"Water and Agrochemicals in the soil, crop and Vadose Environment"

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1 Presentation

The WAVE model (Water and Agrochemicals in the soil, crop and Vadose Environment) describes the transport and transformations of matter and energy in the soil, crop and vadose environment.

The WAVE model has been developed at the Institute for Land and Water Management of the Katholieke Universiteit Leuven (Belgium).

It's a deterministic, numerical and integrated model that simulates the behavior of water, heat and agrochemicals in the vertical direction. The WAVE model is an integration of earlier models such as SWATRER (water module), SOILN (nitrogen module), LEACHN (heat and solute modules) and SUCROS (crop growth module).

The WAVE model is written in FORTRAN and can be run either under UNIX or MS-DOS.

2 Space and time scales

WAVE describes mass and energy fluxes according to the vertical direction. The soil profile is composed of soil layers which are subdivided into equally spaced intervals ( the compartments). At each node of the compartments, the state variables are calculated using finite difference techniques.

A time step smaller than a day is used to calculate the different state variables and can be adjusted according to the desired accuracy.

3 The WATER transport module

The water transport module is based on Richards equation.

The moisture retention and the hydraulic conductivity functions must be specified by means of parametric hysteresis or non-hysteresis models (Van Genuchten, Gardner, Brooks and Corey...). Upper and lower boundary conditions must also be specified and several options are proposed so that the water flow equation can be solved for different geo-hydrological conditions.

4 The SOLUTE transport module

The solute transport module relies on a two region convection dispersion concept. So, it assumes the existence of both mobile and immobile soil water regions.

The upper boundary condition is a flux type boundary condition whereas a zero concentration gradient is assumed at the bottom.

5 The HEAT transport module

The heat transport module uses the 1D heat flow equation.

The upper boundary condition considers that the temperature at the soil surface depends on the daily solar radiation. On the other hand, the lower boundary condition is defined as a constant soil temperature (~7°c).

6 The CROP GROWTH module

The SUCROS model (simple universal and comprehensive crop growth model) is included in the WAVE model and linked to the other modules. This model was developed at the Center for Agro-biological Research (CABO), Wageningen, The Netherlands. It calculates the crop development rate as a function of a set of climatic and plant phenologic parameters.

Crop parameters for winter weat, spring weat, maize, potato and sugar beet are available in the WAVE 2.1 version.

7 The NITROGEN module

This module is adapted from the SWATNIT model. It describes the transformation processes for the organic and inorganic nitrogen present in the soil. The plant nitrogen uptake is modeled by a sink term added to the transport equation. Potential transformation rates are function of the soil moisture and temperature.

8 Siehe auch

9 Weblinks

Kategorien: Modelle

Letzte Änderung dieses Artikels: December 19, 2011, at 09:34 AM