For the room temperature experiments, gasoline was only detectable to 90 min after initial application, diesel fuel was detectable out to 11 weeks on Ottawa sand, as well as the New Mexico 15 samples. Jet fuel A was detectable out to 5 weeks on Ottawa sand and the New Mexico 15 samples. For all cold condition experiments, gasoline was identifiable on substrates up until the 72-h mark largely and diesel fuel and jet fuel A were identifiable on each substrate out to 5 weeks. Regressions were fit to vaporization curves for room temperature and cold weather conditions and all were logarithmic in nature except for jet fuel A under lab and cold weather conditions which were best fit by power functions. Unexpectedly, diesel fuel evaporated more under cold weather conditions. Results indicate that fuel-substrate experiments can provide critical data for hyperspectral remote sensing investigations and future detailed work on fuels and other organic compounds is warranted.