Site Characterization of the White Oak Creek - Melton Valley Watershed
An environmental site characterization of the White Oak Creek - Melton Valley watershed on the Oak Ridge Reservation was conducted using various remote sensing datasets, including natural color, color infrared and historical black and white photography, multispectral and thermal imagery, gamma radiation measurements, and geophysical magnetic and electromagnetic measurements acquired by airborne remote sensing surveys. The fusion of disparate datasets and the interrelationships of these datasets were used to address several major contamination themes involving the study area. While not taking the place of ground-based surveys or environmental sampling, combined remote sensing methods provide a fast, economical way to delineate the locations of known disposal areas, confirm the location of undocumented disposal sites, locate the major concentrations of buried waste, and aid in environmental sampling planning.
Historical
aerial photography provided an overview of the overall sequence of
events, such as at Waste Area Grouping (WAG) 5 where the chronology developed
from the historical photographs recorded the overall sequence of waste
disposal activities.
Man-made
gamma radiation levels at WAG 5, significantly above background, agreed
with known boundaries of waste disposal areas where radioactive wastes
were buried. Because metallic objects are frequently buried along with
other wastes, the vertical magnetic gradient geophysical data (not shown)
was used to delineate the boundaries of major burial grounds such as WAG
5 and to identify magnetic anomalies located away from known burial grounds.
Ground based magnetic survey data enhanced resolution enough to determine,
in some instances, individual trench boundaries.
Daytime
multispectral imagery showed evidence of thermal patterns that appeared
to correspond to waste disposal trench locations and, along with natural
color and color infrared photography, exhibited vegetative striations that
also correlated with waste trenches.
Although
predawn
thermal datasets were not helpful in defining trenches, they proved
very effective in both identifying the surface water mixing process of
White Oak Creek and the Clinch River and in refining surface hydrology.