~ ~ ~ PURPOSE ~ ~ ~
this subroutine computes maximum surface depressional storage depth based on
random and oriented roughness and slope steepness
~ ~ ~ INCOMING VARIABLES ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
iop(:,:,:) |julian date |date of tillage operation
mgt_op |none |operation code number
ranrns_hru(:)|mm |random roughness for a given HRU
sol_ori(:) |mm |oriented roughness (ridges) at time of a given tillage operation
usle_ei |100(ft-tn in)/(acre-hr)|USLE rainfall erosion index
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ OUTGOING VARIABLES ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
stmaxd(:) |mm |maximum surface depressional storage for day in a given HRU
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ LOCAL DEFINITIONS ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
cumei(:) |Mj*mm/ha*hr |cumulative USLE rainfall erosion index since last
|tillage operation
cumrt(:) |mm H2O |cumulative rainfall since last tillage operation
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ SUBROUTINES/FUNCTIONS CALLED ~ ~ ~
Intrinsic:exp
SWAT:eiusle
~ ~ ~ ~ ~ ~ END SPECIFICATIONS ~ ~ ~ ~ ~ ~
Calculate current cummulative erosivity and rainfall Calculate the decay factor df based on %clay and %organic matter or %organic carbon Determine the current random and oriented roughness using cumei and cumrt and initial random and oriented roughness values
Compute the current maximum depressional storage using percent slope steepness and current random and oriented roughness values determined above