VALLE DI CLUS n. 466

Transcript

1 VALLE DI CLUS n. 466

2 STATO DI FATTO E MOTIVAZIONI RELATIVE ALLA REVISIONE CON RIPERIMETRAZIONE L area di indagine considerata rimane ubicata nel settore centrale dell abitato di Livigno, in sponda destra del torrente Spoel. Essa è rappresentata da una zona valanghiva propriamente detta, che si origina dal versante nordoccidentale del Monte della Neve. La zona è stata già oggetto di analisi e valutazioni nel 2002, in occasione dell aggiornamento dello studio geologico comunale, a cui pertanto si rimanda per eventuali consultazioni. In occasione del presente lavoro si è voluto riverificare la situazione, alla luce sia delle numerose osservazioni effettuate negli ultimi 10 anni, sia per un miglior adattamento dei parametri alla realtà dei luoghi. Le nuove simulazioni sono state effettuate utilizzando il software AVAL 1D. Si fornisce una tavola di riferimento della zonazione pregressa, per eventuali raffronti. La zonazione del 2002, corrispondente alla zona rossa, risulta riportata anche nel quadro P.A.I., attualmente in vigore (parte E del presente studio) e classificata Ve. Servizi Geologici e Nivologici Bellano Lc - Italy 2

3 SIMULAZIONI DINAMICHE E RISULTATI Per le simulazioni é stata utilizzata la cartografia prodotta nel 2002 e la verifica è stata effettuata lungo le stesse sezioni. Il volume di neve considerato è stato mantenuto costante e pari a circa mc. I risultati ottenuti sono in linea con quelli del E stata introdotta una zonazione gialla, cautelativa fino alla strada comunale principale, per considerare il caso di una componente aeriforme in condizioni eccezionali. Inoltre, per verificare la situazione relativamente ai lavori di estrazione (cava), è stata fatta una simulazione trentennale, con ampliamento laterale della zona di arresto, per tenere conto di una possibile valanga successiva, con deviazione verso la zona laterale meridionale. E stata così introdotta una ulteriore zonazione per la parte laterale del conoide, con ampliamento della zona rossa e blu. Possibili interferenze in zona di accumulo con strade comunali, pista di fondo, zona di estrazione, fabbricati, questi ultimi in zona blu e gialla. Servizi Geologici e Nivologici Bellano Lc - Italy 3

4 Studio e redazione PZEV con revisione e aggiornamento Piano Valanghe Comune di Livigno So Servizi Geologici e Nivologici Bellano Lc - Italy 4

5 Studio e redazione PZEV con revisione e aggiornamento Piano Valanghe Comune di Livigno So Servizi Geologici e Nivologici Bellano Lc - Italy 5

6 ********************************* A V A L - 1 D --- L O G F I L E ********************************* Date of Calculation: Thu Aug 27 08:29: Name of the corresponding output file: D:\AVA\livigno2009\466\sezAaa'_300.idl ************************************ S I M U L A T I O N R E S U L T S ************************************ Reason for the End of the Simulation Simulation stopped at TimeT = s due to the low Mass Flux Condition (Total Mass/2500/s) of 61 m3/s General Simulation Parameters Calculated Return Period: 300 years Overall Max Velocity: m/s Overall Max Height: 6.00 m Total Volume in System: m3 Minimal Mass Flux Condition: 61 m3/s Total Mass in System: t Mass Error in System: e-002 Percent Parametric Description of the Runout Zone Maximal Depth at the last simulation step: 2.09 m Position of Maximal Depth: a) projected avalanche length: m b) altitude above sealevel: m Mean Mass Position (half of the mass above/below this position) : a) projected avalanche length: m b) altidude above sea level: m Projected Length considered for Mean Deposition Depth Calculation (+/- one standard deviation from Mean Mass Position) from m to m Mean Deposition Depth : 1.31 m Monitoring Points P1: - Max Velocity m/s - Max Height 4.54 m Projected Distances and Heights in the Avalanche Track Limit between High and Low pressure Zone: 30.0 kpa Limit defining end of Low Pressure Zone: 0.3 kpa Distance Begin of Starting Zone - End of High Pressure Zone: 2023 m Distance Begin of Starting Zone - End of Low Pressure Zone: 2101 m Distance End of High Pressure Zone - End of Low Pressure Zone: 78 m Height above sealevel of End of High Pressure Zone: m Servizi Geologici e Nivologici Bellano Lc - Italy 6

7 Height above sealevel of End of Low Pressure Zone: m ---> Control Value of Length of the Avalanche: 2130 m Distance P1 - End of High Pressure Zone: 438 m Distance P1 - End of Low Pressure Zone: 516 m Summary of the comparison to the Control Values Subject Sim. Val. Ctrl. Val. Percentage Avalanche Length [m]: Flow Velocity Points: P1 [m/s]: Flow Height Points: P1 [m]: *************************** E N D O F R E S U L T S *************************** ******************** I N P U T D A T A ******************** (Copy of the '*.ava' - Input File) AVAL-1D INPUT FILE SLF-PROGRAM FOR ONE-DIMENSIONAL AVALANCHE SIMULATIONS VERSION 1.2, November 2001 ===================================================== NAME AND INFORMATION Track_Name sezaaa'_300 Run_Name INFO DENSE FLOW GLOBAL PARAMETERS Elem_Size 10.0 Dump_Interval 1.0 Max_Time 300 Return_Period 300 Red_Blue_Limit 30.0 Blue_White_Limit 0.3 Rho 300 Lambda 2.5 Time_Step Endmark x Endmark y COORDINATES Number_of_Points 15 No X Y Z W Servizi Geologici e Nivologici Bellano Lc - Italy 7

8 MONITORING POINTS Monitoring Points 1 Node Nr. Name Obs V Obs H 8 P DENSE FLOW LOCAL PARAMETERS No Mu Xi h Rel Canal Slope Dist Vel END OF AVAL-1D INPUT FILE ========================= *********************************************** E N D O F A V A L - 1 D --- L O G F I L E *********************************************** RUN_NAME: D:\AVA\livigno2009\466\466Aaa'_300L+ Servizi Geologici e Nivologici Bellano Lc - Italy 8

9 ********************************* A V A L - 1 D --- L O G F I L E ********************************* Date of Calculation: Thu Aug 27 08:57: Name of the corresponding output file: D:\AVA\livigno2009\466\sezAaa'_300L+.idl ************************************ S I M U L A T I O N R E S U L T S ************************************ Reason for the End of the Simulation Simulation stopped at TimeT = s due to the low Mass Flux Condition (Total Mass/2500/s) of 61 m3/s General Simulation Parameters Calculated Return Period: 300 years Overall Max Velocity: m/s Overall Max Height: 6.00 m Total Volume in System: m3 Minimal Mass Flux Condition: 61 m3/s Total Mass in System: t Mass Error in System: e-002 Percent Parametric Description of the Runout Zone Maximal Depth at the last simulation step: 1.77 m Position of Maximal Depth: a) projected avalanche length: m b) altitude above sealevel: m Mean Mass Position (half of the mass above/below this position) : a) projected avalanche length: m b) altidude above sea level: m Projected Length considered for Mean Deposition Depth Calculation (+/- one standard deviation from Mean Mass Position) from m to m Mean Deposition Depth : 1.04 m Monitoring Points P1: - Max Velocity m/s - Max Height 4.54 m Projected Distances and Heights in the Avalanche Track Limit between High and Low pressure Zone: 30.0 kpa Limit defining end of Low Pressure Zone: 0.3 kpa Distance Begin of Starting Zone - End of High Pressure Zone: 2004 m Distance Begin of Starting Zone - End of Low Pressure Zone: 2072 m Distance End of High Pressure Zone - End of Low Pressure Zone: 68 m Height above sealevel of End of High Pressure Zone: m Height above sealevel of End of Low Pressure Zone: m Servizi Geologici e Nivologici Bellano Lc - Italy 9

10 ---> Control Value of Length of the Avalanche: 2130 m Distance P1 - End of High Pressure Zone: 419 m Distance P1 - End of Low Pressure Zone: 487 m Summary of the comparison to the Control Values Subject Sim. Val. Ctrl. Val. Percentage Avalanche Length [m]: Flow Velocity Points: P1 [m/s]: Flow Height Points: P1 [m]: *************************** E N D O F R E S U L T S *************************** ******************** I N P U T D A T A ******************** (Copy of the '*.ava' - Input File) AVAL-1D INPUT FILE SLF-PROGRAM FOR ONE-DIMENSIONAL AVALANCHE SIMULATIONS VERSION 1.2, November 2001 ===================================================== NAME AND INFORMATION Track_Name sezaaa'_300l+ Run_Name INFO DENSE FLOW GLOBAL PARAMETERS Elem_Size 10.0 Dump_Interval 1.0 Max_Time 300 Return_Period 300 Red_Blue_Limit 30.0 Blue_White_Limit 0.3 Rho 300 Lambda 2.5 Time_Step Endmark x Endmark y COORDINATES Number_of_Points 15 No X Y Z W Servizi Geologici e Nivologici Bellano Lc - Italy 10

11 MONITORING POINTS Monitoring Points 1 Node Nr. Name Obs V Obs H 8 P DENSE FLOW LOCAL PARAMETERS No Mu Xi h Rel Canal Slope Dist Vel END OF AVAL-1D INPUT FILE ========================= *********************************************** E N D O F A V A L - 1 D --- L O G F I L E *********************************************** RUN_NAME: D:\AVA\livigno2009\466\466Aaa'_30 ********************************* A V A L - 1 D --- L O G F I L E ********************************* Servizi Geologici e Nivologici Bellano Lc - Italy 11

12 Date of Calculation: Thu Aug 27 08:41: Name of the corresponding output file: D:\AVA\livigno2009\466\sezAaa'_30.idl ************************************ S I M U L A T I O N R E S U L T S ************************************ Reason for the End of the Simulation Simulation stopped at TimeT = s due to the low Mass Flux Condition (Total Mass/2500/s) of 43 m3/s General Simulation Parameters Calculated Return Period: 30 years Overall Max Velocity: m/s Overall Max Height: 3.33 m Total Volume in System: m3 Minimal Mass Flux Condition: 43 m3/s Total Mass in System: t Mass Error in System: e-009 Percent Parametric Description of the Runout Zone Maximal Depth at the last simulation step: 1.92 m Position of Maximal Depth: a) projected avalanche length: m b) altitude above sealevel: m Mean Mass Position (half of the mass above/below this position) : a) projected avalanche length: m b) altidude above sea level: m Projected Length considered for Mean Deposition Depth Calculation (+/- one standard deviation from Mean Mass Position) from m to m Mean Deposition Depth : 1.00 m Monitoring Points P1: - Max Velocity m/s - Max Height 2.36 m Projected Distances and Heights in the Avalanche Track Limit between High and Low pressure Zone: 30.0 kpa Limit defining end of Low Pressure Zone: 0.3 kpa Distance Begin of Starting Zone - End of High Pressure Zone: 1869 m Distance Begin of Starting Zone - End of Low Pressure Zone: 1984 m Distance End of High Pressure Zone - End of Low Pressure Zone: 116 m Height above sealevel of End of High Pressure Zone: m Height above sealevel of End of Low Pressure Zone: m ---> Control Value of Length of the Avalanche: 2130 m Distance P1 - End of High Pressure Zone: 284 m Servizi Geologici e Nivologici Bellano Lc - Italy 12

13 Distance P1 - End of Low Pressure Zone: 399 m Summary of the comparison to the Control Values Subject Sim. Val. Ctrl. Val. Percentage Avalanche Length [m]: Flow Velocity Points: P1 [m/s]: Flow Height Points: P1 [m]: *************************** E N D O F R E S U L T S *************************** ******************** I N P U T D A T A ******************** (Copy of the '*.ava' - Input File) AVAL-1D INPUT FILE SLF-PROGRAM FOR ONE-DIMENSIONAL AVALANCHE SIMULATIONS VERSION 1.2, November 2001 ===================================================== NAME AND INFORMATION Track_Name sezaaa'_30 Run_Name INFO DENSE FLOW GLOBAL PARAMETERS Elem_Size 10.0 Dump_Interval 1.0 Max_Time 300 Return_Period 30 Red_Blue_Limit 30.0 Blue_White_Limit 0.3 Rho 300 Lambda 2.5 Time_Step Endmark x Endmark y COORDINATES Number_of_Points 15 No X Y Z W Servizi Geologici e Nivologici Bellano Lc - Italy 13

14 MONITORING POINTS Monitoring Points 1 Node Nr. Name Obs V Obs H 8 P DENSE FLOW LOCAL PARAMETERS No Mu Xi h Rel Canal Slope Dist Vel END OF AVAL-1D INPUT FILE ========================= *********************************************** E N D O F A V A L - 1 D --- L O G F I L E *********************************************** RUN_NAME: D:\AVA\livigno2009\466\466Aaa'_30rrL+ ********************************* A V A L - 1 D --- L O G F I L E ********************************* Date of Calculation: Mon Sep 07 11:03: Name of the corresponding output file: D:\AVA\livigno2009\466\sezAaa'_30rrL+.idl Servizi Geologici e Nivologici Bellano Lc - Italy 14

15 ************************************ S I M U L A T I O N R E S U L T S ************************************ Reason for the End of the Simulation Simulation stopped at TimeT = s due to the low Mass Flux Condition (Total Mass/2500/s) of 43 m3/s General Simulation Parameters Calculated Return Period: 30 years Overall Max Velocity: m/s Overall Max Height: 3.34 m Total Volume in System: m3 Minimal Mass Flux Condition: 43 m3/s Total Mass in System: t Mass Error in System: e-009 Percent Parametric Description of the Runout Zone Maximal Depth at the last simulation step: 2.25 m Position of Maximal Depth: a) projected avalanche length: m b) altitude above sealevel: m Mean Mass Position (half of the mass above/below this position) : a) projected avalanche length: m b) altidude above sea level: m Projected Length considered for Mean Deposition Depth Calculation (+/- one standard deviation from Mean Mass Position) from m to m Mean Deposition Depth : 1.25 m Monitoring Points P1: - Max Velocity m/s - Max Height 2.38 m Projected Distances and Heights in the Avalanche Track Limit between High and Low pressure Zone: 30.0 kpa Limit defining end of Low Pressure Zone: 0.3 kpa Distance Begin of Starting Zone - End of High Pressure Zone: 1840 m Distance Begin of Starting Zone - End of Low Pressure Zone: 1965 m Distance End of High Pressure Zone - End of Low Pressure Zone: 124 m Height above sealevel of End of High Pressure Zone: m Height above sealevel of End of Low Pressure Zone: m ---> Control Value of Length of the Avalanche: 2130 m Distance P1 - End of High Pressure Zone: 255 m Distance P1 - End of Low Pressure Zone: 380 m Summary of the comparison to the Control Values Servizi Geologici e Nivologici Bellano Lc - Italy 15

16 Subject Sim. Val. Ctrl. Val. Percentage Avalanche Length [m]: Flow Velocity Points: P1 [m/s]: Flow Height Points: P1 [m]: *************************** E N D O F R E S U L T S *************************** ******************** I N P U T D A T A ******************** (Copy of the '*.ava' - Input File) AVAL-1D INPUT FILE SLF-PROGRAM FOR ONE-DIMENSIONAL AVALANCHE SIMULATIONS VERSION 1.2, November 2001 ===================================================== NAME AND INFORMATION Track_Name sezaaa'_30rrl+ Run_Name INFO DENSE FLOW GLOBAL PARAMETERS Elem_Size 10.0 Dump_Interval 1.0 Max_Time 300 Return_Period 30 Red_Blue_Limit 30.0 Blue_White_Limit 0.3 Rho 300 Lambda 2.5 Time_Step Endmark x Endmark y COORDINATES Number_of_Points 15 No X Y Z W Servizi Geologici e Nivologici Bellano Lc - Italy 16

17 MONITORING POINTS Monitoring Points 1 Node Nr. Name Obs V Obs H 8 P DENSE FLOW LOCAL PARAMETERS No Mu Xi h Rel Canal Slope Dist Vel END OF AVAL-1D INPUT FILE ========================= *********************************************** E N D O F A V A L - 1 D --- L O G F I L E *********************************************** Servizi Geologici e Nivologici Bellano Lc - Italy 17

18 Servizi Geologici e Nivologici Bellano Lc - Italy 18