LEACHM (Leaching Estimation and Chemistry Model) is a public-domain, unsaturated zone numerical model simulator (Hutson, 2003). LEACHM is a widely used unsaturated zone simulator (e.g., Sogbedji et al., 2001a; Asada et al., 2013) that has been extensively benchmarked against similar codes such as HYDRUS (e.g., Nolan et al., 2005; Sarmah et al., 2006; Ogorzalek et al., 2008). It is a …