Difference between revisions of "Lateral MWT"

From Gsshawiki
Jump to: navigation, search
Line 5: Line 5:
 
|  
 
|  
 
:  
 
:  
| width=550 | ''c = theta * alpha * K<sub>w</sub> / phi || (1)
+
| width=550 | ''c = θ * α * K<sub>w</sub> / Φ || (1)
 
|}
 
|}
 
{| |- | : | width=550  
 
{| |- | : | width=550  
Line 11: Line 11:
 
|}
 
|}
 
{| |- | : | width=550  
 
{| |- | : | width=550  
|''theta = lateral slope (deg)
+
|''θ = lateral slope (deg)
 
|}
 
|}
 
{| |- | : | width=550  
 
{| |- | : | width=550  
|''alpha = hydraulic properties of water, constant (p*g/mu ~54.7x10<sup>-6</sup> m<sup>-1</sup> s<sup>-1</sup>)
+
|''α = hydraulic properties of water, constant (ρ*g/μ ~54.7x10<sup>-6</sup> m<sup>-1</sup> s<sup>-1</sup>)
 
|}
 
|}
 
{| |- | : | width=550  
 
{| |- | : | width=550  
Line 20: Line 20:
 
|}
 
|}
 
{| |- | : | width=550  
 
{| |- | : | width=550  
|''phi = effective porosity (unitless)
+
|''Φ = effective porosity (unitless)
 
|}
 
|}

Revision as of 21:40, 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) below 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)