ConcentrationTracker: Landlab components for tracking material concentrations in sediment

Abstract. We present a set of new Landlab numerical model components that allow users to track sediment properties across a landscape grid. The components use a mass-balance approach to partition the mass concentration of each property based on sediment fluxes calculated by various Landlab flux components. The methods are generic, allowing the user to assign any sediment property that can be expressed as a mass, volume, or number concentration (for example, mass of magnetite, volume of quartz, number of zircons, number of radiogenic 10Be atoms, "equivalent dose" of luminescence). Several properties can be tracked at once, each with concentration tracked in both sediment and bedrock at every location on the grid. Two ConcentrationTracker components have been formulated; one for distributed, space- and time-varying hillslope regolith movement and another for transport in fluvial networks, allowing for interaction between sediment in the water column and on the channel bed. These components can be used individually to study a single process or coupled to study the interactions of multiple processes acting on a dynamic landscape. We present two examples that illustrate the diverse uses of the ConcentrationTracker components: colour banding in hillslope regolith and provenance tracking of fluvial sediments.