Utilities

BASIN DAILY WATER BALANCE FUNCTION

PASTE THE COMMANDS BELOW IN R TO CREATE THE WATER BALANCE FUNCTION

watbal = function(rb) {

rb$watbal.tmp=with(rb,precip-streamflow-trans-evap)

rb$sd=with(rb,sat_def-rz_storage-unsat_stor)

tmp=diff(rb$sd)

tmp=c(0,tmp)

rb$sddiff=tmp

tmp=diff(rb$snow)

tmp=c(0,tmp)

rb$snodiff=tmp

tmp=diff(rb$detention_store)

tmp=c(0,tmp)

rb$detdiff=tmp

tmp=diff(rb$litter_store)

tmp=c(0,tmp)

rb$litdiff=tmp

tmp=diff(rb$canopy_store)

tmp=c(0,tmp)

rb$candiff=tmp

tmp=diff(rb$gw.storage)

tmp=c(0,tmp)

rb$gwdiff=tmp

rb$watbal=with(rb,watbal.tmp+sddiff-snodiff-detdiff-litdiff-candiff-gwdiff)

rb

}

To use this function in an R data set:

If your basin daily output is called (for example) "bd" type "bd=watbal(bd)".

This will add a number of fields to your basin daily output file, the last of which will be called "watbal". This is your water balance error. You should see a minor numerical error here even if your water balances (on the order of 10^-6). If your watbal values are negative then water inputs are less than water outputs, and vice versa.