Table 10. Tabular demonstration of conserva-
Table 11. Tabular demonstration of con-
tion of mass within STOR.
servation of mass within TP_LYR.
Hours
STOR
F
STOR EVAP
RI 2
SURF
Hours
TP_LYR
F
E
TP_LYR_EVAP
40
0
0
0
0
0
40
40.24
0
0.14
0
41
0
0
0
0
0
41
40.1
0
0.14
0
42
0
0
0
0
0
42
39.96
0
0.14
0
43
0
1.09
0
1.09
0
43
39.82
1.09
0.14
0
44
0
2.11
0
3.13
0
44
40.77
2.11
0.15
0
45
1.02
0.98
0
1.21
1.02
45
42.74
0.98
0.18
0
46
0.23
0.8
0
3.16
0.23
46
43.53
0.8
0.19
0
47
2.36
0.7
0
1.64
2.36
47
44.14
0.7
0.2
0
48
0.94
0.64
0
1.81
0.94
48
44.65
0.64
0.21
0
49
1.18
0.59
0
5.46
1.18
49
45.08
0.59
0.21
0
50
4.87
0.55
0
5.09
4.87
50
45.46
0.55
0.22
0
Figure 12. Tabular demonstration of conserva-
tion of mass within BTM_LYR.
Hours
BTM_LYR
E
P
BTM_LYR_EVAP
40
104.85
0.14
0.06
0
41
104.93
0.14
0.06
0
42
105.02
0.14
0.06
0
43
105.1
0.14
0.06
0
44
105.18
0.15
0.06
0
45
105.27
0.18
0.06
0
46
105.39
0.19
0.06
0
47
105.52
0.2
0.06
0
48
105.65
0.21
0.06
0
49
105.8
0.21
0.06
0
50
105.95
0.22
0.06
0
TECHNICAL DESCRIPTION OF SBS_STOR_&_FLOW_1
Subsurface and baseflow routing is included in the sectors called SBS_STOR_&_FLOW_1,
SBS_STOR_&_FLOW_2, GDWTR_&_BASFLW_1, and GDWTR_&_BASFLW_2 and is
accomplished using a single linear reservoir approach (Veissman et al 1977). In this approach, perco-
lation (P) from the bottom soil layer (BTM_LYR) is converted from mm/h to m3/s and then routed
through a fictitious reservoir. The outflow from the reservoir is lagged by a specified amount to
simulate the average time for a molecule of water to travel underneath the soil surface either as
subsurface or base flow. Therefore, because subsurface flow moves more quickly than baseflow,
subsurface flow is simulated by lagging the outflow from the linear reservoir by a relatively small
amount of time while base flow is simulated by lagging the outflow from the linear reservoir by a
relatively long amount of time. The name, brief description, initial condition, and units of each
variable featured in this section are listed in Table 13. For simplification, only
SBS_STOR_&_FLOW_1 will be described in this section because the overall structure of
SBS_STOR_&_FLOW_2, GDWTR_&_BASFLW_1, and GDWTR_&_BASFLW_2 is identical to
the overall structure of SBS_STOR_&_FLOW_1 .
The initial condition for DA was taken from page 5-13 of the GAWSER Manual. The initial
condition of KSSa is equivalent to KSS on page 5-6 of the GAWSER manual. QSS was also taken
from page 5-6 of the GAWSER manual. INFLOW_II is equal to I which is the product of P (from
GROFF2), DA, FATR, and PCT_2. OUTFLOW_II is equal to INIT_OUTFLOW. INIT_OUTFLOW is
the product of QSS, FATR, and PCT_2. SUBS_STOR is equal to INIT_SBS_STOR.
INIT_SBS_STOR is equal to the product of INIT_OUTFLOW and KSSa (Schroeter 1989).
Figure 20 shows SBS_STOR_&_FLOW_1 which contains the linear reservoir routing equations
used to route surbsurface flow. SBS_STOR is incremented by INFLOW_II and decremented by
30
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