Information Technology Reference
In-Depth Information
o
Q
r
is the “run up” height (depends on the potential energy and expresses the
height that can be overcome by the debris flow)
o
Q
d
is the
maximum depth of detrital cover, that can be transformed by
erosion in landslide debris (it depends on the type of detrital cover)
o
Q
o
is the debris outflow from central cell to adjacent cell (six components)
o
Q
i
is the debris inflow from adjacent cell to central cell (six components)
The elements of
Q
a
express the value of the altitude; also the elements of
Q
r
are
expressed as a length; the elements of
Q
th
and
Q
d
represent the material quantity
inside the cell, expressed as thickness/depth; then
Q
o
and
Q
i
are expressed in terms
of length by homogeneity.
•
P
is the set of the global physical and empirical parameters, which account for the
general frame of the model and the physical characteristics of the phenomenon; the
next section provides a better explication of the elements in the following list:
P={p
c
, p
t
, p
adh
, p
f
, p
r
, p
rl
, p
mt
}
where:
o
p
c
is the edge of the cell;
o
p
t
is the temporal correspondence of a step of SCIDDICA;
o
p
adh
is the adhesion value, i.e. the debris thickness, that may not removed;
o
p
f
is the friction threshold for debris outflows;
o
p
r
is the relaxation rate of debris landslide outflows;
o
p
rl
is the run up loss at each
CA
step;
o
p
mt
is the activation threshold of the mobilisation;
o
p
er
is the erosion depth parameter;
: Q
7
•
Q
is the deterministic state transition for the cells in
R
.
The basic elements of the transition function will be sketched in the next section.
At the beginning of the simulation, we specify the states of the cells in
R
, defining
the initial
CA
configuration; the initial values of the substates are so initialised:
Q
a
assumes the morphology values except for the detachment area, where the
thickness of the landslide mass is subtracted from the morphology value;
Q
th
is zero everywhere except for the detachment area, where the thickness of
landslide mass is specified;
Q
r
assumes initial values equal to the substate
Q
th
;
Q
d
assumes initial values corresponding to the maximum depth of the mantle of
detrital cover, which can be eroded;
Q
o
and
Q
i
are zero everywhere.
At each next step, the function
is applied to all the cells in
R
, so that the
configuration changes in time and the evolution of the
CA
is obtained.
3.3 The SCIDDICA Transition Function (S3hex Release)
Four local processes are considered for the release S3hex of SCIDDICA:
altitude, run up and debris thickness variation by detrital cover mobilisation;
run up variation by friction;
