Summary
This technical report discusses the behavior of lysimeters in measuring net percolation of water through unsaturated soil systems. It outlines the significance of lysimeter design in accurately capturing drainage processes, particularly in infrastructure applications such as waste rock dumps and tailings ponds. The report presents a case study from the Kidston Gold Mine in North Queensland, Australia, where lysimeters were installed to monitor moisture conditions and percolation rates. The study highlights the challenges faced due to elevated water tables within lysimeters, which can lead to unrealistic infiltration rates. Numerical modeling was employed to optimize lysimeter design variables, including wall height and hydraulic conductivity. The report details various simulations and analyses conducted to assess the performance of shallow and deep lysimeter pans under different hydraulic conditions. It concludes that increasing the wall height of the lysimeter can enhance performance under low percolation rates, ensuring accurate measurement of net percolation.
