Lecode is a new numerical approach for simulating geomorphic and stratigraphic processes that combines open-channel  flow with non-uniform sediment transport law, and semi-empirical diffusive mass wasting.

The model is designed to facilitate modelling of surface processes across multiple space and time scales, and under a variety of environmental and tectonic conditions.

A more detailed explanation of Lecode physics, algorithms and implementation is available in a paper from Salles & Duclaux (Geomorphology).

To start with, you may have a look at this Lecode Presentation which gives a 6 slide general overview of Lecode current capability.

The physics of open-channel flow is primarily based on an adapted Lagrangian formulation of shallow-water equations. The interaction between flow and surface geology is performed by a non-uniform total-load sediment transport law. Additional hillslope processes are simulated using a semi empirical methods based on a diffusion approach.
In Lecode, the resolution of flow dynamics is made on a triangulated grid automatically mapped and adaptively remeshed over a regular orthogonal stratigraphic mesh. These new methods reduce computational time while preserving stability and accuracy of the physical solutions.

Lecode models sediments compaction and the evolution of porosity and through time. The concept relies on the principle that both grain stress and pore pressure support the load of the overlying volume of rock. The model assumes that an increasing lithostatic pressure causes a decrease in porosity.

Mass wasting encompasses different processes such as landslide, debris flow or slump.

For mass wasting, Lecode considers a simplified approach that is not highly parameter dependant and that can provide first order mass wasting impacts at regional scale with minimum data requirements.
The method consists in:

assessing the region prone to mass wasting (conditional threshold),

estimating the volume of sediment based on mass wasting susceptibility map, and

propagating the sediment on the downslope areas using a diffusive approach.