A statistical assessment of carbon monoxide emissions from the Truman Shepherd coal fire, Floyd County, Kentucky

Abstract

Coal fires in eastern Kentucky are usually in abandoned mines. In many cases, the fires can be in close proximity to populated areas and can encroach upon the infrastructure. In addition, the gas emissions can be trapped in valleys at times of temperature inversions. The Truman Shepherd coal fire, Floyd County, Kentucky, is located in an abandoned mine adjacent to highway KY 80 and to the town of Howard. Building upon our previous studies of this fire from 2009 to 2012, in October 2013 we measured carbon monoxide emissions from a vent. Two methods of exponential smoothing and seasonal autoregressive integrated moving averages (SARIMA) were used to model CO emissions in the context of time series analysis. Due to the seasonality of the observations, the SARIMA model showed superior in both modeling and forecasting CO emissions with mean absolute percentage errors of 3.2% and 11.9%, respectively. Carbon monoxide emissions, on average, showed a gradual increase throughout the study period. Superimposed on the gradual CO increase is a daily sharp rise in CO, with the maximum peak exceeding 300ppm CO. The increase in CO starts between 10:00 and 11:00AM and generally peaks in the early afternoon, then declining until the next day's increase.