title: Drainage model
text: # Drainage model
  
  Drainage model may refer to:
  
  * a surface drainage model or rainfall-runoff model; see surface runoff, runoff model (reservoir)
  * a subsurface (groundwater), drainage model related to:
     * a spacing equation for subsurface pipe drains and open ditches (horizontal drainage) or wells (vertical drainage); see watertable control
     * a hydrological subsurface drainage model; see soil salinity control for an example of an agro-hydro-salinity subsurface drainage model (SaltMod)
     * groundwater flow in the aquifer; see groundwater model or an example of an agro-hydro-salinity groundwater model: SahysMod
  