Difference between revisions of "Lateral MWT"

From Gsshawiki
Jump to: navigation, search
(Created page with "Once melt-water flows vertically through the pack using the VMWT algorithms it reaches the saturated area above the ground and below the snow pack. This melt-water moves lateral...")
 
 
(7 intermediate revisions by the same user not shown)
Line 1: Line 1:
Once melt-water flows vertically through the pack using the VMWT algorithms it reaches the saturated area above the ground and below the snow pack.  This melt-water moves laterally along the ground through a saturated Darcian flow.  GSSHA currently uses methods developed by Colbeck (1974) to determine the flux volumes between each cell.  The equation and figure from Colbeck (1974) below show how the flux rate is calculated for lateral flow.
+
Once melt-water flows vertically through the pack ('''[[Vertical MWT]]''') it reaches the saturated area above the ground and below the snow pack.  This melt-water moves laterally along the ground through a saturated Darcian flow.  GSSHA currently uses methods developed by Colbeck (1974) to determine the flux volumes between each cell.  The equation and figure - from Colbeck (1974) - show how the flux rate is calculated for lateral flow.
 +
 
 +
{|
 +
|-
 +
|
 +
:
 +
| width=550 | ''c = θ * α * K<sub>w</sub> / Φ || (1)
 +
|}
 +
{| |- | : | width=550
 +
|''c = lateral flux rate (m<sup>2</sup>/hr)
 +
|}
 +
{| |- | : | width=550
 +
|''θ = lateral slope (deg)
 +
|}
 +
{| |- | : | width=550
 +
|''α = hydraulic properties of water, constant (ρ*g/μ ~54.7x10<sup>-6</sup> m<sup>-1</sup> s<sup>-1</sup>)
 +
|}
 +
{| |- | : | width=550
 +
|''K<sub>w</sub> = saturated hydraulic conductivity of snow (~0.00555 m s<sup>-1</sup>)
 +
|}
 +
{| |- | : | width=550
 +
|''Φ = effective porosity (unitless)
 +
|}
 +
 
 +
[[File:Colbeck_1974_Picture.jpg]]

Latest revision as of 21:50, 27 November 2012

Once melt-water flows vertically through the pack (Vertical MWT) it reaches the saturated area above the ground and below the snow pack. This melt-water moves laterally along the ground through a saturated Darcian flow. GSSHA currently uses methods developed by Colbeck (1974) to determine the flux volumes between each cell. The equation and figure - from Colbeck (1974) - show how the flux rate is calculated for lateral flow.

c = θ * α * Kw / Φ (1)
c = lateral flux rate (m2/hr)
θ = lateral slope (deg)
α = hydraulic properties of water, constant (ρ*g/μ ~54.7x10-6 m-1 s-1)
Kw = saturated hydraulic conductivity of snow (~0.00555 m s-1)
Φ = effective porosity (unitless)

Colbeck 1974 Picture.jpg