Vadose zone and soil cover analysis

VADOSE/W analyzes the interaction between the soil profile , vegetation, and atmosphere using a sophisticated land-climate interaction boundary condition. It is able to simulate a range of scenarios, from simple infiltration due to rainfall, to complex modeling of snow melt, root transpiration and surface evaporation, runoff and ponding.


VADOSE/W can be applied to the analysis and design of land reclamation, mine closure, and waste containment projects.



Key Features

Input Climate Data

VADOSE/W provides a climate boundary condition with the ability to simulate surface vegetation and measured climate data including surface temperature, relative humidity, wind speed, precipitation, and potential evaporation/transpiration.


Model Evaporation

The relative humidity of a soil can be determined when the soil temperature and water pressure are simultaneously solved and vapour flow within the soil is modeled. VADOSE/W meets these requirements, and is fully coupled in two dimensions.

Powerful Graphing

Users can plot critical information such as precipitation and infiltration, snow accumulation and melt, plant transpiration, ground freezing and thawing, potential and actual evaporation, surface seepage, surface runoff and ponding, and groundwater recharge.


Root Water Uptake

VADOSE/W offers the capability of modeling root water uptake, with consideration of partitioning between actual evaporation and transpiration, plant stress factors, and root distribution.

VADOSE/W can model a comprehensive range of stability problems

Download GeoStudio to view GSZ files

Simulating Soil Evaporation with Lab Verification

This illustration shows how VADOSE/W can model actual evaporation from soil. This is a verification example in that the results are compared with a lab experiment. VADOSE/W is unique in that actual evaporation from a ground surface is based on the stress state in the soil; in particular the temperature and relative humidity and matric suction at the soil–climate interface.


Water and Oxygen Flow through a Soil Cover

This example illustrates the basic methodology for simulating soil-climate interaction of an engineered soil cover system placed over a waste material. The primary objective of the simulation is to assess the inflow of water and oxygen through the base of the cover into the waste. This tutorial also demonstrates the various aspects involved in VADOSE/W models.


VADOSE/W's intuitive modeling workflow

Create a VADOSE/W analysis and set up the problem workspace. Choose analysis type, including steady-state or transient analyses, and define initial pore-water pressure conditions, temperature conditions, gas diffusion properties (if applicable), convergence criteria, time duration and increments, and more.

Draw the regions in your domain using CAD-like drawing tools, including drawing polygon and circular regions, coordinate import, copy-paste geometric items, length and angle feedback, region splitting and merging, and direct keyboard entry of coordinates, lengths, and angles. Alternatively, import AutoCAD DWG or DXF files directly into GeoStudio to create your domain geometry.

Define the material properties for your analysis, assign them to regions on the domain, and then define your initial pore-water pressure and temperature conditions. Select from Simplified Thermal, Full Thermal and Interface material models. Define hydraulic material functions using spline data point entry, Fredlund-Xing or van Genuchten methods and define thermal constants or functions. Define the initial pore-water pressure and temperature conditions for transient scenarios using results from other SEEP/W, TEMP/W or VADOSE/W analyses, defined spatial functions or draw an initial water table.

Define hydraulic boundary conditions to simulate total head, pressure head, pore-water pressure, unit flux (q) or total flux (Q) conditions. Define thermal boundary conditions, including temperature, thermal flux, and thermal total flux. Define climate boundary conditions by inputting climate data sets (including precipitation, air temperature, and relative humidity measurements), and vegetation functions. Define gas boundary conditions, such as concentration, unit flux and total flux, if applicable. Time-varying conditions can also be modeled.

Open Draw Mesh Properties to refine the mesh drawn on the entire domain, or along specific geometric regions, lines or boundaries. Interface elements can also be created to simulate geosynthetic or other thin materials. Add surface layers to the ground surface where climate boundary conditions are required.

When your problem is completely defined, start the analysis process in the Solve Manager window. The Solve Manager displays the solution progress, allowing you to cancel if necessary. While the solution is in progress, you can look at preliminary results in the Results window.

When the Solver is finished, the Total Head contours are displayed, along with the location of the phreatic surface, or zero-pressure isoline, and velocity vectors. You can display other contours of almost any parameter including pore-water pressure, material properties, water flow, and gradients, using the Draw Contours window. Contour legends and properties can also be modified. Labels can be added to contour lines and flux sections for display in Results View.

Interactively select any node or gauss region to view result information, including total head, pore-water pressure, material properties, and more. Display plots of computed results over the x- or y-direction or create time-varying plots of results in transient analyses, such as total head, water flux, cumulative water volume, and more. Water balance and climate graphs can also be created, such as evaporation, cumulative infiltration, transpiration, and sublimation. Generate reports of the definition and results, and export into other applications such as Microsoft Excel for further analysis.

The power of integration

VADOSE/W offers simple but powerful analytical capabilities when used in combination with other GeoStudio products.


VADOSE/W results in SLOPE/W

Using VADOSE/W computed pore-water pressures in SLOPE/W makes it possible to model the effects of climate-controlled, net infiltration on stability.

VADOSE/W results in CTRAN/W

Water velocities computed by a VADOSE/W land-climate interaction analysis can be used in CTRAN/W to study the transport of contaminants. For example, you could model the movement of salts into a reclamation cover overlying saline-sodic overburden waste.