ero_ovrsed Subroutine

subroutine ero_ovrsed()

Uses

  • proc~~ero_ovrsed~~UsesGraph proc~ero_ovrsed ero_ovrsed module~basin_module basin_module proc~ero_ovrsed->module~basin_module module~climate_module climate_module proc~ero_ovrsed->module~climate_module module~hru_module hru_module proc~ero_ovrsed->module~hru_module module~hydrograph_module hydrograph_module proc~ero_ovrsed->module~hydrograph_module module~organic_mineral_mass_module organic_mineral_mass_module proc~ero_ovrsed->module~organic_mineral_mass_module module~plant_module plant_module proc~ero_ovrsed->module~plant_module module~soil_module soil_module proc~ero_ovrsed->module~soil_module module~time_module time_module proc~ero_ovrsed->module~time_module module~urban_data_module urban_data_module proc~ero_ovrsed->module~urban_data_module module~hydrograph_module->module~basin_module module~hydrograph_module->module~time_module 
~ ~ ~ PURPOSE ~ ~ ~
this subroutine computes splash erosion by raindrop impact and flow erosion by overland flow

~ ~ ~ INCOMING VARIABLES ~ ~ ~
name        |units         |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
hhqday(:)   |mm H2O        |surface runoff generated each timestep 
                           |of day in HRU
hru_km(:)   |km2           |area of HRU in square kilometers
rwst(:)%weat%ts(:)  |mm H2O        |precipitation for the time step during the
                           |day in HRU
eros_spl      |none          |coefficient of splash erosion varing 0.9-3.1
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ OUTGOING VARIABLES ~ ~ ~
name        |units         |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
hhsedy(:,:)|tons           |sediment yield from HRU drung a time step
                           |applied to HRU

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ LOCAL DEFINITIONS ~ ~ ~
name        |units         |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
jj          |none          |HRU number
kk          |none          |time step of the day
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ SUBROUTINES/FUNCTIONS CALLED ~ ~ ~
Intrinsic: log10, Exp, Real

~ ~ ~ ~ ~ ~ END SPECIFICATIONS ~ ~ ~ ~ ~ ~

Splash erosion model is adopted from EUROSEM model developed by Morgan (2001). Rill/interill erosion model is adoped from Modified ANSWERS model by Park et al.(1982) Code developed by J. Jeong and N. Kannan, BRC.

Fraction of sand Soil detachability values adopted from EUROSEM User Guide (Table 1) canopy cover based on leaf area index canopy cover is assumed to be 100% if LAI>=1 Rainfall kinetic energy generated by direct throughfall (J/m^2/mm) Rainfall kinetic energy generated by leaf drainage (J/m^2) Depth of rainfall total kinetic energy by rainfall (J/m^2) total soil detachment by raindrop impact Impervious area of HRU maximum water depth that allows splash erosion Overland flow erosion cover and management factor used in usle equation (ysed.f) specific weight of water at 5 centigrate =9807N/m3 Impervious area of HRU

Arguments

None