Sustainable Risk Management of Rural Road Networks Exposed to Natural Hazards: Application to Volcanic Lahars in Chile

Abstract

Natural hazards may temporarily or permanently interrupt the normal operation of rural road networks. The potential social, economic, environmental and physical impacts of natural events on rural road infrastructures empirically evidence the need to incorporate a sustainable risk approach to manage rural road networks exposed to natural hazards. Available risk management systems are applied to major networks emphasizing the physical risk of road infrastructure in terms of expected economic losses and travel time delays, without considering a systemic approach and other dimensions of risk, such as social vulnerability and the consequent socio-economic effects. The study proposes a sustainable risk management framework for rural roads that accounts for the social vulnerability of rural population, the physical vulnerability of rural roads and the environmental context in terms of natural hazards. The proposed framework is applicable to rural road networks exposed to major natural events that permanently or temporarily disrupt accessibility and mobility in the system. A case study is selected from a developing country, due to the socio-economic condition of the rural population and high vulnerability in the context of natural events. The proposed risk management framework is scaled at the network level rather than an element based analysis, or project level approach, considering the interdependencies between road links, the variability of road infrastructure types in the rural context, and the impacts on network accessibility and mobility due to natural events. The proposed framework is applied to a rural road network exposed to volcanic hazard, specifically lahar flows that are usually the most recurrent and disruptive process in terms of road infrastructure. Outcomes demonstrate that rural population present high social vulnerability levels, resulting in a slower recovery when exposed to the effects of infrastructure disruptions. Therefore, considering social vulnerability under a sustainable risk management approach depicts the sustainable role of rural road networks, which commonly are managed only under a physical vulnerability perspective. The proposed methodology will allow road agencies and municipalities to design sustainable mitigation and recovery strategies by incorporating dimensions such as social vulnerability, probability of failure of road links and their impacts on road accessibility and mobility due to natural hazards.

Seismic Vulnerability Assessment Methodologies for Roadway Assets and Networks: A State-of-the-Art Review

“…Mainly, the integration approach is considered more effective in determining road network vulnerability, as it tests various parameters and their impact on each other. The integration can be done for studying different parameters and their effect on each other [166]. For instance, Kilanitis and Sextos [96] studied the functionality of a road network considering the economic and environmental consequences.…”

Hazard and risk assessment for early phase road planning in Norway.

“…The historic events are taken from the national landslide inventory (https://temakart.nve.no/tema/SkredHendelser). The landslide susceptibility zones (1)(2)(3)(4) in Norway, when the relative sea level was higher than at present. Hence, the quick clay can only be developed in areas below the Holocene marine limit, which in Norway varies from zero in the southwest, to about 220 m elevation north of Oslo.…”

“…Other studies focus on sustainable and cost-effective mitigation measures at already de ned hazardous spots (Zumbrunnen et al 2017). Chamorro et al (2020) propose a methodology to allow road agencies and municipalities to design sustainable mitigation and recovery strategies by incorporating dimensions such as social vulnerability, probability of failure of road links and their impacts on road accessibility and mobility, using an example of volcanic hazards in Colombia. Doll et al (2013) discuss the costs of adapting railroads and roads to weather extremes, using examples from Germany and Austria.…”

Sensitivity analysis and uncertainty quantification of a seismic risk model for road networks

“…These equations have been applied in extreme conditions resulting from natural event disruptions (e.g., Chamorro et al, 2020; L. Chang, Elnashai, et al, 2012; Fan et al, 2010, 2020; Jayaram & Baker, 2010; Kiremidjian et al, 2007). For example Feng et al.…”