Use of simulation for the prevention of environmental problems

The prevention of environmental disasters due to changes of meteorological conditions and to uncontrolled technological developments, is one of the most important objects of the future generations. The present work wants to show how the use of sophisticated techniques of simulation allows to prevent natural phenomena, responsible of serious damages to persons and things. We have considered the residential and commercial district of a city of southern Italy, built in the area of an old riverbed of outflow of raining waters. A change of meteorological conditions caused unexpected and abundant meteorological precipitations and a subsequent flooding (10/22/2005). The applied methodology allowed to demonstrate that the building activities in the region have caused the damages occurred to the population during the above natural events.

Actually, there isn't a standard and general method able to value potential dangers and to define the areas characterized by a different risk of flooding, to realize a risk assessment.

However, in our work, we have followed the guided lines supplied by National Basin Authorities, in particular of the Puglia region.

The work can be divided into three parts:

1) Cognitive Phase

- Acquisition of cartographical data of the region.

- Acquisition of data about meteorological precipitations.

- Census of historical events of flood, through official sources (for example: the hydrographical service of the Puglia region).

- Survey of the altitude of the area under investigation.

2) Hydrological Analysis

- Hydrological-statistical analysis of the historical data of some meteorological stations in the region.

- Characterization of the morphology of the hydrological basin.

- Definition of the curves of climatic possibility.

- Construction of the hydro-charts of flood relating to different conditions of meteorological precipitations, on the basis of a model of inflow and outflow.

- Evaluation of the hydro-charts of the considered area, in particular of the closing section.

3) Hydraulic Analysis

- Implementation of the hydraulic model.

- Esteem of the river profiles related to specific conditions of overflow.

- Calibration of the hydraulic model according to events of flood.

- Evaluation of the hydrometric levels.

- Esteem of the most important hydrodynamics factors (water average speed, Froud number etc.)