Finite water-content vadose zone flow method (original) (raw)
The finite water-content vadose zone flux method represents a one-dimensional alternative to the numerical solution of Richards' equation for simulating the movement of water in unsaturated soils. The finite water-content method solves the advection-like term of the Soil Moisture Velocity Equation, which is an ordinary differential equation alternative to the Richards partial differential equation. The Richards equation is difficult to approximate in general because it does not have a closed-form analytical solution except in a few cases. The finite water-content method, is perhaps the first generic replacement for the numerical solution of the Richards' equation. The finite water-content solution has several advantages over the Richards equation solution. First, as an ordinary differentia
| Property | Value |
|---|---|
| dbo:abstract | The finite water-content vadose zone flux method represents a one-dimensional alternative to the numerical solution of Richards' equation for simulating the movement of water in unsaturated soils. The finite water-content method solves the advection-like term of the Soil Moisture Velocity Equation, which is an ordinary differential equation alternative to the Richards partial differential equation. The Richards equation is difficult to approximate in general because it does not have a closed-form analytical solution except in a few cases. The finite water-content method, is perhaps the first generic replacement for the numerical solution of the Richards' equation. The finite water-content solution has several advantages over the Richards equation solution. First, as an ordinary differential equation it is explicit, guaranteed to converge and computationally inexpensive to solve. Second, using a finite volume solution methodology it is guaranteed to conserve mass. The finite water content method readily simulates sharp wetting fronts, something that the Richards solution struggles with. The main limiting assumption required to use the finite water-content method is that the soil be homogeneous in layers. The finite water-content vadose zone flux method is derived from the same starting point as the derivation of Richards' equation. However, the derivation employs a hodograph transformation to produce an advection solution that does not include soil water diffusivity, wherein becomes the dependent variable and becomes an independent variable: where: is the unsaturated hydraulic conductivity [L Tâ1], is the capillary pressure head [L] (negative for unsaturated soil), is the vertical coordinate [L] (positive downward), is the water content, (â) and is time [T]. This equation was converted into a set of three ordinary differential equations (ODEs) using the Method of Lines to convert the partial derivatives on the right-hand side of the equation into appropriate finite difference forms. These three ODEs represent the dynamics of infiltrating water, falling slugs, and capillary groundwater, respectively. (en) |
| dbo:thumbnail | wiki-commons:Special:FilePath/Fwc_domain.png?width=300 |
| dbo:wikiPageID | 46591747 (xsd:integer) |
| dbo:wikiPageLength | 13028 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1102153072 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Method_of_lines dbr:Infiltration_(hydrology) dbc:Hydrology dbr:Closed-form_expression dbr:Time dbr:File:Falling_slugs.png dbr:File:Fwc_domain.png dbr:File:Groundwater_fronts.png dbr:File:Inf_fronts.png dbr:Finite_difference dbr:Partial_differential_equation dbr:Hydraulic_conductivity dbr:Soil_Moisture_Velocity_Equation dbc:Ordinary_differential_equations dbc:Partial_differential_equations dbc:Soil_physics dbr:Ordinary_differential_equation dbr:Ordinary_differential_equations dbr:Pressure_head dbr:Water_retention_curve dbr:Vadose_zone dbr:Partial_derivatives dbr:Water_content dbr:Richards_equation dbr:Hodograph_transformation dbr:Richards'_equation dbr:Finite_volume |
| dbp:wikiPageUsesTemplate | dbt:Reflist |
| dct:subject | dbc:Hydrology dbc:Ordinary_differential_equations dbc:Partial_differential_equations dbc:Soil_physics |
| rdfs:comment | The finite water-content vadose zone flux method represents a one-dimensional alternative to the numerical solution of Richards' equation for simulating the movement of water in unsaturated soils. The finite water-content method solves the advection-like term of the Soil Moisture Velocity Equation, which is an ordinary differential equation alternative to the Richards partial differential equation. The Richards equation is difficult to approximate in general because it does not have a closed-form analytical solution except in a few cases. The finite water-content method, is perhaps the first generic replacement for the numerical solution of the Richards' equation. The finite water-content solution has several advantages over the Richards equation solution. First, as an ordinary differentia (en) |
| rdfs:label | Finite water-content vadose zone flow method (en) |
| owl:sameAs | freebase:Finite water-content vadose zone flow method yago-res:Finite water-content vadose zone flow method wikidata:Finite water-content vadose zone flow method https://global.dbpedia.org/id/2EUet |
| prov:wasDerivedFrom | wikipedia-en:Finite_water-content_vadose_zone_flow_method?oldid=1102153072&ns=0 |
| foaf:depiction | wiki-commons:Special:FilePath/Falling_slugs.png wiki-commons:Special:FilePath/Fwc_domain.png wiki-commons:Special:FilePath/Groundwater_fronts.png wiki-commons:Special:FilePath/Inf_fronts.png |
| foaf:isPrimaryTopicOf | wikipedia-en:Finite_water-content_vadose_zone_flow_method |
| is dbo:wikiPageRedirects of | dbr:Finite_water-content_method |
| is dbo:wikiPageWikiLink of | dbr:Infiltration_(hydrology) dbr:Finite_water-content_method dbr:Soil_moisture dbr:Soil_moisture_velocity_equation dbr:Richards_equation |
| is foaf:primaryTopic of | wikipedia-en:Finite_water-content_vadose_zone_flow_method |
