STREAM CHEMISTRY AND FOREST RECOVERY ASSESSMENT AND PREDICTION MODELLING IN COAL MINE AFFECTED WATERSHEDS

Kentucky is one of the largest coal producing states where surface coal mining has impacted natural land cover loss, soil loss, ecosystems services, and water quality. The Surface Mining Control and Reclamation Act (SMCRA) of 1977 was enacted to regulate active coal mines and restore abandoned mine lands; however, scientists have been debating whether regulations are sufficient to mitigate the coal mining effects on the environment. This study explored relationships between actively mined and reclaimed areas and conditions of vegetation change and water quality parameters. The study site covered 58 watersheds with Landsat derived variables of reclamation age, mining %, reclaimed forest %, and reclaimed woods %; as well as topographic variables such as elevation, slope, drainage density and infiltration. Water samples were collected to study changes in water quality variables (SO42-, alkalinity, conductivity, Ca2+, Mg2+, Mn2+, Al3+, and Fe2+,3+ ) in response to changes in land cover in spring (n=9), summer (n=14), and fall (n=58) in 2017. Pearson correlation analyses demonstrated conductivity has strong relationships with other coal mine-related water quality variables (except Al3+, Fe2+,3+, Mn2+ , elevation, slope, drainage density) and land cover variables. In addition, separate multivariate regression analyses were performed with fall conductivity values. First, conductivity response to mining %, reclamation age and topographic variables were examined (adjusted R2=0.818, p < 0.01). Second, vegetation cover change parameters were added to the same model, which yielded slightly improved R2 (adjusted R2 = 0.826, p < 0.01). Third, reclamation age and mining % were used to explain the quantity of reclaimed forested areas as a percentage of watersheds. The model was significant (p < 0.01) with adjusted R2 = 0.641 value. Results suggest that the quantity (area %) of reclaimed forests may be a predictor of mining % and reclamation age. This research revealed that conductivity is a predictable water quality that is highly associated with Coal Mine Related Stream Chemistry (CMRSC) where agriculture and urban areas are limited. Findings may help the scientific community and regulating agencies to improve their understanding of water quality attributes as well as refining land reclamation practices of coalfields.