Compartment Graphs and Linear Systems - Environmental Modeling - page 316

Evapotranspiration Precipitation

Interception
storage

Unsaturated
soil moisture
storage

Surface water
storage

Saturated
groundwater

Runoff

Compartment Fluxes across outer borders

Fluxes between environmental compartments

Fig. 18.1 Network of compartments for modeling the terrestrial part of the hydrological cycle
according to Freeze and Cherry ( 1979 ), modified by E.H.

Table 18.1 Tabular representation of connections within the compartment system of Fig. 18.1
Storage

Interception Soil moisture Ground-water Surface water

Interception x

Soil moisture x x

Groundwater x

Surface water

0
@

1
A

0001
0011
0001
0000

A ¼

(18.1)

which is directly related to the tabular representation of Table 18.1 .
A more complex representation of the terrestrial part of the hydrological cycle is
given in Fig. 18.2 . Vegetation and surface are included as new compartments,
interception is omitted. Several processes, which were neglected for simplicity in
Fig. 18.1 , are included. For example, due to capillary rise there may be fluxes from
groundwater to the soil and from soil to the surface. Instead of surface water the less
general term 'channel storage' is preferred in this graph.
The adjacency matrix for the system of Fig. 18.2 is: