The June 19, 1996 hydrogeological catastrophe in Versilia and Garfagnana (Tuscany, Italy): geomorphological aspects and hydraulic evaluation. The rainfall that occurred in Versilia and part of Garfagnana on June 19, 1996 was exceptionally heavy: the 13 hour rain attained 478 mm in Alta Versilia and 420 mm in Garfagnana (in the basin of the Versilia River, the average rain per year is 1430 mm). The valleys of the Vezza River in Alta Versilia and of the Turrite di Gallicano Stream in Garfagnana were the most affected. The greatest damages were suffered by villages in the valley bottoms: Cardoso (nearly destroyed) and Fornovolasco (partially destroyed). Several landslides invaded the main and secondary roads, also taking away long stretches of them. The consequences of the flood were remarkable in the plain too: the Versilia River, which originates from the union of the Vezza River with the Serra Stream just before it flows into the plain, broke its left bank for about 70 m in correspondence with an artificial bight (the deviation was made some centuries ago to drain the Porta Lake), overflowing in a heavily populated area, flooding 8 km2 and breaking off the Aurelia highway and the Roma-Genova railway. The features of the landslides are related to the geologic, lithologic and morphologic parameters of the slopes. As for the plain, frequently flooded by the Versilia River, we attempted a calculation of the high flows with assigned return period; from the examination of the results, it appears that the flow rate capable of making overflows have a return period shorter than 10 years. Intensive measures are suggested to prevent catastrophic events, both in the plain and in the mountainous region .
La catastrofe idrogeologica del 19/6/1996 in Versilia e Garfagnana (Toscana, Italia): aspetti geomorfologici e valutazioni idrauliche
D'AMATO AVANZI, GIACOMO ALFREDO;PUCCINELLI, ALBERTO;
1998-01-01
Abstract
The June 19, 1996 hydrogeological catastrophe in Versilia and Garfagnana (Tuscany, Italy): geomorphological aspects and hydraulic evaluation. The rainfall that occurred in Versilia and part of Garfagnana on June 19, 1996 was exceptionally heavy: the 13 hour rain attained 478 mm in Alta Versilia and 420 mm in Garfagnana (in the basin of the Versilia River, the average rain per year is 1430 mm). The valleys of the Vezza River in Alta Versilia and of the Turrite di Gallicano Stream in Garfagnana were the most affected. The greatest damages were suffered by villages in the valley bottoms: Cardoso (nearly destroyed) and Fornovolasco (partially destroyed). Several landslides invaded the main and secondary roads, also taking away long stretches of them. The consequences of the flood were remarkable in the plain too: the Versilia River, which originates from the union of the Vezza River with the Serra Stream just before it flows into the plain, broke its left bank for about 70 m in correspondence with an artificial bight (the deviation was made some centuries ago to drain the Porta Lake), overflowing in a heavily populated area, flooding 8 km2 and breaking off the Aurelia highway and the Roma-Genova railway. The features of the landslides are related to the geologic, lithologic and morphologic parameters of the slopes. As for the plain, frequently flooded by the Versilia River, we attempted a calculation of the high flows with assigned return period; from the examination of the results, it appears that the flow rate capable of making overflows have a return period shorter than 10 years. Intensive measures are suggested to prevent catastrophic events, both in the plain and in the mountainous region .I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
