Table 2 Factors that can contribute to surface transportation closure during ashfall. This excludes interdependencies from impacts to other infrastructure, as it is difficult to consider all factors when producing fragility functions
| Â | Details for surface transportation mode | |||||
|---|---|---|---|---|---|---|
Road | Rail | Airport | Maritime | |||
Factors that contribute to closure | Hazard | Ash characteristics | Thickness, density on ground, settling rate / airborne concentration, particle size, shape / irregularity, colour, wetness, soluble components, hardness, friability. | |||
Meteorological conditions | Precipitation (rain, snow, hail, sleet), humidity, temperature, fog, ice, wind speed and direction. | |||||
Asset | Static infrastructure type and condition | Priority of infrastructure, requirement for emergency operations (e.g. evacuation, transport of goods), users, capacity, critical infrastructure interdependencies. | ||||
Sealed or unsealed surfaces and properties, slope of road, road marking properties, drainage. | Track and ballast properties, overhead line and pylon properties (if electric), gradient, station facilities, track-locomotive communications, collision avoidance systems. | Sealed or unsealed surfaces and properties, length of runway/s, terminal facilities, landing system technology. | Port facilities and technology. | |||
Mobile infrastructure type and condition | Fuel supply, extent of autonomous operation, requirement for emergency operations (e.g. evacuation, transport of goods). | |||||
Petroleum or electric, drive of vehicles (e.g. four-wheel drive, rear wheel drive), tyres, weight, power and torque, ground clearance, differential, traction control, transmission. | Electric or diesel locomotives and interchangability, locomotive-track communications, collision avoidance systems. | Aircraft type (e.g. turboprop, turbine engine, helicopter), on-board technology (e.g. volcanic ash avoidance systems). | Vessel type and method of mobility (e.g. cargo ship, ferry, yacht), size and weight, on-board technology (e.g. GPS and automatic identification systems). | |||
Impact | Impact type | Visibility impairment, signage and lighting covered, air filter blockage, engine failure due to ash ingestion, abrasion (bodywork and windscreens), cracked windscreens, health concerns. | ||||
Skid resistance reduction, road marking coverage, vehicles stuck, traffic light and variable message sign failures. | Track grip reduced, ballast contamination (potential for reduced cushioning), signal/switch failure, trains stuck. | Skid resistance reduction, light and airfield marking coverage, airspace closure. | Pumice raft obstruction to navigation, sedimentation in channels, accumulation of tephra on vessels. | |||
Preparedness / Mitigation | Population attributes | Frequency of ashfall events in area, prior vehicle operation in environments containing ash, knowledge sharing and traditions. | ||||
Organisational involvement | Infrastructure providers, local authorities, regional government, emergency management, national government, scientific research and monitoring organisations, goods and service logistic companies, other businesses, aid agencies, cleaning and disposal organisations. | |||||
Motoring associations, residents. | Rail companies. | Airport operators, Civil Aviation Authority, Volcanic Ash Advisory Centres. | Maritime bodies, harbourmasters. | |||
Physical measures | Cleaning of static and mobile infrastructure, drainage system changes, air filter maintenance and replacement, light and signage alterations, diversions. | |||||
Bridge strengthening, road surface and marking alterations, vehicle alterations, driving advice. | Bridge strengthening, ballast and track alterations, locomotive alterations, locomotive driver training changes. | Airfield surface and marking alterations, terminal facility changes, aircraft adaptations, pilot training changes. | Port facility changes, vessel adaptations, captain / helmsman training changes. | |||