Table 3 Volcanic ash-induced damage type matrix (source: Daly and Wilkie, 1999 )
From: The genesis of volcanic risk assessment for the Auckland engineering lifelines project: 1996–2000
Structure | Ash thickness <1 mm | Ash thickness 1-5 mm | Ash thickness 5 - 100 mm | Ash thickness >100 mm |
|---|---|---|---|---|
Pipework | ||||
Open systems (ie stormwater) | Blockage depending on water (or sewage turbidity) | Blockage depending on water (or sewage turbidity) | Blockage depending on water (or sewage turbidity) | Blockage depending on water (or sewage turbidity) |
Closed systems | N/A | N/A | N/A | N/A |
Building structures | ||||
Flat-roof | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage to metal roofs; loading damage potential for flat roofed structures, moderate if dry (high over 300 mm), high if wet. |
Pitched-roofs (>20°) | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage on metal roofs, especially if freshly painted | Corrosion damage to metal roofs, low to moderate risk of load damage depending on roof pitch. |
Building services | ||||
Air-conditioning | Abrasion damage to moving parts. | Abrasion damage to moving parts. | Blockage, abrasion damage to moving parts. | Blockage, abrasion damage to moving parts. |
Gutters | Blockage from reworked ash. | Blockage from reworked ash, load damage. | Blockage from reworked ash, load damage. | Blockage from reworked ash, load damage. |
Electricity Services | ||||
Power lines | N/A | Loading, tree breakages onto lines | Loading, tree breakages onto lines | Loading, tree breakages onto lines |
Power line insulators | N/A | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. |
Substations | N/A | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. Abrasion damage to moving parts. | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. Abrasion damage to moving parts. | Short-circuiting (flashover), low potential if ash is dry, high if ash is wet. Abrasion damage to moving parts. |
Civil Structures | ||||
Roads | N/A | Blockage, reduced traction and visibility | Blockage, reduced traction and visibility | Blockage, reduced traction and visibility |
Rail | N/A | Reduced traction and visibility, short-circuiting of electric signals if ash is wet. | Reduced traction and visibility, short-circuiting of electric signals if ash is wet. | Blockage, reduced traction and visibility, short-circuiting of electric signals if ash is wet. |
Wastewater | ||||
Sewage pumps | Abrasion damage to moving parts (depends on turbidity of sewage) | Abrasion damage to moving parts (depends on turbidity of sewage) | Abrasion damage to moving parts (depends on turbidity of sewage) | Abrasion damage to moving parts (depends on turbidity of sewage) |
Sewage treatment plant | Abrasion damage to moving parts (depends on turbidity of sewage) | Abrasion damage to moving parts (depends on turbidity of sewage), damage to pond oxidation process. | Abrasion damage to moving parts (depends on turbidity of sewage), damage to pond oxidation process. | Abrasion damage to moving parts (depends on turbidity of sewage), damage to pond oxidation process. |
Water Supply Systems | ||||
River/Stream | pH and turbidity contamination | pH and turbidity contamination | pH and turbidity contamination | pH and turbidity contamination |
Uncovered reservoir | Turbidity contamination | pH and turbidity contamination | pH and turbidity contamination | pH and turbidity contamination |
Cover reservoir/ground water | N/A | N/A | N/A | N/A |
Roof-fed tank | Chemical, pH and turbidity contamination | Chemical, pH and turbidity contamination | Chemical, pH and turbidity contamination | Chemical, pH and turbidity contamination |
Telecommunications | ||||
Lines | N/A | Loading, tree breakage onto lines | Loading, tree breakage onto lines | Loading, tree breakage onto lines |
Microwave towers | N/A | Corrosion of metal surfaces. | Corrosion of metal surfaces. | Corrosion of metal surfaces, possible load damage. |
Exchange equipment: | ||||
External air-conditioning | Short-circuiting (flashover) of equipment, abrasion damage to moving parts | Short-circuiting (flashover) of equipment, abrasion damage to moving parts | Short-circuiting (flashover) of equipment, abrasion damage to moving parts | Short-circuiting (flashover) of equipment, abrasion damage to moving parts |
Internal air-conditioning | N/A | N/A | N/A | N/A |
Specific infrastructure | ||||
Ports | Potential corrosion and abrasion damage to port facilities | Potential corrosion and abrasion damage to port facilities | Potential corrosion and abrasion damage to port facilities | Potential corrosion and abrasion damage to port facilities |
Airports - Air transport | Potential corrosion and abrasion damage to aircraft and airport (communications) installations | Potential corrosion and abrasion damage to aircraft and airport (communications) installations | Potential corrosion and abrasion damage to aircraft and airport (communications) installations | Potential corrosion and abrasion damage to aircraft and airport (communications) installations, loading damage potential for flat roofed structures, moderate if dry (high over 300 mm), high if wet. |