Influence of surface mining on seasonal hydrology response to storms across eastern Kentucky, USA

Abstract

ABSTRACT Mountain Top Removal and Valley Fill (MTR/VF) practices have drastically altered the surface cover, topography and hydrology of many watersheds across the Appalachian region of the US. These practices strip the bedrock from the ridges and peaks of watersheds, before removing the coal seams and depositing the waste fill into adjacent valleys. Existing research has generated conflicting outcomes as to the resulting hydrological impacts in response to storms. This creates potential issues for subsequent mitigation projects seeking to recreate prior hydrological conditions and riparian ecosystems. Our study focused on the potential influence of MTR/VF practices for a series of mined and unmined watersheds across the Eastern Coalfield of Kentucky. We analyzed rainfall-runoff response, focusing on how quickly rainfall was converted to quickflow and how much water left the catchment during storms for the 2022 water year. Lag times were shortened for the mined watersheds while quickflow coefficients reduced when vegetation cover increased. Valley fill-in mined watersheds also appears to create a delayed secondary release of quickflow from headwater locations during more extreme storms. These findings may assist future reclamation/mitigation practices for mined watersheds across Eastern Kentucky aiming to correctly recreate the hydrologic conditions that resemble those of unmined landscapes.