Calibration and Evaluation of a Hydrologic Model for Loose-Dump Mine Spoil

Abstract

A hydrologic model was calibrated and evaluated for predicting water storage and transport in loose-dump mine spoil. Large columns were assembled in the laboratory to represent the four surface treatments of sieved spoil, topsoil + sieved spoil, topsoil only, and unamended spoil (control). A drainage outlet was placed at the bottom of each column and used to collect percolation through the columns. Rainfall was applied to the columns and simulated in the hydrologic model. Hydrologic parameters of saturated hydraulic conductivity, lambda, porosity and saturated water content were varied to calibrate the model to the observed data for all treatment groups. A separate rainfall sequence was used to evaluate the hydrologic response of the model. The calibrated parameters provided excellent predictions of water transport for all treatment groups. Water storage characteristics were increased by adding surface amendments to the control in all cases primarily because of the addition of microporosity to the system.