Abstract:
During the last several decades, the study of the movement of water in the unsaturated zone has become an issue of great significance due to profound effects of the physical and chemical processes occurring in this zone on the quality of both surface and subsurface waters. It is generally known that the precipitation, pressure and evaporation are the dominant controls on the movement of water into surface and ground waters. In this study, a general methodology has been developed to evaluate the effect of soil water hysteresis, and temporal variability in precipitation and evaporation input data on the movement of water in soils.
This report documents version 4.16.0110 of HYDRUS-1D, a software package for simulating water movement in one-dimensional variably saturated media. The software consists of the HYDRUS computer program, and the HYDRUS 1 D interactive graphics-based user interface. The HYDRUS program numerically solves the Richards' equation for variably saturated water flow. The flow equation incorporates a sink term to account for water uptake by plant roots. The program may be used to analyze water and solute movement in unsaturated, partially saturated, or fully saturated porous media. The flow region may be composed of no uniform soils. Flow and transport can occur in the vertical, horizontal, or a generally inclined direction. The water flow part of the model can deal with prescribed head and flux boundaries, boundaries controlled by atmospheric conditions, as well as free drainage boundary conditions. The governing flow and transport equations are solved numerically using Galerkin-type linear finite element schemes.
The present study aims to study the movement of water in the unsaturated zone. A one-dimensional unsaturated transport model was used to simulate the movement of water in the vadose zone. Simulations were conducted in HYDRUS-1D code using measured precipitation data for the period January 1st-2015 to March 3 I '-2016.
