**3.5. Available vadose zone models**

A large number of programs are available for the description of water flow and solute transport in soil vadose zone. Below is the list and brief description of the most widely used software for modelling water flow and solute transport, which are applicable to unsaturated and partially saturated conditions.

HYDRUS‐1D software includes one‐dimensional finite‐element model for simulating the movement of water, heat, and multiple solutes in variably saturated media [37].

HYDRUS (2D/3D) is a software package for simulating water, heat, and solute movement in two‐ and three‐dimensional variably saturated media [38].

MACRO is a one‐dimensional, process‐oriented, dual‐permeability model for water flow and reactive solute transport in soil [30].

TOUGH ('transport of unsaturated groundwater and heat') suite of software codes are multidimensional numerical models for simulating the coupled transport of water, vapour, non‐condensable gas, and heat in porous and fractured media [39].

SWAP (soil, water, atmosphere, and plant) simulates transport of water, solutes and heat in unsaturated/saturated soils at field scale level, during growing seasons and for long‐term time series [40].

The RZWQM is an integrated physical, biological, and chemical process model that simulates plant growth and movement of water, nutrients, and pesticides in run‐off and percolate within agricultural management systems [41].

Animo is a detailed process‐oriented simulation model for the evaluation of nitrate leaching to groundwater, N and P loads on surface waters and greenhouse gas emission [42].

LEACHM (the leaching estimation and chemistry model) refers to a suite of simulation models describing the water and chemical regime in unsaturated or partially saturated soil profiles [43].

Daisy is a dynamic model for the simulation of water and nitrogen dynamics and crop growth in agro‐ecosystems [44].
