Geoscience Reference
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be well simulated under some conditions of roughness coecient, inflow
discharge and slot area. In addition, many problems arose for acquisition
and reduction of underground geographical data.
In view of these situations, a solid numerical simulation model named
the storage pond model
3
is developed for underground inundation based
on a pond model. This model is simpler than the above stated models.
The data required for the model is reduced. Also, this model can treat
both ground and underground inundation simultaneously without much
diculty. In this paper, the storage pond model is applied to the central
area with underground spaces in two large cities in Japan, Fukuoka City
and Kyoto City. Fukuoka City is the central one of western Japan, whose
population is about 1.4 million, while Kyoto City is the old capital, whose
population is about 1.5 million. The inundation flow behaviors in both
ground and underground there are studied in detail.
2. Simulation Method
Underground spaces such as shopping mall are generally composed of
stores, open spaces, subway entrances and basements of adjacent build-
ings. Although the total underground mall may be very complicated, it can
be divided into some parts. If each part is assumed to be a storage pond
that has its own volume, the underground space is expressed by the com-
bination of storage ponds in the three dimensions (see Fig. 1). The slot
is also incorporated in each pond taking into account the pressurized flow
condition. Thus, the dispersion of inundation water can be expressed by
obtaining the discharge flowing between the adjacent storage ponds. For
the inundation on the ground surface, the similar method can be applied,
without slot in each pond.
Fig. 1.
Storage pond model.
