Publication Date:
2009
abstract:
The present communication describes several regional-scale
modelling experiences involving the carbonatic aquifer of Mt
Coscerno and the alluvial aquifer of Petrignano d'Assisi. The aim is
to highlight the principal differences and similarities in the application
of mathematical models to carbonatic aquifers in mountain areas
and to alluvial type aquifers resulting principally from the different
availability of data. In the first case the hydrogeological balance,
determined by field measurements, is usually known while direct
observation of the piezometric surface is difficult owing to its
extreme depth; in the second case, the piezometric surface is determined
by measurement of piezometric level in wells although the
aquifer balance is generally known only through indirect estimates of
the effective infiltration and any other ancillary contributions
(exchanges with watercourses, infiltration from boundaries, etc). The
determination of the hydrodynamic parameters, wherever this is possible
by means of pumping tests, in any case has only a local meaning
and is influenced by the scale factor.
This results in different approaches both to the processing of the
conceptual model and in the phase of calibrating the numerical
model: in simulating carbonatic aquifers the calibration target consists
of the balance, as constrained by the geometry of the system
within a reasonable range of hydraulic heads and transmissivity values.
In the case of alluvial aquifers the simulation target consists of
the piezometric heads within a reasonable estimate of the balance and
of the range of the hydrodynamic parameters.
The aim is to demonstrate that, despite the difference in approach
to the reconstruction of the conceptual model, in one case based
essentially on the knowledge of the balance, and in the other of the
piezometric heads, the validity of the numerical models described is
in our view comparable.
Iris type:
01.01 Articolo in rivista
List of contributors: