RAINa LIQ WTR REL BARE
Figure 18. GROFF2. For simplification, only the
DSa2
main elements of GROFF2 are shown. RI_2, RAINa,
~
RI 2
LIQ_WATER_ REL, and BARE control the amount of
snowmelt or rainfall that will enter depression stor-
STOR
age on the soil surface (STOR). STOR and DSa cal-
SURF2
culate the amount of water in depression storage on
the soil surface. SURF2 represents runoff. F repre-
F
sents infiltration of liquid water from depression
STOR EVAP
storage (STOR) into the top layer of soil (TP_LYR).
TP LYR
E represents seepage from the top soil layer
(TP_LYR) to a bottom soil layer (BTM_LYR). P rep-
E
TP LYR EVAP
resents percolation from BTM_LYR to subsurface
and groundwater storage (not shown). STOR_EVAP,
BTM LYR
TP_LYR_EVAP, and BTM_LYR_EVAP simulate wa-
ter evaporated from the soil surface, and the top and
BTM LYR EVAP
the bottom soil layers, respectively.
P
surface, the top layer of soil, and the bottom layer of soil (see Fig. 1). Only GROFF2 will be de-
scribed in this section because it is representative of all the other GROFF sectors. The objects in
GROFF2 are shown in Figure 18.
The name, brief description, initial condition, and units of each variable featured in GROFF2 are
listed in Table 9. BARE is set to zero because the watershed considered is completely snow covered.
TOP_LYR and BTM_LYR are the product of the adjusted initial moisture content and height of the
Table 9. Explanation of the variables in GROFF2.
Initial
Variable
Description
condition
Units
BARE
percent of ground not covered by snow
0
decimal
BTM LYR
water stored in bottom soil layer
99
mm
BTM LYR EVAP
evaporation rate from bottom soil horizon
0
mm/h
CSa
maximum seepage rate
0.42
mm/h
Ds
maximum percolation rate
0.35
mm/h
DSa2
adjusted depression storage depth
0
mm
E
seepage
0.25
mm/h
F
infiltration
0
mm/h
FP
infiltrability
6.63
mm/h
FP_2
rate of infiltration
0
mm/h
G_I
gravity-draining soil-water capacity for TP LYR
30
mm
G_II
gravity-draining soil-water capacity for BTM LYR
90
mm
IMCa
adjusted initial moisture content for top soil layer
0.48
vol/vol
KEFFa
adjusted effective hydraulic conductivity
0.13
mm/h
LIQ_WTR_REL
liquid water released from the snowpack
0
mm/h
MD_I
soilwater deficit for the top soil layer
0.12
mm
P
percolation
0.04
mm/h
RAINa
adjusted rainfall
0
mm/h
RI_2
rainfall/snowmelt input
0
mm/h
SA_I
available storage in top soil layer
12
mm
SA_II
available storage in bottom soil layer
81
mm
SAVa
adjusted average suction at the wetting front
200
mm
SURF2
surface runoff
0
mm/h
STOR
depression storage
0
mm
STOR_EVAP
evaporation rate from depression storage
0
mm/h
TINF
total amount of infiltrated water
0.48
mm
TP_LYR
water stored in top soil layer
48
mm
TP_LYR_EVAP
evaporation rate from top soil horizon
0
mm/h
Note: The variables in GROFF2 are similar to the variables in GROFF1, GROFF3, GROFF4, and
GROFF5; therefore, for simplification the variables from those sections will not be shown.
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